It is a science that deals with the interaction of drugs with living systems. Pharmacology encompasses all aspects of knowledge about drugs including their composition, effects on the body, mechanisms of action, how the body processes drugs, and their applications. The key areas of pharmacology are pharmacodynamics, which is how drugs act on the body, and pharmacokinetics, which refers to how the body affects drugs. Pharmacology plays an important role in developing treatments and ensuring their safe and effective use in medicine.

1. Department of Pharmacology

2. • Pharmacology is the science of drugs
• In Greek, Pharmacon—drug; logos—study.
• In a broad sense, it deals with interaction of exogenously
administered chemical molecules with living systems or any single
chemical substance which can produce a biological response
• It encompasses all aspects of knowledge about drugs, but most
importantly those that are relevant to effective and safe use for
medicinal purposes

3. • For thousands of years most drugs were crude natural products of
unknown composition and limited efficacy.
• Only the overt effects of these substances on the body were rather
imprecisely known, but how the same were produced was entirely
unknown.
• Pharmacology as an experimental science was ushered by Rudolf
Buchheim who founded the first institute of pharmacology in 1847 in
Germany.
• In the later part of the 19th century, Oswald Schmiedeberg, regarded
as the ‘father of pharmacology’, together with his many disciples like J
Langley, T Frazer, P Ehrlich, AJ Clark, JJ Abel propounded some of the
fundamental concepts in pharmacology.
History

4. • Since then drugs have been purified, chemically characterized and a
vast variety of highly potent and selective new drugs have been
developed.
• The mechanism of action including molecular target of many drugs has
been elucidated.
• This has been possible due to prolific growth of pharmacology which
forms the backbone of rational therapeutics.

6. Scope

7. Pharmacodynamics (Greek: dynamis—power)
• 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
• For Example—Adrenaline → interaction with adrenoceptors → G-
protein mediated stimulation of cell membrane bound adenylyl cyclase
→ increased intracellular cyclic AMP → cardiac stimulation, hepatic
glycogenolysis and hyperglycaemia,

8. Pharmacokinetics (Greek: Kinesis—movement)
• What the body does to the drug.
• This refers to movement of the drug in and alteration of the drug by the
body; includes absorption, distribution, binding/localization/storage,
biotransformation and excretion of the drug
• For Example Paracetamol is rapidly and almost completely absorbed
orally attaining peak blood levels at 30–60 min; 25% bound to plasma
proteins, widely and almost uniformly distributed in the body (volume
of distribution ~ 1L/kg); extensively metabolized in the liver, primarily
by glucuronide and sulfate conjugation into inactive metabolites which
are excreted in urine; has a plasma half life (t½) of 2–3 hours and a
clearance value of 5 ml/kg/min.

9. Drug (French: Drogue—a dry herb)
• It is the single active chemical entity present in a medicine that is
used for diagnosis, prevention, treatment/cure of a disease.
Pharmacotherapeutics
• It is the application of pharmacological information together with
knowledge of the disease for its prevention, mitigation or cure.
• Selection of the most appropriate drug, dosage and duration of
treatment taking into account the specific features of a patient are a
part of pharmacotherapeutics.
Pharmacodynamic agents
• These are designed to have pharmacodynamic effects in the
recipient.

10. Clinical pharmacology
• It is the scientific study of drugs (both old and new) in humans.
• It includes pharmacodynamic and pharmacokinetic investigation in
healthy volunteers and in patients; evaluation of efficacy and safety
of drugs and comparative trials with other forms of treatment;
surveillance of patterns of drug use, adverse effects
Chemotherapy
• It is the treatment of systemic infection/malignancy with specific
drugs that have selective toxicity for the infecting organism/
malignant cell with no/minimal effects on the host cells.

11. Toxicology
• It is the study of poisonous effect of drugs and other chemicals
(household, environmental pollutant, industrial, agricultural,
homicidal) with emphasis on detection, prevention and treatment
of poisonings.
• It also includes the study of adverse effects of drugs, since the same
substance can be a drug or a poison, depending on the dose.

12. Tolerance
• It refers to the requirement of higher dose of a drug to produce a
given response.
• Loss of therapeutic efficacy
Tachyphylaxis (Tachy-fast, phylaxis-protection)
• It refers to rapid development of tolerance when doses of a drug
repeated in quick succession result in marked reduction in response.
Idiosyncrasy
• It is genetically determined abnormal reactivity to a chemical.
• The drug interacts with some unique feature of the individual, not
found in majority of subjects, and produces the uncharacteristic
reaction

13. Drug allergy (Drug hypersensitivity)
• It is an immunologically mediated reaction producing stereotype
symptoms which are unrelated to the pharmacodynamic profile of
the drug, generally occur even with much smaller doses and have a
different time course of onset and duration.
Drug dependence
• Drugs capable of altering mood and feelings are liable to repetitive
use to derive recreation, withdrawal from reality, social adjustment
Drug addiction
• It is a pattern of compulsive drug use characterized by overwhelming
involvement with the use of a drug.
• Procuring the drug and using it takes precedence over other activities

14. Receptors
• Specialized target macromolecules present on the cell surface or
intracellularly.
• The biological molecule plays a regulatory role.
• Drugs bind with receptors & initiate events leading to alterations
in biochemical activity of a cell, and consequently, the function of
an organ
Teratogenecity
• Abnormal foetus growth

15. Spare Receptors
• Receptors may be considered spare when the maximal response is
elicited by an agonist at a concentration that does not produce full
occupancy of the available receptors.
Agonist
• It is a medication that mimics the action of the signal ligand by
binding to and activating a receptor.
Antagonist
• It is a medication that typically binds to a receptor without
activating them, but instead, decreases the receptors ability to be
activated by other agonist.

20. Application of pharmacology
• To control speed of onset, intensity of the drug's effect, and duration of
action.
• Hence decide on route of administration, the amount and frequency of
each dose, and the dosing intervals.
• To identify the possible side effect and withdrawal symptoms of drugs
and take measures to manage.
• To avoid adverse effects from drug interaction and contraindicated
drugs.
• To avoid adverse effects in special populations like geriatrics,
paediatrics, pregnant and lactating mothers.
• To avoid treatment failure due to tolerance & resistance.
• To control misuse of drugs by the patient & health professionals.

21. Source of Drugs
1.Natural drugs
A. Plants
E.g. . Digoxin from Digitalis purpurea
Atropine from Atropa belladonna
Quinine from Cinchona officinalis
B. Animals
E.g.. Insulin from pork/beef
Cod liver oil from Cod fish liver.
C. Minerals: Iron, Iodine, Potassium salts.
D. Micro – organisms:
• Penicillin from Penicillium notatum, Chloramphenicol from
Streptomyces venezuelae (Actinomycetes).

22. 2. Synthetic drugs
• Prepared by chemical synthesis in pharmaceutical laboratories.
• E.g. Sulphonamides, quinolones, barbiturates.
3. Semi-synthetic drugs
• Prepared by chemical modification of natural drugs.
• E.g. . Ampicillin from penicillin G.
• Dihydroergotamine from ergotamine.
4. Biosynthetic drugs
• Prepared by cloning of human DNA in to the bacteria like E.coli.
• E.g.. Human insulin (humulin), human GH.

23. It is a science of drugs. It covers all aspects of knowledge of drugs.
Drug: Any substance or product that is used or intended, to be modify
or explore physiological systems or pathological states for the benefit of
the recipient.
.
Every drug has three of names
1. Chemical Name
2. Nonproprietary Name (Generic Name)
3. Proprietary name (Trade/Brand Name)

24. Chemical name
• These are given according to the chemical constitution of drug
Chemical
• Gives exact chemical composition of the drug
• Places atoms or molecular structure
• Nonproprietary name: (Official Name) It is assigned by the United
States Adopted Name (USAN) council. It is uniform all over world.
Generic Name
-Typically derived from chemical name
– Usually shorter.
Proprietary name
• It is given by the pharmaceutical manufacture

25. Trade Name
• Name registered by the manufacturer trademark symbol® only be used
by the single manufacturer
• Same drug May have several trade names (depending on number of
manufacturers)
• The first letter of the name is Capitalized
Chemical Name Non proprietary Trade Name
Acetyl
Salicyclic acid
ASPIRIN Disprin (India)
Bayer’s Asprin (USA)
Ecospirin (India)

26. Morphine preparation

27. Vinca rosea
Vinka alkaloids
Anti cancer
Digitalis purpurea
(foxglowe)
Digitalis
CHF
Cinchona pubescens
Quinine
Malaria
Rauwolfia serpentina (INDIA)
Reserpidine
Antihypertesive agent