Pharmacology introduction.basic concepts,pharmacognosy1.pptx

Definition of Terms
• Pharmacognosy: Study of natural drugs like herbs and other plant products used
for treatment purposes.
• Pharmacy: The branch of science that deals with manufacture, packing, storage
and dispensation of drugs
Drug Nomenclature: it the naming and classifying of drugs
Chemical Name is a scientific name that precisely describes the drug’s atomic
and molecular structure. e.g. for Panadol its Paraaminophenol
Generic Name: or nonproprietary, name is an abbreviation of the chemical
name. in many cases it is the name of the active compound of a drug. For
Panadol it is called Paracetamol
Trade/Brand Name: This is the name given to a drug by a company and is
normally the name of the discoverer of the drug and is named by the
pharmaceutical name e.g. Panadol having different names like Dawanol but
the drug has the same active compound

Trade names are protected by copyright. The symbol ® after a trade
name indicates that the name is registered by and restricted to the
drug manufacturer.
To avoid confusion, it’s best to use a drug’s generic name because any
one drug can have a number of trade names.

Pharmacologic drug classification
Drugs that share similar characteristics are grouped together
as a pharmacologic class (or family). Beta-adrenergic blockers
are an example of a pharmacologic class.
A second type of drug grouping is the therapeutic class, which
categorizes drugs by therapeutic use. Antihypertensives are an
example of a therapeutic class.

Sources of Drugs
Drugs can be obtained from;
• Plants e.g. Digitalis, Quinine etc
• Animals e.g. Insulin obtained from pancreas of pigs in old times,
epinephrine from adrenal medulla of animals, vaccines from horses
• Minerals and Mineral products e.g. iron tablets from iron ore to treat
pernicious anemia, iodine found in salt etc
• Synthetic compounds e.g. in molecular engineering, manipulating
bacteria to produce drugs. This is the current technique of making
drugs and has been used to make things like NaHCO3 and other
superoxides
• Microbes

Constituents of Drugs
Most contain
• 1.alkaloids having C, H, N and O for example Atropin, Morphine and
caffeine from coffee. These are insoluble mostly Others contain
• 2.glycosides; on hydrolysis yield a carbohydrate and other chemical
groupings like aldehyde, an acid, an alcohol etc e.g. the drug digitalis From
• 3.plant exudates like gum and swell in presence of water to form
gelatinous or muculagenous masses e.g. methyl cellulose, agar
• 4. Resins; Is an extraction from a crude drug; some are colorless and some
are aromatic and some are obtained from the sap of trees. A resin is
insoluble in water but soluble in alcohol ether and other oils. They may be
irritating and some are used as cathetics e.g. Podophylin, Balsams (have
got resins + benzoic acids)

Constituents of Drugs Contd…
• 5. Oils; Are substances insoluble in water and highly viscous and may be
volatile or fixed. Volatile oils give an aroma but may also be irritating,
stimulating and may have antiseptic effects like peppermint. Fixed oils feel
greasy and don’t evaporate easily and when hydrolyzed a fatty acid is
formed and glycerine e.g. olive oil, castor oil or sesame oil

DOSAGE FORMS OF DRUGS
• Dosage form is a product suitable for administration of a drug to a
patient. Every active ingredient (drug) has to be formulated by adding
other substances ( excipients, diluents, preservatives vehicles, etc.)
according to a specific recipe and packaged into a specific 'dosage
form' eg tablet, elixir, ointment. injection vial, etc. which is then
administered to the subject.
• The dosage form provides body to the drug, demarkates single doses,
protects the active ingredient(s), and makes it suitable for
administration in various ways

DOSAGE FORMS OF DRUGS cont’d
• Solid dosage forms
• Powders
• Tablets (chewable, dispersible, sublingual, enteric coated, sustained release, controlled
release
• Pills
• Capsules
• Lozenges
• Suppositories
• Liquid dosage forms
• Aqueous solutions
• Suspensions
• Elixirs
• Drops
• Lotions
• Injections
• Semisolid dosage forms
• Ointments
• Pastes
• Gels

Factors governing choice of route
1. Physical and chemical properties of the drug (solid/ liquid/gas; solubility,
stability, pH, irritancy).
2. Site of desired action—localized and approachable or generalized and not
approachable.
3. Rate and extent of absorption of the drug from different routes.
4. Effect of digestive juices and first pass metabolism on the drug.
5. Rapidity with which the response is desired (routine treatment or
emergency).
6. Accuracy of dosage required (intravenous and inhalational can provide
fine tuning).
7. Condition of the patient (unconscious, vomiting).

ROUTES OF DRUG ADMINSTRTION
• LOCAL ROUTES
• These routes can only be used for localized lesions at
accessible sites and for drugs whose systemic
absorption from these sites is minimal or absent.
• high concentrations are attained at the desired site
without exposing the rest of the body.
• Systemic side effects or toxicity are absent or minimal
• some can serve as systemic route of administration,
e.g.glycery l trinitrate (GTN) applied on the skin as
ointment or transdermal patch for angina pectoris

LOCAL ROUTES
• 1. Topical This refers to external application of the
drug to the surface for localized action
• 2 . Deeper tissues Certain deep areas can be
approached by using a syringe and needle, but the
drug should be in such a form that systemic
absorption is slow, e.g. intra-articular injection
(hydrocortisone acetate in knee joint)
• 3. Arterial supply Close intra-arterial injection is used
for contrast media in angiography; anticancer drugs
can be infused in femoral or brachial artery to localise
the effect for limb malignancies

SYSTEMIC ROUTES
The main routes of administration are:
• oral
• sublingual
• rectal
• application to other epithelial surfaces (e.g. skin, cornea, vagina and nasal mucosa)
• inhalation
• nasal
• injection (parenteral)
- subcutaneous
- intramuscular
- intravenous
- intrathecal.

Routes of admin ctd….
(A) Oral administration-Most drugs are taken by mouth and
swallowed. Absorption mainly in small intestine. About 75% of a drug
given orally is absorbed in 1-3 hours, but numerous factors alter this:
• gastrointestinal motility
• blood flow to site of absorption
• particle size and formulation
• physicochemical factors

• NB for most drugs taken orally they undergo the first- pass
metabolism ie when drug then passes through the liver, where
metabolism and biliary excretion may occur before the drug enters
the systemic circulation and bioavailability may be reduced
substantially.

Routes of admin ctd…….
Advantages of the oral route
• Safe
• Convenient
• Economical
• Avoidance of complications of parenteral therapy

Routes of admin ctd…
Disadvantages
• Onset of drug action is delayed not suitable for emergencies
• Irritant and unpalatable drugs cannot be administered eg chloramphenicol
• Not useful ion the presence of diarrhoea and vomiting
• Destruction by digestive enzymes e.g insulin, penicillin G
• Undergoes first pass metabolism which reduces bioavailability eg GTN
testosterone etc
• Irregular, erratic and negligible absorption of some drugs e.g.
aminoglycosides
• Cannot be used in unconscious and uncooperative patients

(B) Sublingual Administration or buccal
Absorption from the oral mucosa the surface area available is small but
venous drainage from the mouth is to the superior vena cava, which
protects the drug from rapid hepatic first-pass metabolism. E.g
nitroglycerin, buprenorphine, desamino-oxytocin
• Only lipid soluble and non-irritating drugs can be so administered.
• Absorption is relatively rapid

(C) Rectal Administration-useful when oral ingestion is precluded
because the patient is unconscious,vomiting or in young children.
• Approximately 50% of the drug will bypass the liver; therefore hepatic
first-pass metabolism.
• However, absorption often irregular and incomplete, and many drugs
can cause irritation of the rectal mucosa

(D) Injection. The major routes of administration are:
• Intravenous (IV)
• subcutaneous (SC)
• Intramuscular (IM)
• Intrathecal (IT)
• Intraarterial

1. Intravenous- bioavailability is complete (100%) and rapid.Drug
delivery is controlled and achieved with an accuracy and immediacy
not possible by any other route

Advantages
• almost instantaneous absorption of a drug into the blood
• avoidance of hepatic first-pass loss
• in the case of pulmonary disease, local application of the drug at the
desired site of action eg in asthma

(F) Topical administration
• mucous membranes eg the conjunctiva, nasopharynx, oropharynx,
vagina, colon, urethra, and urinary bladder primarily for their local
effects. Occasionally,eg application of synthetic antidiuretic hormone
to the nasal mucosa, systemic absorption is the goal

• Cutaneous administration-used when a local effect on the skin is
required (e.g. topically applied steroids). Appreciable absorption may
nonetheless occur and lead to systemic effects.
- also have transdermal dosage forms, in which the drug is
incorporated in a stick-on patch applied eg oestrogen for hormone
replacement. Produce a steady rate of drug delivery and avoid
presystemic metabolism

Pharmacokinetics
Pharmacokinetics
The term kinetics refers to movement. Pharmacokinetics deals with a drug’s actions
as it moves through the body. Therefore pharmacokinetics principles discuss how a
drug is:
• absorbed (taken into the body)
• distributed (moved into various tissues)
• metabolized (changed into a form that can be excreted)
• excreted (removed from the body).
This branch of pharmacology is also concerned with a drug’s
onset of action, peak concentration level, and duration of action.

Absorption
Absorption
Drug absorption covers the progress of a drug from the time it’s
administered, through the time it passes to the tissues, until it becomes available
for use by the body. How drugs are absorbed
On a cellular level, drugs are absorbed by several means primarily through active or
passive transport.

Absorption
Passive transport requires no cellular energy because the drug moves from an area
of higher concentration to one of lower concentration (diffusion). It occurs when
small molecules diffuse across membranes. Diffusion stops when the drug
concentrations on both sides of the membrane are equal.
Oral drugs use passive transport; they move from higher concentrations in the GI
tract to lower concentrations in the bloodstream.
Active transport requires cellular energy to move the drug from an area of lower
concentration to one of higher concentration. Active transport is used to absorb
electrolytes, such as sodium and potassium, as well as some drugs, such as
levodopa.

Absorption
Pinocytosis is a unique form of active transport that occurs when a cell engulfs a drug
particle. Pinocytosis is commonly employed to transport the fat-soluble vitamins (A, D,
E, and K).
Factors affecting absorption
Various factors such as the route of administration, the amount of blood flow, and the
form of the drug can affect the rate of a drug’s absorption.

• Number of cell separating the active drug
Fast absorption If only a few cells separate the active drug from systemic
circulation, absorption occurs rapidly and the drug quickly reaches therapeutic
levels in the body. Typically, drug absorption occurs within seconds or minutes
when administered sublingually, IV, or by inhalation.
Slow but steady absorption occurs at drugs are administered by the oral, IM, or
subcut routes because the complex membrane systems of GI mucosal layers,
muscle, and skin delay drug passage.
At the slowest absorption, drugs can take several hours or days to reach peak
concentration levels. A slow rate usually occurs with rectally administered or
sustained-release drugs.

• Intestinal interference
Several other factors can affect absorption of a drug. For example, most absorption of
oral drugs occurs in the small intestine. If a patient has had large sections of the small
intestine surgically removed, drug absorption decreases because of the reduced surface
area and the reduced time the drug is in the intestine
• Liver-lowered levels
Drugs absorbed by the small intestine are transported to the liver before being circulated
to the rest of the body. The liver may metabolize much of the drug before it enters
circulation. This mechanism is referred to as the first-pass effect. Liver metabolism may
inactivate the drug; if so, the first-pass effect lowers the amount of active drug released
into the systemic circulation. Therefore, higher drug dosages must be administered to
achieve the desired effect.

Factors affecting absorption ctd
• Increased blood flow to an absorption site improves drug absorption,
whereas reduced blood flow decreases absorption. More rapid absorption
leads to a quicker onset of drug action. For example, the muscle area selected
for IM administration can make a difference in the drug absorption rate.
• Blood flows faster through the deltoid muscle (in the upper arm) than through
the gluteal muscle (in the buttocks). The gluteal muscle, however, can
accommodate a larger volume of drug than the deltoid muscle.

Pain and stress can also decrease the amount of drug absorbed. This may be
due to a change in blood flow, reduced movement through the GI tract, or
gastric retention triggered by the autonomic nervous system’s response to pain.
High-fat meals and solid foods slow the rates of absorption the focus here
looks at gastric contents hindering entry of the drug to the intestines, delaying
intestinal absorption of a drug.

Drug dosage form (such as tablets, capsules, liquids, sustained-release formulas,
inactive ingredients, and coatings) affects the drug absorption rate and the time
needed to reach peak blood concentration levels.
For example, enteric-coated drugs are specifically formulated so that they don’t
dissolve immediately in the stomach. Rather, they release in the small intestine.
Liquid forms, however, are readily absorbed in the stomach and at the beginning
of the small intestine.

Drug-Drug & Food-Drug Considerations
• Combining one drug with another drug or with food can cause interactions that
increase or decrease drug absorption, depending on the substances involved.

Distribution
Drug distribution is the process by which the drug is delivered to the tissues and
fluids of the body. Distribution of an absorbed drug within the body depends on
several factors, including:
• blood flow
• solubility
• protein binding.
After a drug has reached the bloodstream, its distribution in the body depends on
blood flow. The drug is distributed quickly to those organs with a large supply of
blood, including the heart, liver, and kidneys. Distribution to other internal organs,
skin, fat, and muscle is slower

Distribution
• The ability of a drug to cross a cell membrane depends on whether
the drug is water- or lipid- (fat-) soluble. Lipid-soluble drugs easily
cross through cell membranes, whereas water-soluble drugs can’t.
Lipid-soluble drugs can also cross the blood-brain barrier and enter
the brain.
• As a drug travels through the body, it comes in contact with proteins,
such as the plasma protein albumin. The drug can remain free or bind
to the protein. The portion of a drug that’s bound to a protein is
inactive and can’t exert a therapeutic effect. Only the free, or
unbound, portion remains active. A drug is said to be highly protein-
bound if more than 80% of it binds to protein.

Metabolism
Drug metabolism, or biotransformation, refers to the body’s ability to
change a drug from its dosage form to a more water-soluble form that
can then be excreted. Drugs can be metabolized in several ways:
• Most commonly, a drug is metabolized into inactive metabolites
(products of metabolism), which are then excreted.
• Some drugs can be converted to active metabolites, meaning they’re
capable of exerting their own pharmacologic action. These metabolites
may undergo further metabolism or may be excreted from the body
unchanged.
• Other drugs can be administered as inactive drugs, called prodrugs,
and don’t become active until they’re metabolized.

Metabolism ctd
• Most drugs are metabolized by enzymes in the liver; however, metabolism can also
occur in the plasma, kidneys, and membranes of the intestines. Some drugs inhibit
or compete for enzyme metabolism, which can cause the accumulation of drugs
when they’re given together. This accumulation increases the potential for an
adverse reaction or drug toxicity.
• Certain diseases can reduce metabolism. These include liver disease, such as
cirrhosis, and heart failure, which reduces circulation to the liver.
• Genetics allow some people to be able to metabolize drugs rapidly, whereas others
metabolize them more slowly.

Metabolism ctd
Environmental effects
Environment, too, can alter drug metabolism. For example, if a person is
surrounded by cigarette smoke, the rate of metabolism of some drugs may be
affected. A stressful environment, such as one involving prolonged illness or
surgery, can also change how a person metabolizes drugs.
Age alterations
Developmental changes can also affect drug metabolism. For example, infants have
immature livers that reduce the rate of metabolism, and elderly patients
experience a decline in liver size, blood flow, and enzyme production that also
slows metabolism.

Excretion
Drug excretion refers to the elimination of drugs from the body. Most drugs are
excreted by the kidneys and leave the body through urine. Drugs can also be
excreted through the lungs, exocrine glands (sweat, salivary, or mammary glands),
skin, and intestinal tract.
Drug Half-Life
• The half-life of a drug is the time it takes for the plasma concentration of a drug
to fall to half its original value in other words, the time it takes for one-half of the
drug to be eliminated by the body.
• Factors that affect a drug’s half-life include its rates of absorption, metabolism,
and excretion. Knowing how long a drug remains in the body helps determine
how frequently a drug should be taken.

Excretion-Drug Half-Life ctd
A drug that’s given only once is eliminated from the body almost completely after
four or five half-lives. A drug that’s administered at regular intervals, however,
reaches a steady concentration (or steady state) after about four or five half-lives.
Steady state occurs when the rate of drug administration equals the rate of drug
excretion.

Excretion
Onset, peak, and duration
In addition to absorption, distribution, metabolism, and excretion, three other
factors play important roles in a drug’s pharmacokinetics:
• onset of action
• peak concentration
• duration of action.
Onset of action refers to the time interval that starts when the drug is
administered and ends when the therapeutic effect actually begins. Rate of onset
varies depending on the route of administration and other pharmacokinetic
properties.

Excretion
As the body absorbs more drug, blood concentration levels rise. The peak
concentration level is reached when the absorption rate equals the elimination
rate. However, the time of peak concentration isn’t always the time of peak
response
The duration of action is the length of time the drug produces its therapeutic
effect.

Definition of a drug
• It is the single active chemical entity present in a medicine that is used
for diagnosis, prevention, treatment/ cure of a disease.
• WHO- a Drug is any substance or product that is used or is intended
to be used to modify or explore physiological systems or pathological
states for the benefit of the recipient.

PROPERTIES OF AN IDEAL DRUG
If we were developing a new drug, we would want it to be the best drug
possible. As such there are some guiding factors that we consider to every drug
to aim attaining for it to approach perfection It should however be noted that is
not such thing as a perfect drug,
The following are three key properties
• Effectiveness
An effective drug is one that elicits the responses for which it is given.
• Safety
A safe drug is defined as one that cannot produce harmful effects even if
administered in very high doses and for a very long time.
• Selectivity
A selective drug is defined as one that elicits only the response for which it is
given.

PROPERTIES OF AN IDEAL DRUG Ctd
Additional properties include
• Reversible Action
• Predictability
• Ease of Administration
• Freedom From Drug Interactions
• Low Cost
• Chemical Stability
• Possession of a Simple Generic Name

Definition of Terms
• Pharmacotherapeutics: The study of choice of drugs for the various
diseases and the choice depends on a number of factors like age, sex,
physiological status e.g. pregnancy, physical activity etc.
Therapeutics involves medical uses of drugs in diagnoses, prevention or
treatment of disease.
• The therapeutic objective: of drug therapy is to provide maximum
benefit with minimal harm.
If drugs were ideal, we could achieve this objective with relative ease.
However, because drugs are not ideal, we must exercise skill and care if
treatment is to result in more good than harm.

Definition of Terms
• Pharmacodynamics: The study of effects of drugs on the body e.g. increasing
heart beat, any visual side effects, affecting appetite, inducing nausea etc.
• Once a drug has reached its sites of action, pharmacodynamics processes
determine the nature and intensity of the response. Pharmacodynamics can
be thought of as the impact of drugs on the body.
• Pharmacokinetics: Reaction of the body to drugs, Pharmacokinetic processes
determine how much of an administered dose gets to its sites of action. There
are four major pharmacokinetic processes:
(1) drug absorption,
(2) drug distribution,
(3) drug metabolism,
(4) drug excretion.
Collectively, these processes can be thought of as the impact of the body on
drugs

Pharmacokinetics
Pharmacokinetics refers to what the body does to a drug.
• The following 4 pharmacokinetic properties determine the onset, intensity, and the
duration of drug action :
1). Absorption: Absorption from the site of administration permits entry of the drug (either
directly or indirectly) into plasma.
2). Distribution: The drug may then reversibly leave the bloodstream and distribute into the
interstitial and intracellular fluids.
3). Metabolism: The drug may be biotransformed by metabolism by the liver or other
tissues.
4). Elimination: The drug and its metabolites are eliminated from the body in urine, bile, or
faeces.
• Using knowledge of pharmacokinetic parameters, clinicians can design optimal drug
regimens, including the route of administration, the dose, the frequency, and the duration
of treatment.

Schematic depiction of pharmacokinetic processes

Pharmacodynamics
• What the drug does to the body. This includes physiological and
biochemical effects of drugs and their mechanism of action at
organ system/subcellular/macromolecular levels.
e.g.—Adrenaline → interaction with adrenoceptors → G-
protein mediated stimulation of cell membrane bound adenylyl
cyclase → increased intracellular cyclic 3´,5´AMP → cardiac
stimulation, hepatic glycogenolysis and hyperglycaemia.

EXCRETION
• Excretion is the passage out of systemically absorbed drug. Drugs and their
metabolites are excreted in:
1. Urine: Through the kidney. It is the most important channel of excretion
for majority of drugs.
2. Faeces: Apart from the unabsorbed fraction, most of the drug present in
faeces is derived from bile.
3. Exhaled air Gases and volatile liquids (general anaesthetics, alcohol) are
eliminated by lungs, irrespective of their lipid solubility.
4. Saliva and sweat These are of minor importance for drug excretion.
5. Milk The excretion of drug in milk is not important for the mother, but
the suckling infant inadvertently receives the drug.

Trade names are protected by copyright. The symbol ® after a trade
name indicates that the name is registered by and restricted to the
drug manufacturer.
To avoid confusion, it’s best to use a drug’s generic name because any
one drug can have a number of trade names.
Official Name: Is an alternative name e.g. for panadol is
Acetaminophen

Sources of Drugs
Drugs can be obtained from;
• Plants e.g. Digitalis, Quinine etc
• Animals e.g. Insulin obtained from pancreas of pigs in old times,
epinephrine from adrenal medulla of animals, vaccines from horses
• Minerals and Mineral products e.g. iron tablets from iron ore to treat
pernicious anemia, iodine found in salt etc
• Synthetic compounds e.g. in molecular engineering, manipulating
bacteria to produce drugs. This is the current technique of making
drugs and has been used to make things like NaHCO3 and other
superoxides

Dosage Forms
• This is the preparation of how you give a drug and can be given;
• Enterally; this means orally in terms of tablets, pills, enteric coated tablets,
capsules, syrups and other liquid preparations. It can also be rectally besides
orally and include suppositories and enemas
• Parenterally:
• Can be inhaled in terms of solid particles, vaporized or nebulized (making
particles fly).
• There can be also in form of injections and are in terms of intradermal
(through skin) e.g. BCG and measles vaccines and several tests.
• Can also be subcutaneous (just below the skin) e.g. insulin, some fluids.
• Then the intramuscular route for colloid suspensions and the intravenous
route for boluses of drugs of continuous infusion via drip then intraarterial
route for angiograms via dyes to arteries.

• We also have intrathecal injections via the spinal cord in the sub arachnoid
space mostly between C1 and C2 and include steroids and certain cytotoxics.
• Peritoneal route via the peritoneum especially when veins cannot be seen
especially in children and burn victims
• Intramedullary given straight in the bone but is rarely used
• Intraarticular through the joint especially for severe arthritis
• Transcutaneous routes include very thin fluids passing straight through the
skin
• Jet injection technique via skin by forcing the drug via pressure instead of
injection, passes through the skin pores via patches by sticking to the skin e.g.
rehabilitation of smokers or insulin administration for diabetics
Injectable dosage Forms and where they
administered

Other dosage forms and where they are
administered
Emulsions; via skin
• Transmucosal route via mucous membrane
• Trans-nasaly e.g. using nasal sprays or light creams on the nose and is
absorbed via the mucous membrane of the nose
• Transrectal route via the rectum e.g. using suppositories especially when the
mouth is impaired from opening
• Vaginal tablets; Transvaginal used mainly in vaginal infections and during fetal
abortion
• Transurethral; small tablets pushed via urethra
• Trans-conjuctival route, via the conjunctiva e.g. using eye drops
• Syringe pumps; for example for insulin and GRH-Gonadotropin Releasing
Hormone

Enteric-coated preparations:
• An enteric coating is a chemical envelope that protects the drug
from stomach acid, delivering it instead to the less acidic intestine,
where the coating dissolves and releases the drug.
• Enteric coating is useful for certain drugs (for example, omeprazole)
that are acid unstable.
• Drugs that are irritating to the stomach, such as aspirin, can be
formulated with an enteric coating that only dissolves in the small
intestine, thereby protecting the stomach.

Extended-release preparations:
• Extended-release (abbreviated ER or XR) medications have special coatings or
ingredients that control the drug release, thereby allowing slower absorption
and prolonged duration of action.
Advantages of ER
• ER formulations can be dosed less frequently and may improve patient
compliance.
• ER formulations maintain concentrations within the therapeutic range over a
longer period of time, as opposed to immediate-release dosage forms.
• ER formulations are advantageous for drugs with short half-lives.
Eg: the half-life of oral morphine is 2 to 4 hours, and it must be administered
six times daily to provide continuous pain relief. However, only two doses are
needed when extended release tablets are used.

Routes of administration
Classification
• Routes of administration can broadly be divided into:
• Topical: Local effect, substance is applied directly where its action is desired.
• Enteral: Desired effect is systemic (non-local), substance is given via the digestive tract.
• Parenteral: Desired effect is systemic, substance is given by routes other than the
digestive tract e.g. via the rectum (anal) or per vagina
Topical
• Epicutaneous (application onto the skin), e.g. allergy testing, typical local anesthesia
• Inhalational, e.g. asthma medications
• Enema, e.g. contrast media for imaging of the bowel
• Eye drops (into the conjunctiva), e.g. antibiotics for conjunctivitis
• Ear drops - such as antibiotics and corticosteroids for Otitis Externa

Routes of administration Contd…
• Intranasal Route (into the nose), e.g. decongestant nasal sprays. Nasal
administration can also be used for systemic effect. This is related to the
transmucosal route through a mucous membrane via insufflation.
• Vaginal, e.g. topical estrogens, antibacterials
Enteral
• Enteral is any form of administration that involves any part of the gastrointestinal
tract:
• By mouth (orally), many drugs as tablets, capsules, or drops
• By gastric feeding tube, duodenal feeding tube, or gastrostomy, many drugs and
enteral nutrition
• Rectally, various drugs in suppository or enema form

Drug discovery
• Drug discovery is a process which aims at identifying a compound
therapeutically useful in curing and treating disease.
• Disease are controlled at molecular and physiological level,
• Shape of a molecule at the atomic level is known.
• So how do we discover drugs????Drugs have been discovered either by
identification of the active ingredient from traditional remedied or by
serendipity.

Drug discovery methods
• Serendipity
• Random screening
• Molecular design
• Drug metabolites.

Stages of drug discovery and development
process.
1.Target identification
2. Target validation
3. lead identification
4. lead optimization
5.Product characterization
6.Formulation and development
7. Preclinical research
8. Investigational New Drug
9. Clinical trials
10.New Drug Application
11. Approval
.

Drug discovery process.
1)Target Identification The first step in the discovery of a drug is
identification of the biological origin of a disease, and the potential
targets for intervention.
2) Target Validation: is the process by which the expected
molecular target – for example gene, protein or nucleic acid of a
small molecule is certified. Target validation includes: determining
the structure activity relationship (SAR) of analogs of the small
molecule.
3) Identification of Lead A chemical lead is defined as a
synthetically stable, feasible and drug like molecule that is active in
assay and has acceptable specificity, affinity and selectivity for the
receptors.
4) Lead optimization is the process by which a drug candidate is
designed after an initial lead compound is identified. The process
involves iterative series of synthesis and characterization of a
potential drug to build up a representation of in what way chemical
structure and activity are related in terms of interactions with its
targets and its metabolism.

5)Product Characterization When any new drug molecule
shows a promising therapeutic activity, then the molecule is
characterized by its size, shape, strength, weakness, use,
toxicity, and biological activity.
6) Formulation and Development Pharmaceutical
formulation is a stage of drug development during which the
physicochemical properties of active pharmaceutical
ingredients (APIs) are characterized to produce a
bioavailable, stable and optimal dosage form for a specific
administration route.
7)Preclinical Testing :Pre-clinical research in drug
development process involves evaluation of drug‘s safety and
efficacy in animal species .

8) The Investigational New Drug Process (IND) Drug developers must
file an Investigational New Drug application to Regulatory bodies before
commencement of clinical research.
9) Clinical Research Clinical trials are conducted in people (volunteer)and
intended to answer specific questions about the safety and efficacy of
drugs, vaccines, other therapies, or new methods of using current
treatments. Clinical trials follow a specific study protocol that is designed
by the researcher or investigator or manufacturer.

Phases of clinical trials
• Phase I the drug is tested on healthy volunteers to make sure the drug can be
given safely to people.
• Phase II involves trials with human subjects who have the disease for which the
drug is thought to be effective.
• Phase III Large numbers of patients in medical research centers Receive the drug
in phase III. This larger sampling provides Information about infrequent or rare
adverse effects. The FDA approves a new drug application if phase III studies are
satisfactory.
• Phase IV is voluntary and involves post-market surveillance of the drug’s
therapeutic effects at the completion of phase III The pharmaceutical company
receives reports from doctors and other health care professionals about the
therapeutic results and adverse effects of the drug

10) New Drug Application A New Drug Application (NDA) expresses the full story of a drug
molecule. Its purpose is to verify that a drug is safe and effective for its proposed use in the
people studied.
11)Approval

Prescription and non-prescription drugs
• As per drug rules, majority of drugs including all antibiotics must be sold in retail only
against a prescription issued to a patient by a registered medical practitioner. These are called
‘prescription drugs.
• However, few drugs like simple analgesics (paracetamol aspirin), antacids, laxatives (senna,
lactulose), vitamins, ferrous salts, etc. are considered relatively harmless, and can be procured
without a prescription. These are ‘non-prescription’ or ‘over the-counter’ (OTC) drugs.

 Dose’ is the appropriate amount of a drug needed to produce a certain degree of response in
a given patient.
 Adverse Drug Effects: any undesirable or unintended consequence of drug
administration’. It includes all kinds of noxious effect—trivial, serious or even fatal.
• Adverse effects may develop promptly or only after prolonged medication or even after
stoppage of the drug.
 Side effects: These are unwanted but often unavoidable pharmacodynamics effects that
occur at therapeutic doses.
 Indication: use of drug to treat a particular disease. eg, diabetes is an indication for
insulin OR insulin is indicated for the treatment of diabetes.

• Contraindication: specific situation in which a drug, procedure, or surgery should not be
used because it may be harmful to the person.
There are two types of contraindications:
i). Relative contraindication means that caution should be used when two drugs or procedures are
used together. (It is acceptable to do so if the benefits outweigh the risk.)
Eg: a person who takes warfarin to thin the blood should not take aspirin, which is a blood
thinner.
ii).Absolute contraindication means that event or substance could cause a life-threatening
situation. A procedure or medicine that falls under this category must be avoided.
Eg: Certain decongestants are contraindicated in people with high blood pressure and
should be avoided.

drug-receptor interaction
Agonist : An agent which activates a receptor to produce an effect similar to that of the
physiological signal molecule.
Inverse agonist: An agent which activates a receptor to produce an effect in the opposite
direction to that of the agonist.
Antagonist: An agent which prevents the action of an agonist on a receptor or the subsequent
response, but does not have any effect of its own.
Partial agonist: An agent which activates a receptor to produce submaximal effect but
antagonizes the action of a full agonist.

• Drug half life: How long it takes for half of the dose to be eliminated from the bloodstream.
Therefore half-life of a drug is the time it takes for the plasma concentration of a drug to reach half of its
original concentration.
• Pharmacogenetics: is the study of how genes affect a person's response to drugs. This relatively new field
combines pharmacology (the science of drugs) and genomics (the study of genes and their functions) to
develop effective, safe medications and doses that will be tailored to a person's genetic makeup.
• Therapeutic efficacy: The capacity for beneficial change (or therapeutic effect) of a given intervention (for
example a drug, medical device, surgical procedure, or a public health intervention).
• Therapeutic window/index: Comparison of the amount of a therapeutic agent that causes
the therapeutic effect to the amount that causes toxicity. (A ratio that compares the blood concentration at
which a drug becomes toxic and the concentration at which the drug is effective).

Placebo: Substance or treatment with no active therapeutic effect. An inactive substance or
preparation used as a control in an experiment or test to determine the effectiveness of a
medicinal drug.
Drug intolerance: or drug sensitivity refers to an inability to tolerate the adverse effects of
a medication, generally at therapeutic or sub therapeutic doses.
Potency : Is a measure of drug activity expressed in terms of the amount required to produce
an effect of given intensity. ... Affinity is how well a drug can bind to a receptor (Fast/strong
binding = higher affinity).

Introduction writing……
PRESCRIPTION
Definition
Parts of a prescription
Handling of prescription
Samples

Definition
Prescription
A prescription is an order written by a physician, dentist
or any other medical practitioner to the pharmacist to
compound and dispense a specific medication for an
individual patient

Continuation……
A prescription is actually a direct link between physicians,
pharmacists and patients
Prescriptions are accompanied by directions for pharmacists
and for patients

Parts of a prescription
A. Heading
• Date
• Personal data of patient
B. Body
• Superscription
• Inscription
• Subscription
C. Closing
• Signature of patient
• Signature of physician

Date
Date should mention when was the prescription done, for
time sensitive prescriptions include hours and minutes
where necessary
Dates are also indicated for drugs with special time
scheduling e.g. clomiphene
This helps the pharmacist in re-dispensing a medicine and to
guide the patient
They also helps record keeping and retrieval

Personal data of the patient
It includes but not limited to
• Name
• Sex
• Age
• Address
Clinically relevant data where necessary includes
• Blood type
• BMI a derivative of Height & Weight
• BSA

Inscription
It is the main part of the prescription. It contains the name
and quantity of the prescribed ingredients
It also contains the directions on how the medication should
be taken
Additionally it may contain directions on storage requirements

Subscription
This part contains the prescriber’s directions to the
pharmacist
It includes
• Type of dosage form
• Number of doses to be dispensed

Signature of Physician
Prescriptions must be signed with the prescribers own
hand
Address and registration details of the prescriber
should be written in case of dangerous drugs

Handling of prescriptions
• Receiving
• Dosage calculation
• Compunding
• Finishing
• Pricing
• Delivering

Receiving of Prescriptions
Pharmacist should himself receive the
prescription.
It includes
 reading the prescription
Checking the prescription

Reading the prescription:-
Prescription should be completely and carefully read
from top to bottom
Checking of prescriptions:-
Prescriptions should be checked for any incompatibility

Finishing the prescription
It includes
•Packaging
•Labelling
•Rechecking
•Filling

Labelling continued
Label information
• Types of prescription
• Name age and sex of patient
• Date of dispensing
• Storage conditions
• Name and address of pharmacy
• In-case of liquid preparations attach auxiliary label
Shake well before use
• Route of administration

• Dose’ is the appropriate amount of a drug needed to produce a
certain degree of response in a given patient.
• Accordingly, dose of a drug has to be qualified in terms of the
chosen response, . Eg the analgesic dose of aspirin for headache is
0.3–0.6 g, its antiplatelet dose is 60–150 mg/ day, while its
antiinflammatory dose for rheumatoid arthritis is 3–5 g per day.
• Similarly there could be a prophylactic dose, a therapeutic dose or a
toxic dose of the same drug.
• The dose of a drug is governed by its inherent potency, i.e. the

Strategies adopted for different types of drugs and conditions
1. Standard dose The same dose is appropriate for most patients—individual
variations are minor or the drug has a wide safety margin so that a large
enough dose can be given to cover them.
2. Regulated dose The drug modifies a finely regulated body function which
can be easily measured. The dosage is accurately adjusted by repeated
measurement of the affected physiological parameter, e.g. hypoglycaemics.
3. Target level dose The response is not easily measurable but has been
demonstrated to be obtained at a certain range of drug concentration in plasma.
An empirical dose aimed at attaining the target level is given in the beginning
and adjustments are made later by actual monitoring of plasma concentrations.

4. Titrated dose The dose needed to produce maximal therapeutic
effect cannot be given because of intolerable adverse effects. Optimal
dose is arrived at by titrating it with an acceptable level of adverse
effect. Low initial dose and upward titration (in most non-critical
situations) or high initial dose and downward titration (in critical
situations) can be practised. Often a compromise between
submaximal therapeutic effect but tolerable side effects can be struck,
e.g. anticancer drugs, corticosteroids.

 PHARMACOTHERAPY
 aims at a therapy that is –
EFFECTIVe
SAFE
INDIVIDUALIZED(for each
patient’s need)
AFFORDABLE
RATIONAL (not Irrational)
 Successful Therapy depends on the
“TISSUE-RESPONSE to the Drug”
3
SELECTIVE

CLINICAL PHARMACOKINETICS
HIGHER the DOSE MORE the EFFECT
NO
?? DIRECTLY
PROPORTIONAL
%
R
E
S
P
O
N
S
E
D O S E
RESPONSE is
PROPORTIONAL
to Log-DOSE
Log-D O S E
%
R
E
S
P
O
N
S
E
%
R
E
S
P
O
N
S
E
D O S E
ACTUALLY
IT IS
4
TISSUE RESPONSE
(Therapeutic Effect)
DOSE DEPENDENT

 RESPONSE DEPENDS ON “TARGET TISSUE
CONCENTRATION” OF DRUG
 CAN DRUG CONCENTRATION BE EASILY
MONITORED IN “TARGET TISSUES”?
e.g. in Heart, Brain ??
NO!!!!
6

TARGET TISSUE CONCENTRATION
BLOOD / PLASMA CONCENTRATION
(which is easily monitored)
DRUG’S PLASMA
CONCENTRATION
DEPEND ON ???
IS IN EQUILIBRIUM WITH
7

BLOOD / PLASMA CONCENTRATION DEPENDS ON
2. HOW DRUG
DISTRIBUTES to
Different Body
Compartments
3. HOW DOES
DRUG GET
ELIMINATED
from Body
1. HOW MUCH
DRUG reaches
Blood from sites
of administration
127

DISTRIBUTION
• Volume of
Distribution (Vd)
• Barriers
ELIMINATION
•HALF LIFE
Biotransformation
Excretion
BLOOD / PLASMA CONCENTRATION DEPENDS ON
ABSORPTION
•Bioavailability
•Dose
DRUG
128

∴Plasma Concentration Depends on 3 factors -
2.
Volume of
Distribution (Vd)
3.
HALF LIFE (T ½ )
1.
Bioavailability
129

 THE EXTENT (& RATE) TO WHICH THE ADMINISTERED
DOSE IS AVAILABLE IN BLOOD IN UNCHANGED FORM
(i.e. available for action in target tissues)
 EXPRESSED AS % OR FRACTION (F)
 I.V. DOSE - BY DEFINITION ASSUMED TO BE 100%
BIOAVAILABLE (F = 1)
 ‘F’ BY OTHER ROUTES EXPRESSED RELATIVE TO I.V.
BIOAVAILABILITY
1. BIOAVAILABILITY (F)

PLASMA
CONCENTRATION
OF
DRUG
TIME
DRUG ADMINISTERED
I.V. DRUG
ORAL DRUG
AUC Oral
AUC i.v.
AUC Oral
BIOAVAILABILITY = -------------- x 100 (ORAL)
AUC i.v.
i.e. EXPRESSED AS % of I.V.,
which is assumed to be 100 %
OR as Fraction “F” (of I.V.)
 “30% (or 0.3)” means that 70%
(or 0.7 fraction) not absorbed
&/or destroyed in GIT/Liver
before reaching systemic
circulation
13
AUC = AREA UNDER CURVE

135
A. Variations in
DISINTEGRATION
TIME of Solids
B. Variations in
DISSOLUTION
TIME of Solids
C. SOLUBILITY
of drug
D. STABILITY
of drug

of Solids (Ta used in preparing Tablets
B.DISSOLUTION TIME of drug Particsintegration) can
Vary due to –
• PARTICLE SIZE
• PHYSICAL FORM - CRYSTALLINE/ AMORPHOUS
☞ THEREFORE POORLY SOLUBLE DRUGS –
(e.g. Griseofulvin, Spironolactone , Aspirin)

D. CHEMICAL STABILITY of drug to -
• ACID pH of Stomach (e.g. Penicillin G vs
Amoxilcillin)
• GUT ENZYMES - e.g. Insulin destroyed by GIT
enzymes

BIOEQUIVALENCE: is an important
clinical issue BECAUSE-

2.
VOLUME
OF
DISTRIBUTION
[ Vd , AVd]
142

2. Volume of Distribution (AVd)
143

EXTRACELLULAR
WATER
14 L
10 L 4 L
Interstitial
Volume
Plasma
Volume
Total Body H2O (60%)* 42L
Extra-cellular
-Interstitial
-Plasma Vol.
Intra-cellular
(20%)* 14L
(14%)* 10L
(06%)* 04L
(40%)* 28L
(* % of B Wt)
INTRACELLULAR
WATER
28 L
42 Liters
TOTAL BODY WATER
Plasma
Interstitial
Volume
Intracellular
Volume

TYPES OF ELIMINATION KINETICS
147

CALCULATING AVd OF A 1st ORDER DRUGcorrectly
 AVd = DOSE given  C0
(C0 = Plasma conc. at Zero hour after Drug inj.
i.e. instantly)
• EXPONENTIAL Curve
–Phase
 – Phase
PLASMA
CONC.
(Arithm.
scale)
0
1
2
3
4
5
0 1 2 3 4 5 6
TIME (hr)
I.V. DOSE
• 2 PHASES but not distinct
 – PHASE (Fast) of
Distribution of drug
 – PHASE (Slow)
of Drug Elimination
150

• Almost BI-LINEAR Curve
with 2 CLEAR SLOPES
•-Slope of Drug
Distribution (Fast)
•-Slope of Drug
Elimination (Slow)
– Phase
0 2 4 6 8 10 12
TIME (hr)
I.V. DOSE
PLASMA
CONC.
(Log.
scale)
1
2
4
8
16
32
64
0
If DOSE = 300 mg, & C = 30mg/L
AVd = 30030 = 10 L
• Extrapolate -Slope
back to get C0 =30 mg/L
–Phase
151

1. Vd TELLS US WHERE IN THE BODY, DRUG IS
LOCATED
2. Vd HELPS IN FINDING (the Starting) DOSE OF
A DRUG
3. Vd HELPS IN CORRECTING (Insufficient or
Excessive) DOSE OF A DRUG
4. Vd HELPS PREDICTING OF DISPLACEMENT
DRUG INTERACTIONS
5. Vd HELPS MAKE ADJUSTMENTS FOR
EXCESSIVE BODY WEIGHT VARIATIONS

A. Some drugs may be distributed
IN PLASMA ONLY
(Their Vd will be = approx 4 to 5 L)
28L
4L 10L
Plasma Interstitium
RBCs Intracellular
Space
CLINICAL IMPLICATIONS OF AVd
1. Vd TELLS US WHERE IN THE BODY, DRUG
IS LOCATED- ECF

B. Some drugs may be distributed in
EXTRA-CELLULAR FLUIDS ONLY
(Plasma + Interstitial fluid)
(Their Vd will be = approx 12-15 L)
RBCs Intracellular
Space
Vd TELLS WHERE DRUG IS LOCATED
ECF
Plasma Interstitium
4L 10L
28L

C. Lipophilic Drugs Cross Cell
Membranes & Distribute
UNIFORMLY IN TOTAL BODY WATER
(Their Vd will be = APPROX. 40 L)
Plasma Interstitium
4L 10L
28L
RBCs Intracellular
Space
Vd TELLS WHERE DRUG IS LOCATED-

D. Some drugs
• BIND STRONGLY TO TISSUES  So
their Plasma Levels are VERYLOW
Gives VERY HIGH Vd VALUE
(>100 L  DIGOXIN, CHLOROQUINE
which is unreal  So APPARENT Vd)
28L
4L 10L
Plasma Interstitium
RBCs Intracellular
Space
Vd TELLS WHERE DRUG IS LOCATED -

158
Vd =
DOSE
Plasma Conc.
Or DOSE = Vd x Plasma Conc.
(Needed) (Desired)
 Desired (Therapeutic) Plasma Conc. Range
for COMMUNITY is known for most Drugs
 Fine Titration of dose can subsequently be
done for INDIVIDUAL patient

4. Vd & DISPLACEMENT INTERACTIONS
160

162

47

164

3.
ELIMINATION OF DRUG
[ T ½ ]
165

ELIMINATION OF DRUG
168
WE WILL NOW DISCUSS MAINLY
FIRST ORDER KINETICS
(as most drugs follow it)

ELIMINATION OF DRUG – (How long drug stays in body?)

4. ELIMINATION RATE CONSTANT (Kel, ke, k):
173

CL ÷ Vd
Kel/ke/k =
CL
Is Amount eliminated per
Unit Time. It is present
in Plasma Cleared / U
time i.e. “CL” (Volume)
is actually contained
in Total Body Water
 i.e. “Vd” (Volume)
÷

Can Rewrite
equation to
find “CL”
from Kel & Vd 174
= Kel x Vd

1A. SINGLE I.V. DOSE (Bolus)
ELIMINATION OF 1ST ORDER DRUGS WHEN SINGLE I.V. DOS
IS GIVEN (as Bolus)
177

178
UNDERSTANDING DRUG’S
BEHAVIOR IN BLOOD & BODY?
How Long the Dose Stays in the Body
(or In How Much Time is the Dose
“Nearly Totally Eliminated”)

1A. SINGLE I.V. DOSE – GRAPHIC CALCULATION OF TIME
NEEDED FOR “NEAR TOTAL” ELIMINATION OF A DOSE?
Plasma Con. Falls to ½ its initial level:
from 3216 (50% Eliminated)
168 (50+25=75% Elimin)
84 (50+25+12.5% " " )
42 (50+25+12.5+6.25%
= 93.75% Elimin)
Each in 8 hr
Plasma Half
Life (T ½) of
Drug = 8 hr
I.V. DRUG
DISTRIBUTION
[α] PHASE
ELIMINATION
[β] PHASE
0 4 8 12 16 20 24 28 32 36
TIME (HOURS)
16
2
8
4
1
64
32
Plasma
Log-Concentration
(µg/mL)
8 hr
8hr
8hr
8hr
CPLASMA fell 93.75% (32 to 2 µg/ml) in 4 x T ½ (32 hr)63

Pharmacokinetics-Spot-1
Bioavailability (F) for the following
2 drugs is-
Propranolol
Atenolol
26%
56%
Q. What is the ONE MOST IMPORTANT Reason for
LOW Bioavailability of Propranolol?
(Answer in few words-Maximum one line)
Answer: First Pass Metabolism (or Pre-Systemic
Metabolism)

Vd (Volume of Distribution) for Digoxin is 500
Liters (per 70 kg.)
1. Where in the body is most of the drug
present?
(Answer in max 4-5 words)
2. Can Dialysis be useful in treating patient
with Digoxin overdose toxicity? (Answer
only as Yes or No)
Answer: 1. In Tissues;
2. No

For Theophylline
Desired Plasma Concentration (C)
= 10 mg/L
Volume of Distribution (Vd)
= 35 L (per 70kg)
Q. Calculate the Dose (needed) of Theophylline.
Answer: Dose = Vd x C i.e. 35x10=350 mg

FOR ATENOLOL-
DESIRED PLASMA CONCENTRATION (C) = 1mg/L
VOLUME OF DISTRIBUTION (Vd) = 67L ( per 70kg)
Q. Calculate the Dose (needed) of Atenolol.
Answer: Dose = Vd x C i.e. 67x1=67 mg

Drug 'X' was given in 20 mg Bolus Dose.
Plasma concentration at Time Zero (C0) was
found to be 5 mg/L
Q. What is the Vd (Volume of Distribution) for Drug
'X‘?
Answer: Vd = Dose/C i.e. 20/5 = 4 Liters

Two Samples 'A' & 'B', of the same drug showed following
absorption data-
56%
A B
57%
20 min 48 min
‘F' (Bioavailability)
T-max (time to reach
peak conc.)
1. Are the samples 'A' & 'B‘ Bioequivalent
or Bio-inequivalent?
2. Why/ Why not (few words-maximum one line)?
Answer: Q.1- Bio-inequivalent
Q.2- Differing Tmax, though AUC nearly
same.

For Paracetamol-
CL (Clearance)
'C' (Plasma concentration)
= 20 L/ hr
= 15 mg/L
Q. Calculate "Elimination Rate" of Paracetamol.
Answer:
Elim Rate = CLxC
= 20x15
= 300 mg/hr

For Drug 'X'-
Total Dose Given
Elimination Rate
=1000 mg
= 200 mg/hr
Q. Calculate the Elimination Rate Constant (Kel/
Ke/ K) of the Drug 'X'.
Answer:
Kel (or K) = Elim Rate/ Total Dose in body
= 200/1000
= 0.2/hr

Ciprofloxacin (T ½ = 4.1hr) is to be given for few
days to a patient.
Q. How much time will be needed for Ciprofloxacin
to reach the Steady State Concentration (Css)?
Answer:
4-5 T ½ needed;
i.e. 4.1x 4 or 5
= 16.4 to 20.5 hr

Fixed dose combinations (FDCs) of drugs
• Pharmaceutical preparations contain two or more drugs in a fixed dose
ratio.
Advantages offered by these are:
1. Convenience and better patient compliance— when all the
components present in the FDC are actually needed by the patient
and their amounts are appropriate. It may also be cost saving
compared to both/all the components administered separately.
2. Certain drug combinations are synergistic, e.g. sulfamethoxazole +
trimethoprim; combination oral contraceptives, isoniazid + rifampin.

3. The therapeutic effect of two components being same may add up
while the side effects being different may not. For this the
components of the FDC should act by different mechanisms, e.g.
amlodipine + atenolol as antihypertensive.
4. The side effect of one component may be counteracted by the other,
e.g. a thiazide + a potassium sparing diuretic. However, the amount
of the latter may not be sufficient in all cases.
5. Combined formulation ensures that a single drug will not be
administered. This is important in the treatment of tuberculosis, HIV-
AIDS and falciparum malaria.

Disadvantages FDCs:
1. The patient may not actually need all the drugs present in a
combination: he is subjected to additional side effects and expense.
2. The dose of most drugs needs to be adjusted and individualised.
When a combined formulation is used, this cannot be done without
altering the dose of the other component(s). However, few
combinations are available at more than one dose ratios, e.g.
amoxicillin (250 mg or 500 mg) + clavulanic acid (125 mg).
3. The time course of action of the components may be different:
administering them at the same intervals may be inappropriate.

4. Altered renal or hepatic function of the patient may differently
affect the pharmacokinetics of the components.
5. Adverse effect, when it occurs, cannot be easily ascribed to the
particular drug causing it.
6. Contraindication to one component (allergy, other conditions)
contraindicates the whole product.
7. Confusion of therapeutic aims and false sense of superiority of
two drugs over one is fostered, specially in case of antimicrobials
whose combinations should be avoided. Corticosteroids should
never be combined with any other drug meant for internal use.

FACTORS MODIFYING DRUG ACTION
1. Body size It influences the concentration of the drug attained at the site of
action. The average adult dose refers to individuals of medium built. For
exceptionally obese or lean individuals and for children dose may be calculated
on body weight (BW) basis.
2. Age The dose of a drug for children is often calculated from the adult dose.
Child dose = Age × adult dose ... (Young’s formula)
Age + 12
Child dose = Age × adult dose ... (Dilling’ formula)
20

3. Sex Females have smaller body size and require doses that are on the lower side of
the range.
• Subjective effects of drugs may differ in females because of their mental makeup.
• Maintenance treatment of heart failure with digoxin is reported to be associated
with higher mortality among women than among men. A number of
antihypertensives (clonidine, methyldopa, blockers, diuretics) have potential to
interfere with sexual function in males but not in females.
4. Species and race: Among human beings some racial differences have been
observed, e.g. blacks require higher and mongols require lower concentrations of
atropine and ephedrine to dilate their pupil. β- blockers are less effective as
antihypertensive in Afro-Caribbeans.
5. Genetics The dose of a drug to produce the same effect may vary by 4–6 fold among
different individuals. Key determinants of drug response, are transporters or even
metabolizing enzymes.

6. Route of administration: Governs the speed and intensity of drug response.
Parenteral administration is often resorted to for more rapid, more pronounced and more predictable drug action.
• A drug may have entirely different uses through different routes, e.g. magnesium sulfate given orally causes
purgation, applied on sprained joints— swelling, while intravenously it produces CNS
depression and hypotension.
7. Environmental factors and time of administration : Affect drug responses. Eg, Exposure to,
carcinogens, tobacco smoke and consumption of charcoal broiled meat are well known to induce drug
metabolism.
• Type of diet and temporal relation between drug ingestion and meals can alter drug absorption, e.g.
food interferes with absorption of ampicillin, but a fatty meal enhances absorption of griseofulvin and
lumefantrine.
• Subjective effects of a drug may be markedly influenced by the setup in which it is taken. Hypnotics
taken at night and in quiet, familiar surroundings may work more easily.
• Corticosteroids taken as a single morning dose cause less pituitary-adrenal suppression.

8. Psychological factor Efficacy of a drug can be affected by patient’s beliefs,
attitudes and expectations.
• Placebo This is an inert substance which is given in the garb of a medicine. It
works by psychodynamic rather than pharmacodynamics.
9. Pathological states Not only drugs modify disease processes, several diseases
can influence drug disposition and drug action:
Eg: Gastrointestinal (g.i.) diseases Certain g.i.diseases can alter absorption of
orally administered drugs. The changes are complex and drug absorption can increase or
decrease.
10. Other drugs: Drugs can modify the response to each other by
pharmacokinetic or pharmacodynamic interaction between them.

11. Cumulation Any drug will cumulate in the body if rate of administration is more than the rate of elimination.
12. Tolerance It refers to the requirement of higher dose of a drug to produce a given response. Loss of therapeutic
efficacy (e.g. of sulfonylureas in type 2 diabetes, or of β2 agonists in bronchial asthma), which is a form of tolerance.

LEGAL ASPECTS OF DRUG
THERAPY IN KENYA
Dr Joshua Meme

Section outline
• Acts of parliament controlling drug therapy in Kenya
• concept of essential drugs
• drug procurement process in Kenya

Section objectives
• Describe the Acts of parliament controlling drug therapy in Kenya
• Discuss the concept of essential drugs
• Explain the drug procurement process in Kenya

Acts of Parliament governing drugs
and drug use
• Pharmacy and poisons act Act. CAP 244
• Narcotics and Psychotropics Act No. 4 of 1994
• Dangerous drugs Act No. CAP 245, repealed to Act No. 21 of 1994
• Food Drugs And Chemical Substances Act CAP 245
• Public Health Act CAP 242,
• Health ACT No. 21 of 2017
• NACADA Act of 2012

Pharmaceutical Law
What is Pharmaceutical Law?
• Pharmaceutical Laws relate to the creation, sale, distribution, and use of
pharmaceutical drugs.
• These laws include intellectual property rights to protect drug manufacturers'
research, safety standards to protect the public from harmful side effects,
restrictions on marketing drugs to the public, and rules regarding how drugs may
be prescribed and distributed.
2/29/2024

Introduction….i
• Drugs can be used appropriately and inappropriately.
• Appropriate use of drugs: is for curative, preventive, palliative purposes among
others.
• Inappropriate use of drugs: any other use other than the legally intended
purpose.
• Legislation is vital to control and regulate the:
Production
Distribution
prescription
administration of drugs.
• Health professionals affected by statutes are the nurses, doctors, pharmacists,
clinical officers and pharmaceutical technologists.
• One must be familiar with regulations affecting drug use in ones area of practice.
You must abide by the drug control laws within your profession practice.

Pharmaceutical Law
Pharmaceutical Law also deals with the following aspects
►Drug production
►Drug sale
►Intellectual property
►Safety and marketing to protect the public from harmful side effects
►restrictions on marketing drugs to the public
►Issuing rules regarding how drugs may be prescribed and distributed.
2/29/2024

Introduction….ii
 There are two key acts of parliaments that control and regulate
drugs/poisons production: Distribution, prescription,
administration in Kenya they include
1. Pharmacy and Poisons Board Act, chapter 244 of 1989
2. Narcotics and Psychotropic substance (control) Act of 1994.

Pharmacy and poisons Act, Chapter 244 of
1989 Repealed 2012
• The act deals with the:
i. registration of pharmacists
ii. defines statutory poisons
iii. draws up statutory poisons list.
• This list is divided into two parts:
• Consist of poisons which are not to be sold except by authorized sellers of poisons and licensed
wholesale dealers and dealers in mining, agriculture or horticultural a accessories.
• Consist of poisons which are not sold except by persons entitled to sell part 1 poisons and by
persons licensed under section 32 of the poisons act of 1989 which sets out various schedules
which deal with the sale, labeling and color of certain poisons.

Narcotics and Psychotropic substance
(control) act of 1994
• This act gives schedules of controlled drugs which are regulated by the
act as:
• First schedules which is a list of narcotic drugs e.g. pethidine and
morphine
• Second schedule which is a list of psychotropic substances e.g.
clonazepam, diazepam, methylphenidate and pentobarbital
• Third schedule , which is list of prohibited plants, including cannabis, coca
bush and paupers somniferous

THE CONCEPT OF ESSENTIAL DRUGS
• Appeared in mid-1970s when there was inequitable distribution of resources for
health in developing countries. After a brief review of the drugs problems facing
developing countries at the world health assembly of 1975, the WHO Essential
drug program was born.
• It has provided a rational basis for drug procurement at national level and also
helped establish drugs requirements at various levels in the health care systems.
• Drugs, personnel are inadequate in developing countries especially rural areas.
The first list by WHO was drawn in 1977 but has been revised severally.
• Selection of essential drugs dependent on the specific country needs, hence the
list should be drawn locally and reviewed periodically.

Continuation……
• The concepts of essential drugs has been recognized as a useful tool for
selecting drugs according to needs and has provided a rational basis for drugs
procurement and for establishing drug procurements in national health care
systems.
• Essential drugs selected for any country are those which meet the health care
needs of the majority of the population. These drugs are supposed to be
available at all times in sufficient amounts and in the required dosages forms.

Some factors considered for selection
include...
• Epidemiological pattern of disease in the country
• Financial resources available for drugs in the country
• Availability of appropriate health care workers
• Efficacy and potency of drugs as shown by scientific
evidence

Categories of drugs according to the Kenya
essential drugs list (May,1993)
Comprises of the following :
• anesthetics
• analgesics
• antipyretics
• NSAISDs
• anti-allergy and drugs used in
anaphylaxis
• antidotes and substances used in
poisoning
•
• disinfectants & antiseptics
• diuretics
• gastrointestinal drugs
• hormones, endocrine drugs &
contraceptives
• immunologicals (vaccines)
• muscle relaxants

Continuation….
• antiepileptic; anti-infective drugs
• antimigraine
• antineoplastic and immunosuppressants
• antiparkinsonism drugs
• drugs affecting-see vitamins & minerals
• blood products and blood substitutes
• cardiovascular drugs; dermatological drugs
• diagnostic agents
• ophthalmological
• E.N.T preparations
• oxytocics and antioxytocics
• peritoneal dialysis solutions
• psychotherapeutic drugs
• respiratory tract drugs
• solutions for water ; electrolytes,& acid-base
balance disturbance
• vitamins and minerals

The drug procurement process in Kenya
• Drugs are expensive, taking up to 40% of the budget in some developing countries. To
minimize cost, competitive tendering system has been instated for both public and
private sectors. Tenders are only limited to registered products. Tendering is open to
local and international markets.
• The minimum conditions for bidding should be availability of the certificate of
pharmaceutical product provided by the exporting country as currently regulated by
the WHO “Certificate scheme on the Quality of Pharmaceutical Products Moving in
International Commerce”.

The drug procurement process in
Kenya…….continuation
• Procurement for private or public institutions is done preferably under the
supervision of a pharmacist who has the responsibility of ensuring effective
selection of the right products from numerous manufactures and suppliers.
• Purchase should be made from reputable and reliable sources to ensure that
clients get high quality supplies at lowest cost possible. In most of the East
African Countries, the supplies are inadequate and infrequent, hence there are
chronic shortages.
2/29/2024

Alternatives for the supply of drugs to both public
and private sector:
• Public sector drug supply which is currently done through
Kenya Medical supply Agency (KEMSA).
• Private –not- for profit systems e.g. through Mission for
Essential Drugs Supply (MEDS). This is often used by faith-
based healthcare institutions for their procurement of drugs.
• For-profit-systems. these are the retail pharmacies

2
2
• drug supply mgt involves four major functions:
– Drug selection
– Drug procurement
– Drug distribution and
– Drug use
• these are inter liked to each other & form acyclic
process

Thedrug mgtcycle
Selection
Druguse
Procurement
Drug
Distribution
ManagementSupportsystems
organization, financing,
information mgt & human
resource
Policy& legalframework
Lineof co-ordination
Flowof supply activity
2
2

2
2
• each major function build on the previousfunction
and leads logically to thenext
• the mgt support systemshold the drug mgtcycle
together in coordination
• drug QAis part of each and everyfunction

2
2
• mgt support systems– core
– organization - functional org’nalstructure
– financing and sustainability -adequate
– information mgt – reliable
– human resources mgt - motivatedstaff
• the entire framework relies on drug policies,laws
and regulations

2
2
Drug
Selection
• drug selection is aprocess of deciding the typeof
needed drug products for the prevalentdiseases
• involves:
– reviewing the prevalent healthproblems
– identifying t/ts ofchoice
– choosing individual drugs and dosage forms
• Factorsthat shouldbe consideredin selection:
– seethe formulary process

Drugprocurement
• drug procurement is the process of acquiring drug
products through purchase, manufacture or donation.
• an effective procurement process ensures the
availability of:
the rightdrugs
in the rightquantities
in the rightqualities
at the rightprice
at the righttime
from the rightsource

226
• procurement involves:
– quantifying drug requirements
– managing the tender process
– contracting for drugs andservices
– quality assurancefor procurements
– small scalelocal production and
– drug donations

Goodprocurement practice
227
1. Procurement by genericname
– often cheaper
– more informative & recognizable
– less risk of mistake, confusion & duplication
2. Procurement limited to EMLs
– avoid generic/brand duplications
– acquire safe, effective, cost- effectivedrugs

3. procurement inbulk
228
Good procurement…cont’d
– concentrate purchases on limited list toincrease
quality, reduceprice
4. formal suppliers qualification & monitoring
– approve suppliers before or aftertendering
– useaformal monitoring systemto ensure
continued supplier qualification

5. sol- sourcecommitment
229
– procurement should be from winningsupplier
6. order quantities based on reliable estimateat
actual need
– accurate estimates of order quantitiesare needed to
avoid stock outs or overstocks
– develop reliable consumption records & morbidity data
– adjust for past surpluses, shortages or stockouts
– adjust for expected program growth andchanging
diseasepatterns

7. separation of keyfunctions
230
• there are Severalkey procurement functions that required/t
expertise:
– drug selection
– drug quantification
– preparation of productspecification
– approval of supplier (pre orpost qualification)
– invitation for tender
• separation suchfunctions contributesto
professionalism & accountability
– leads to efficient procurement

8. transparency& writtenprocedure
231
• the tender process should betransparent
– make information on the tender process and results public
to the maximum extentpossible
• develop & follow written procedures forall
procurement actions

Procurement
cycle…cont’d
233
1. review drug selection
– identify what toprocure
– review the selected drugs each time you beginthe
procurement process
2. determine how much to procure
– Usethe d/t quantification methods

Procurement
cycle…cont’d
234
3. reconcile need and fund /budget
• compare total procurement cost with available
fund/budget
• if expected procurement cost exceedsfund athand,
userational methods of quantity adjustments
(VEN/ABC)
–omit the less essential items first

4. choose procurement method
235
Procurement cycle…cont’d
– usecompetitive methods for all butvery small or
emergency purchases

5. locate & select suppliers
236
– critical step
• selection of suppliers hasaprofound impact on
the quality and cost of drugsacquired

• common problems with unreliablesuppliers
– ineffective
– unsafe or even deadly drugs quality
– late deliveries
– complete default on confirmedorders
– lossesdue to poor packagingor
– lossesdue to short expirydates
cost
there should be pre- and post-qualification
procedures help to eliminate substandardsuppliers
237

238
• three waysof locating/selecting suppliers:
– direct inquiries
– advertisement of public tendersor
– contacts with other procurementorganizations
and international agencies

Procurement
cycle…cont’d
239
6. Specify contract terms
• Critical contract terms in drug procurementinclude:
– the specification of thedrug
– the quality standardsrequired
– language for the productlabel
– minimum information required on thelabel
– packaging standards
– the price and payment termsand
– the last day of shipment
– recall mechanism

7. prepare purchase order/requisition
240
– the purchase order is the drug requisition tobe
sent to the supplier
– make awritten request for everysupply
– arequisition form is an easyway to listthe
supplies that youneed
– the requisition form is used by the person who
orders the supplies and by the medical supplier
who fills the order and sendsthe supplies tothe
health facility

8. monitor order status
241
– using telephone, fax,E‐mails,etc
– monitor performance and compliancewith
contract terms by the suppliers

9. receive & check drugs
242
• assoon asthe drugs requested arrive:
– check for the type, quantities received againstthe
drug requisition & invoice (step7)
– check also the quality, packaging, labeling & shelf-
life

243
• if you find adiscrepancy in quality or quantity,
tell the person in charge and record it in writing
in discrepancy report form (2copies)
– return tosupplier
• common discrepancies include drugsand
supplies that are missing or over-issued,
expired, damagedor of poorquality

• When drugs are received, the followingsteps
should be taken:
– Checkthat the number of items receivedmatches
the number of itemsordered
Right item
Right unit size
Rightquantity
244

Procurement
cycle…cont’d
245
• check that all boxes/containers are sealed andintact

246
• when you finish checking the items inthe
delivery, sign the requisition form
• Keepthe form on file atyour facility
• put any damagedgoods or poor quality drugsin
abox to return to thesupplier
– return these supplies at the earliestopportunity

10. Store the supplies correctly and distribute the
drugs to where they are needed
247
– follow FEFOor FIFOprocedures
– FEFO means ―first-to-expire, first-out
– always distribute products that will expirebefore
other products
11. collect consumption information which can be
used to quantify next procurement quantity

Definition
“Essential drugs are those that satisfy the
health care needs of majority of population”

 Should available at all times
 In adequate amounts
 In the adequate dosage forms

History of the WHO Model List of Essential
Drugs
 1977 First Model list published, ± 200 active substances
 List is revised every two years by WHO Expert Committee
 Last essential drug list established in the year 2010

Great importance for developingcountries
 Development of treatment guidelines and national formularies
 Comprehensive national drug formulary
 Strategies to drug procurement and supply
 Drug financing and Drug donations
 Research priorities for drug use
 Drugs needed for specific disease

Guidelines for establishing anational programme for
essentialdrugs
 National drug regulatory authority should be established
 National drug and therapeutic committee (NDTC) should be
established
 Committee includes people from
Medical
Clinical Pharmacology
Pharmacy
Public health fields
Also from other appropriate health care fields

 Generic names should be used for all drugs
 Concise, accurate and comprehensive drug
information should be prepared
 Stability and bioavailability should be assured
 Efficient administration of supply, storage and
distribution of drugs
 Management of stocks and eliminate waste

Criteria for theselection
of essentialdrugs
 Pattern of prevalent disease and treatment facilities
 Level of training and experience of the personnel
 Financial resources available in the country
 Genetic, demographic and environmental factors
 Evidence based and not suituation based
 Selected drugs should have adequate data on their efficacy
and safety

 Performance of drugs in general has been proved in a
variety of medical setting
 Available in adequate quantities and in the dosage forms
that is recommended by NDTC
 Assured quality, stability and bioavailability
 Two or more drugs having same quality, stability and
bioavailability, choice on the basis of efficacy, safety,
quality, price and availability

 Cost , an issue; unit cost of drug alone should not be
considered. Cost of total treatment, cost/benefit ratio
should also be considered
 Comparative pharmacokinetic properties of drugs in
the same therapeutic category
 Local facilities to manufacture and storage also be
considered
 Should contain only single drug, combination
advantage over single drug in therapeutic effect, safety
and patient compliance

Selection of Pharmaceutical dosage forms
 General utility and wide availability of the dosage forms
 Tablets have wide acceptability and also cost effective
 Stability of dosage form under ambient climate conditions
 Established local preference
 Bioavailability and pharmacokinetics of dosage forms
 Selection of convenient dosage forms for selected population
Eg: Paediatric dosages, SR/CR dosage inclusion require
adequate documentation
Selection of specified salt form for a particular drug
Example: Chloramphenicol Palmitate, Amlodipine Besylate,
Erythromycin estolate

Quality Assurance and WHO certification scheme
 Should confirm with required standards of good
Manufacturing practice (GMP) and quality control
 Bioavailability of drugs
 Should confine International Pharmacopoeia and
its standards

Nomenclature
 Each pharmaceutical substance by a globally acceptable
generic name is importance
 International nonproprietory (INN) names becomes an
important arm of essential drug list and is almost globally
accepted
 INN periodically published by WHO for new addition of
pharmaceutical products
 Brought unifomity in the names of medicine
 Stop confusion and to ensure, safety of drugs for patients

Tasksafter the formationof
Essential druglist
 Updating the essential drug list
 Essential drug list for primary health care
centres
 Specialist control of drug use
 Research and development
 Drug information and education activities
 Making a list of reserve microbials
 Post registration drug studies

Updatingtheessentialdruglist-Continuousprocess
WHO guiding principles
 Must accomodate local situations to meet health needs of
majority of population
 Extent to which country establish EDL
 Guiding essential drug list by WHO is a contribution to solve
problems
 Need to include additional drugs for rare disease. Eg: TB drugs
in India
 Exclusion does not mean rejection
 Public health issue, epidemiological changes, new drugs
availability, progress in pharmacological and pharmaceutical
knowledge

Essential drug list forprimary
health carecentres
 Existing system of medicine
 National health infrastructure
 Pattern of endemic diseases
 Supplies

Specialist control of druguse
 Adequate specialist skills and complemaentary resources
needed before the introduction of new drugs. Examples of
situation requiring specialist control of drug use
· Use of reserve antibiotics for multiresistant bacteria
· Adequate regimen for TB and leprosy
· Use of antineoplastic, immunosupressive agent,
antiretrovial agent

Research anddevelopment
 Pharmaceutical aspects
▪ Development of drug procurement, drug
quality, processing, packaging and distribution
 Clinical and epidemiological aspect
▪ Toassess efficacy, safety, genetic and ethnic
difference
 Educational aspects
▪ Development of training programme

Drug information and educationactivities
 Develop formulary and drug information sheet on
all drugs in EDL
 Continual education programme on all aspects of
medical care, disease pattern, selection of
antimicrobials , diagnostic and other therapeutic
guidelines

Making a list ofreserve microbials
 Amoxicillin plus clavulianic acid
 Ceftriaxone
 Ceftazidine
 Vancomycin etc…

Post registration drugstudies
 Some drugs fail to produce benefit. Reasons are
▪ Clinical trial does not Iinclude groups like children, pregnant
women, old people
▪ Genetic and environment factors differs from population to
population
▪ Unexpected use of drugs, data on overdose not available
▪ Poor manufacturing practice
 Post registration drug studies help to estimate future demands,
quantify drug inventory, evaluate drug use

MUST
SCHOOL OF NURSING
PHARMACOLOGY II
DRUG DEPENDENCY

Drug dependency
Substance dependence, also known as drug dependence, is an adaptive state that
develops from repeated drug administration, and which results
in withdrawal symptoms such as sweating, vomiting or diarrhea Abstaining from
drug use can also trigger problems in mental functioning such as lack of focus,
depression or anxiety Upon cessation of drug use.
A drug addiction, a distinct concept from substance dependence, is defined
as compulsive, out-of-control drug use, despite negative consequences.
Drug addiction is a controversial and complex term that has different meaning to
different people
• addiction diagnosis indicates that an individual demonstrates a pattern of
behavior where acquiring & using a drug dominates his or her motivation. The
motivation to obtain and take the drug overwhelms the individual’s normal
protective constraints

• a drug is any substance, natural or artificial, other than food, that by its chemical
nature alters structure or function in the living organism and
• an addictive drug is a drug which is both rewarding and reinforcing.
• Recognizing you have a drug problem https://www.mayoclinic.org/diseases-
conditions/drug-addiction/symptoms-causes/syc-
20365112#:~:targetText=Drug%20addiction%2C%20also%20called%20substance,
nicotine%20also%20are%20considered%20drugs. Please follow the link to get
advice
• ΔFosB, a gene transcription factor, is now known to be a critical component and
common factor in the development of virtually all forms of behavioral and drug
addictions, but not dependence.
Drug dependency

Three basic processes
Tolerance
• Repeated exposure to the same dose of drug results in a lesser effect
• Body develops ways to compensate for the chemical imbalance caused by introducing
drug into the system
• Can be overcome by increasing the dose
Physical Dependence
• Depend on drug to function normally
• Occurrence of withdrawal syndrome when you stop taking drug abruptly
Vary from one class of drug to another
Compensating Mechanisms Produce Imbalance
Psychological Dependence
• Behavioral dependence
• High rate of drug use, craving for the drug & tendency to relapse after stopping use
• Related to drug reinforcing properties

Types of drug dependence
There are two main types of alcohol or drug dependence.
• The first kind is physical dependency. This means that the body has developed a
physiological reliance on a drug because it has caused changes in its natural state
of being. Opiates, tobacco, and alcohol are common drugs that cause physical
dependency.
• The second kind, psychological dependency, affects a person emotionally and
mentally rather than, or in addition to, physiologically. This develops from the
memory of the sense of euphoria that the drug creates, causing a person to long
for that feeling and think of it often. Cocaine and amphetamines are examples of
drugs that cause very serious psychological dependencies.
• Oftentimes, alcohol or drug dependency is due to a substance’s ability to
stimulate pleasure in the brain and produce a false overall sense of well-being.
• When users become addicted to this feeling, they crave whatever substance can
produce the feeling and abuse said substance.

Addiction
Addiction is a brain disorder characterized by compulsive engagement
in rewarding stimuli despite adverse consequences.
Despite the involvement of a number of psychosocial factors, a
biological process one which is induced by repeated exposure to an
addictive stimulus is the core pathology that drives the development
and maintenance of an addiction.
The two properties that characterize all addictive stimuli are that they
are reinforcing (i.e., they increase the likelihood that a person will seek
repeated exposure to them) and intrinsically rewarding (i.e., they are
perceived as being inherently positive, desirable, and pleasurable).

Addiction
Examples of drug and behavioral addictions include alcoholism, marijuana
addiction, amphetamine addiction, cocaine addiction, nicotine addiction, opioid
addiction, food addiction, video game addiction, gambling addiction, and sexual
addiction.
The only behavioral addiction recognized by the DSM-5 and the ICD-10 is
gambling addiction.
The term addiction is misused frequently to refer to other compulsive behaviors or
disorders, particularly dependence, in news media.
An important distinction between drug addiction and dependence is that drug
dependence is a disorder in which cessation of drug use results in an unpleasant
state of withdrawal, which can lead to further drug use.
Addiction is the compulsive use of a substance or performance of a behavior that is
independent of withdrawal. Addiction can occur in the absence of dependence,
and dependence can occur in the absence of addiction, although the two often
occur together.

Dependence syndrome
Definition
The Tenth Revision of the International Classification of Diseases and Health
Problems (ICD-10) defines the dependence syndrome as being
a cluster of physiological, behavioral, and cognitive phenomena in which
the use of a substance or a class of substances takes on a much higher
priority for a given individual than other behaviours that once had greater
value.
A central descriptive characteristic of the dependence syndrome is the desire
(often strong, sometimes overpowering) to take the psychoactive drugs
(which may or not have been medically prescribed), alcohol, or tobacco.
There may be evidence that return to substance use after a period of
abstinence leads to a more rapid reappearance of other features of the
syndrome than occurs with nondependent individuals.

Recognizing signs of drug use or intoxication:
marijuana, hashish and cannabis.
Signs and symptoms of drug use or intoxication may vary, depending on the type of
drug. Below you'll find several examples.
Marijuana, hashish and other cannabis-containing substances People use cannabis
by smoking, eating or inhaling a vaporized form of the drug.
Cannabis often precedes or is used along with other substances, such as alcohol or
illegal drugs, and is often the first drug tried.
Signs and symptoms of recent use can include:
• A sense of euphoria or feeling "high"
• A heightened sense of visual, auditory and taste perception
• Increased blood pressure and heart rate
• Red eyes
• Dry mouth

• Decreased coordination
• Difficulty concentrating or remembering
• Slowed reaction time
• Anxiety or paranoid thinking
• Cannabis odor on clothes or yellow fingertips
• Exaggerated cravings for certain foods at unusual times
• Long-term (chronic) use is often associated with:
• Decreased mental sharpness
• Poor performance at school or at work
• Reduced number of friends and interests
marijuana, hashish and cannabis.

K2, Spice and bath salts
Two groups of synthetic drugs synthetic cannabinoids and substituted or synthetic
cathinones are illegal in most states. The effects of these drugs can be dangerous
and unpredictable, as there is no quality control and some ingredients may not be
known.
Synthetic cannabinoids, also called K2 or Spice, are sprayed on dried herbs and
then smoked, but can be prepared as an herbal tea. Despite manufacturer claims,
these are chemical compounds rather than "natural" or harmless products.
These drugs can produce a "high" similar to marijuana and have become a popular
but dangerous alternative.

• A sense of euphoria or feeling "high"
• Elevated mood
• An altered sense of visual, auditory and taste perception
• Extreme anxiety or agitation
• Paranoia
• Hallucinations
• Increased heart rate and blood pressure or heart attack
• Vomiting
• Confusion

Substituted cathinones, also called "bath salts," are mind-altering (psychoactive)
substances similar to amphetamines such as ecstasy (MDMA) and cocaine.
Packages are often labeled as other products to avoid detection.
Despite the name, these are not bath products such as Epsom salts. Substituted
cathinones can be eaten, snorted, inhaled or injected and are highly addictive.
These drugs can cause severe intoxication, which results in dangerous health
effects or even death.
• Euphoria
• Increased sociability
• Increased energy and agitation
• Increased sex drive

• Increased heart rate and blood pressure
• Problems thinking clearly
• Loss of muscle control
• Paranoia
• Panic attacks
• Hallucinations
• Delirium
• Psychotic and violent behavior

Barbiturates, benzodiazepines and hypnotics
Barbiturates, benzodiazepines and hypnotics are prescription central nervous
system depressants.
They're often used and misused in search for a sense of relaxation or a desire to
"switch off" or forget stress-related thoughts or feelings.
Barbiturates. Examples include phenobarbital and secobarbital (Seconal).
Benzodiazepines. Examples include sedatives, such as diazepam (Valium),
alprazolam (Xanax), lorazepam (Ativan), clonazepam (Klonopin) and
chlordiazepoxide (Librium).
Hypnotics. Examples include prescription sleeping medications such as zolpidem
(Ambien, Intermezzo, others) and zaleplon (Sonata).

• Drowsiness
• Slurred speech
• Lack of coordination
• Irritability or changes in mood
• Problems concentrating or thinking clearly
• Memory problems
• Involuntary eye movements
• Lack of inhibition
• Slowed breathing and reduced blood pressure
• Falls or accidents
• Dizziness

Meth, cocaine and other stimulants
Stimulants include amphetamines, meth (methamphetamine), cocaine,
methylphenidate (Ritalin, Concerta, others) and amphetamine-dextroamphetamine
(Adderall, Adderall XR, others).
They are often used and misused in search of a "high," or to boost energy, to
improve performance at work or school, or to lose weight or control appetite.
• Feeling of exhilaration and excess confidence
• Increased alertness
• Increased energy and restlessness
• Behavior changes or aggression
• Rapid or rambling speech
• Dilated pupils

• Confusion, delusions and hallucinations
• Irritability, anxiety or paranoia
• Changes in heart rate, blood pressure and body temperature
• Nausea or vomiting with weight loss
• Impaired judgment
• Nasal congestion and damage to the mucous membrane of the nose (if snorting
drugs)
• Mouth sores, gum disease and tooth decay from smoking drugs ("meth mouth")
• Insomnia
• Depression as the drug wears off

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