The document provides an introduction to pharmacology and toxicology. It defines key terms like: - Pharmacology is the study of drugs and their effects and mechanisms of action in living systems. - Toxicology is the study of adverse health effects of chemicals. - Pharmacokinetics refers to how the body affects a drug while pharmacodynamics is what the drug does to the body. - Toxicants can enter the body through various routes and affect organs in both reversible and irreversible ways. Treatment involves removing unabsorbed toxins, administering antidotes, and promoting excretion of absorbed toxins.

1. Introduction to Syllabus
Presented by :
Ms. Jagruti Marathe

4. • Pharmacology is the science of drugs (Greek pharmakos,
medicine or drug; and logos, study
• Originating in the 19th century,
• The discipline makes drug development possible
• Pharmacology is one of the cornerstones of the drug
discovery process
• Pharmacology studies the effects of drugs and how they
exert their effects
Pharmacology

5. • Pharmacology
• Pharmacology is the science of drugs (Greek:
Pharmacon--d.rug; logos-discourse in) .
• In a broad sense, it deals with interaction of
exogenously administered chemical molecules
(drugs) with living systems.
• It encompasses all aspects of knowledge about drugs,
but most importantly those that are relevant to
effective and safe use for medicinal purposes

6. • The two main divisions of pharmacology are
pharmacodynamics and pharmacokinetics.
• 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 I
macromolecular levels,
• e.g.- Adrenalin…… 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, etc

7. • Pharmacokinetics (Greek: Kinesis-movement) - What the
body does to the drug. (ADME Studies)
• 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
• Eg : Paracetarnol 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
- lL/kg); extensively

8. • Thus, Amoxicillin cures a strep throat, and
• Cimetidine promotes the healing of duodenal
ulcers. Pharmacology asks “How”?
• The main tasks of pharmacologists are
• Screening for desired activity,
• Determining mode of action, and
• Quantifying drug activity

9. Toxicology
• Definitions
• Toxicological studies
• Dose-response correlations
• Threshold limit values
• Examples

10. Hazardous
• Denotes the probability of injury or illness
from contact or use
• Industrial Hazards
– Toxicity
– Explosivity
– Ignitability
– Reactivity

11. Toxicology
• Toxicology is the scientific study of adverse effects
that occur in living organisms due to chemicals. ...
• The substances that are assessed by toxicologists
includes environmental agents and chemical
compounds found in nature, as well as
pharmaceutical compounds that are synthesized for
medical use by humans.

12. Toxic Substance
• Capacity of a substance to produce injury or
illness
• Acute Effects
– Short term, appear shortly after exposure. Can be
from single exposure
• Chronic Effects
– There is a latency, long period of time before you
see effect

13. Three Types of Toxic Hazardous Materials
(Soures of toxicity)
• Chemical Agents (Poisons)
• Physical Agents (Dusts, fibers, heat, noise,
corrosive)
• Biological Agents (Pathogens)
Zoonotic diseases (Animals)

14. • 1. Animals : Venom, fungi, bacteria, shelfish
toxin,fish etc
• 2. Vegetables : Aconite, strychnine, Insulin
(Sugar)etc.
• 3. Chemicals : Drugs, HCN, Ethanol,
Chloroform, Lead, Argon etc.

15. Definitions
• Toxicology is the quantitative and qualitative
study of the adverse effects of toxicants on
biological organisms
• Toxicant is a chemical or physical agent that
produces adverse effects on biological
organisms.

16. So Toxicology is the study of:
• How toxicants enterthe organism
• How toxicants effect the organism
• How toxicants are eliminatedfrom (leave) the organism
All substances are toxic if taken in the wrong quantities

17. How toxicants enter organism
• Inhalation (mouth or nose to lungs) then into
blood(+*)
• Ingestion (mouth to stomach) then into blood(+)
• Injection (cuts, punctures in skin) into blood
• Dermal absorption (through skin) into
blood(+*)
+ Involve membrane transport
* Greatest threats in industry

18. Effects of Toxicants
Irreversible Effects
• Carcinogen - causes cancer
• Mutagen - causes chromosome damage
• Reproductive hazard - damage to reproductive
system
• Teratogen - causes birth defects

19. Effects of Toxicants
May or may not be reversible
• Dermatotoxic – affects skin
• Hemotoxic – affects blood
• Hepatotoxic – affects liver
• Nephrotoxic – affects kidneys
• Neurotoxic – affects nervous system
• Pulmonotoxic – affects lungs

20. Definitions
Pharmacology :the branch of medicine concerned with the
uses, effects, and modes of action of drugs
• Pharmacokinetics – the absorption, distribution, metabolism
and excretion (ADME) of chemicals through the (human)
system.
• Pharmacodynamic :is the study of how a drug affects an
organism,
• Bioaccumulation – things such as lead, mercury, PCBs, carbon
tetrachloride that build up in organs and have low excretion
rate.

21. Elimination of toxins
• Excretion through kidneys, liver and lungs
• Detoxification is the biotransformation of
chemicals into something less harmful

22. Toxicological Studies
• Aim:
• LD50 = Lethal dose 50 (Dose of drug at which 50 % Population
shows mortality)
• ED 50 = Effctive dose 50 (Dose of drug at which 50 %
Population shows pharmacological effect)
• To determine the therapeutic index, i.e. ratio between the
lethal dose and the pharmacologically effective dose in the
same strain and species (LD50/ED50).
• The greater the index, safer is the compound.
• The LD50 dose thus found was administered to guinea pigs,
rabbits, cats or dogs on weight basis (on basis of relative
surface area gives better results).
• To determine the absolute dose for a species

23. Pharmacological testing
• A. Preclinical studies ….Animal studies
• B. Clinical studies ……Human studies
Rodents : Strong
constantly growing
incisors and no
canine teeth

24. A. Preclinical
Criteria for evaluation of preclincal toxicological studies (Acute,
subacute & chronic toxicity studies)
Sr. No. Acute Subacute Chronic
01 Species Species Species
Rats preferred for oral and
inhalation tests;
rabbits preferred for
dermal tests
Rodents (usually rats) preferred for
oral and inhalation studies;
Rabbits--- for dermal studies;
non rodents (Usually dogs)
recommended as a second
species for oral tests.
Two species recommended;
rodent and non rodent (rats
& dog)
02 Age : Young adult Age : Young adult Age : Young adult
03 Number of animal :5 of
each sex (M/F) per dose
level
10 of each sex for rodents,
4 of each sex for non rodents
per dose level
20 of each sex for rodents,
4 of each sex for non
rodents per dose level

25. Sr. No. Acute Subacute Chronic
04 Dosage : Three dose levels
recommended; exposures
are singledoses or
fractionated doses up
to 24 hours for oral and
dermal studies; and 4 hour
exposure for inhalation
studies
Dosage : Three dose levels plus
a control group; include a toxic
dose level plus
NOAEL; exposure are 90 days
Dosage : Three dose levels
recommended; include a
toxic dose level and NOAEL;
exposures
generally for 12 months;
FDA requests 24 months for
food chemicals
05 Obseravation period Obseravation period Obseravation period
14 days 90 days (same as treatment
period)
12-24 months

26. Application of LD50
• It provides a measure of relative toxicities of chemical under
similar or identical conditions.
• Thus the major application of the LD50 is comparative,
allowing for semi quantitative toxic evaluation of compounds
• This test provides a screening method for toxic evaluation,
particularly useful for new unclassified substances.

27. • Dermal LD50
• Skin
• Eyes
• Mucosal surface
• Inhalation LD50

28. Dose Limit Values
• EDf – Effective dose for f
percent of population.
Reversible response
• TDf – Toxic dose for f
percent of population.
Undesirable response that
is irreversible
• LDf – Lethal dose for f
percent of population.

29. Definitions
• Therapeutic Margin
– TM = LD50% - ED50%
• Margin of Safety
– MOS = LD5% - ED95%
• Safety Index
– SI = LD5%/ED95%
• Therapeutic Index
– TI = LD50%/ED50%

30. Relative Toxicity Classification
Classification Human Oral LD50
Extremely Toxic Taste (1 grain)
Highly Toxic 1 tsp
Moderately Toxic 1 oz
Slightly Toxic 1 pt
Practically nontoxic 1 qt
Relatively harmless > 1 qt

31. Poison & Poisoning
A poison is any substance that is harmful to your body
Human poisoning could be suicidal, homicidal, stupefying
(shocking) or accidental.
Let us see each case in detail
a) Poison generally used for suicidal purpose are : potassium
cyanide, oxalic acid, hydrocynic acid, opium, barbiturates,
organophosphorus compound & arsenic
b) Poison used for homicidal purposes are : Arsenic, antimony,
aconite, organophosphoruscompounds, strychnine & Oleander
c) The poison used for stupefying purposes are: (Used to feel
properly) Dhatuta, Belladona, Hyoscyamus, cannabis indica &
cigarette conatining arsenic.
d) Accidental poisoning commonly occurs as a result of
carelessness with the poisonous & non-poisonous material are
stored together.

32. A number of case of accidental poisoning have been reported from the
greater use chemicals in industry & for household purposes.
Classification of poisons:
Poisons are classified according to their mode of action. Accordingly
poisons are classified in to three main groups viz:
1) Corrosive
2) Irritants
3) Neurotics
A. Corrosive : A corrosive poison is simply a highly active irritants
& not only produce irritation but also acute ulceration of tissue
Eg: a) Strong acid like sulphuric acid, nitric acid, hydrochloric acid
b) Organic acid like oxalic acid, carbolic acid
c) Conc. Alkalies like caustic soda, caustic potash & carbonates of
sodium, calcium & potassium.

33. 2. Irritants: Irritants poisons produce symptom of pain in the
abdomen, vomiting & purging.
Corrosive in dilute solutions acts as irritants, example of irritant are:
a) Inorganic: Non – metallic & metallic compounds
The non metallic poison are phosphorus, chlorine, bromine, iodine
& boron .
The metallic poisons consist of arsenic , antimony, mercury, silver,
iron, copper, bismuth lead.
b) Organic : The organic poison can be divided in to two types;
i) VEGETABLE poison &
ii) Animal poisons
Vegetable Poison Animal poison
Castor oil, castor seeds, croton oil,, colocynth,
ergot, marking nut & aloes
snakes, venom, scopions
venom & poisononous insect .
c) Mechanical : This group include powdered glass, chopped
hair, sponge & diamond dust

34. 3. Neuroleptics : These poisons primarily act on the CNS. The chief
symptoms of this type of poisoning includes hedache, drowsiness,
gidiness, delirium, stupor, coma & sometimes paralysis
The poisons in this group are classified as:
a) Poisons having specific action on cerebrum :
These poison may have a somniferous, inebriant or deliriant effect.
The somniferous poison include opium & its alkaloids.
The inebriant (intoxication) include alcohol, anasthetics, (ether,
chloroform) sedative & hypnotics (Chloral hydrate &
barbiturates) & insecticides (organophosphorus compound, coal
tar insecticide & naphthalene)
The deliriant (hallucinogen) ones include dhatura, belladona, &
cocaine.

35. b) Poisons acting peripherally: The poison acting on peripheral
nerves include conium & curare
C) Poisons acting on specifically spinal cord : This category include
nux vomica, & its alkaloids & gelsemium
Poisoning in the living could be divided in to:
a) Acute poisoning : Symptoms appear suddenly soon after
consumption of poison. The symptoms rapidly increases in
severity & are followed by death or recovery.
Poison can be detected in the ingested food, medicine of fluid or
vomit, urine or stool of the victim
C) Chronic poisoning : Symptoms develop more gradually. There is
an aggrevations of symptoms after the suspected food , medicines
or fluid is administered.
There is remission or even complete disappearance of symptoms
on the removal of patient from his usual surroundings.

36. The main symptoms in chronic poisoning are usually malaise,
chronic ill health & increasing cachexia (condition of abnormal
low body weight, weakness & general bodily decline).
Repeated attack of undiagnosed gastrointestinal irritation
should arouse suspicion of homicidal poisoning.

37. General Treatment of Poisoning
The main aim of treatment is to help the patient to stay alive by
attention to respiration & circulation while he is encouraged to
get rid of his by metabolism or excretion.
The step involved in treatment of a case of poisoning are:
1) Removal of unabsorbed poison from the system
2) Use of antidote
3) Elimination of absorbed poison
4) Treatment of general symptoms &
5) Maintenance of the patients general condition

38. 1. Removal of the unabsorbed poison from the system
a) For inhaled poisons: When a poison like carbon monoxide are or
a gas from septic tank is inhaled by patient,
*he must be immediately removed to fresh air.
*Artificial respiration must be given
a) For injected poisons: If a poison has been injected torniquets
must be applied proximal to the point of application. Unabsorbed
poison can be removed by means of incision & suction.
b) Contact poison : If poison is split & sprayed on skin,eye, or
wound,or be inserted to vagina , rectum or bladder ,
It must be washed with plain water.
If specific antidote is known, it can be neutralised with it.
a) Ingested poison : The most important thing is to remove the
ingested poison . It can be through about by vomiting &/or by
washing the stomach (Gastric lavage)

39. Emetics can be used to bring about vomiting .
Simple means; such as copious draughts of warm water,
Mustard powder (2-3 teaspoonful) or
Salt (3 level teaspoonful) in a glass full of water can be used.
Ipecac 1-2 g or sulphate 1-2 g in 200 ml of water or
Ammonium carbonate 1-2 g dissolved in water can also be used.
Apomorphine in dose of 6 mg given subcutaneously causes prompt
vomiting.
It must not be used frequently as it is a respiratory depressant.
Vomiting is contraindicated in cases of acid or alkali
poisoning as it may cause rupture of the stomach in cases of coma
as in this case there is a risk of the poisoning entering the bronchial
tree.
Gastric lavage is the best method for it can be undertaken about 4 to
6 hrs after the ingestion of poison.

40. GASTRIC LAVAGE : The method to perform this is : the
patient should be prone or semiprone on his side with hips
higher than his head, as this will aid respiratory drainage . The
stomach tube must be passed inside though the mouth.
After checking that the tube is not in the trachea, most of the stomach content
should be removed first by mechanical suction if available.
After this first washing of the stomach is done with warm
water. The process is repeated either with warm water or the
antidote until the returning fluid clear
When the poison has been removed , some of the
antidote or either suitable solution may be left in the stomach.
(The useful solutions for this purpose are magnesium sulphate or sodium sulphate to
ensure purgation of any poison that has passed the intestine activated charcoal to
absorb alkaloid & liquid paraffin as a demulcent fluid)

41. Antidote :
An antidote is a substance that can counteract a form of
poisoning.
Antidote are classified as:
1) Mechanical
2) Chemical
3) Systemic
4) Universal

42. 1) Mechanical antidote : These are the substance which hinder the
absorption of poison by their mere presence
Eg: a) Fats, oils, egg, albumin.
These act by forming coat cover over mucous membrane of stomach
b) Charcoal is specifically useful in absorbing alkaloidal poisons
2) Chemical antidote : These substance react with poison to form non –
toxic substances Eg:
a) Magnessium oxide calcium oxide neutralizes acids.
b) Tannis forms insoluble complexes with most of the alkaloids.
3) Systemic antidote: They produce the action which are opposite to
that of poison
Eg: Chloroform for strychnine
Caffeine for morphine etc.
*Demerits : The antagonism is not always complete & the remedy
may itself produce most undesirable effect.

43. Certain chelating agents are widely used as specific antidotes against
some heavy metals.
These compound forms stable, soluble non toxic complexes with
heavy metals.
Eg: BAL, EDTA & Versenate (Calcium diethyl tetra acetate) for
arsenic EDTA &
Versenate for mercury & lead ,
N-penicillamine for lead, mercury & copper &
desferroxamine – B (D-F- M)- for iron.
BAL : (Dimercaprol): (British Anti-lewisite)
Most of the enzyme in the body have –SH groups, which are essential for
their activity.
Many heavy metals like arsenic & mercury have great affinity for these
groups.
Thus, after combining with these –SH groups these compounds reactivate
them.
BAL has many-SH groups, which combine with these heavy metals.

44. Leaving the –SH group of enzyme of body free.
The compound formed by the heavy metal & the di-thiol, dimercaprol
is relatively stable & is excreted without causing damage to the
excreting mechanism (Kidney, liver etc.)
BAL is given IM as 5 % solution in arachis oil with benzyl benzoate.
In severe poisoning a dose of 3mg/kg is administered at 4 hourly
interval for the first 2 days , at 6 hourly intervals there after for about
10 days.
Sodium calcium EDTA: It has great affinity for lead.
Therefore, it is now used in poisoning caused by inorganic lead &
tetraethyl lead.
Short causes of treatment are advised in order to minimize the danger of
depleting the body of metallic ions essential for metabolism. The usual
dose is 1g twice daily for periods up to 5days. After an interval of 2
days this course of treatment may be repeated.
EDTA can also be used in poisoning by arsenic & mercury

45. Universal antidote:
It is used as an antidote in cases of where the nature of the poison
is not known or a combination of poison are administered.
It consist of
Sr.No Ingredient Quantity Uses
1 Powdered charcoal 2 parts Adsorb alkaloids
2 Magnessium oxide 1 parts Neutralises acids
3 Tannic acid 1 parts Precipitates alkaloids
The mixture is administered in the doses of
tablespoonful , repeated once or twice.

46. 5) Elimination of absorbed poison: Elimination by catharsis
(removal) may be encouraged.
A) Forced diuresis
B) Peritoneal dialysis
C) Haemodyalysis
A) Forced diuresis using IV (Intravenously)
Chlorthiazides or mannitol infusion is useful in
Barbiturate poisoning.
B) Peritoneal dialysis (Peritoneal dialysis (PD) is a treatment that
uses the lining of your abdomen (belly area), called your peritoneum,
and a cleaning solution called dialysate to clean your blood.
Dialysate )
is useful in salicylate poisoning.

47. C) Haemodyalysis (Haemodialysis is a way of cleansing the blood
of toxins, extra salt and fluids through a dialysis machine)
has been employed for removing barbitutes, boric acid, bromides,
glutethimide, salicylates etc.
6) Treatment of general symptoms: Morphine (Centrally acting
analgesic, opioid analgesic, steroidal antinflamatory drug) should
be given for pain,
Oxygen for respiratory failure,
Cardiac stimulant failing particular symptomatic effect of the poison.
7) Maintenance of patients general condition: The patient should
be kept warm & comfortable. In cases of poisoning especially in
elderly (Geriatric) patient there is a possibility of upper respiratory
tract infections. To avoid this prophylactic administration of
antibiotics in all cases is desirable.

48. Thank you.