1. Pharmacology is the study of drugs and their interaction with biological systems. It has two main divisions: pharmacokinetics, which is what the body does to the drug, and pharmacodynamics, which is what the drug does to the body. 2. Therapeutic index refers to the margin of safety of a drug, calculated as the ratio of lethal dose to effective dose. A higher therapeutic index indicates a drug is safer. 3. Pharmacotherapeutics is the study of drugs used for treatment of diseases. Chemotherapy refers specifically to treatment of infections using chemical agents. Toxicology studies adverse effects of drugs and methods of detection, prevention and treatment of poisoning.

1. Lecture No. 01
Chapter
01
▪ By
▪ Mr. Sagar K. Gangurde
▪ M. Pharm (Pharmacology)
▪ SGSS College of Pharmacy, Manur, Kalwan

2. `

3. The word Pharmacology is derived from Greek word-
“Pharmakon” means Drugs.
“Logos” means To study/ Science.
Hence,
Pharmacology is the science of drug.
In broad sense,
It is the branch of science deals with the study of interaction of drug
with biological system.
Eg. Paracetamol used to reduce elevated body temperature.

4. Pharmacology is an experimental science was ushered by Rudolf Buchheim
who founded the first institute of pharmacology in 1847 in Germany.
Oswald Schmiedeberg regarded as the “Father of Pharmacology”

5. Two main divisions are there: -
1. Pharmacokinetics : - (Movement of drug)
- What the body does to the drug?
2. Pharmacodynamics : - (Power/ Action of drug)
- What the drug does to the body?
Physiology: - It means study of functions of human body.
Disease: - Any physiological or psychological disturbances called Disease.
Drug: - An agent or substance used for diagnosis, prevention, mitigation, cure or treatment of disease or disorder called Drug.
Dose: - It is the minimum effective concentration of drug when administered to the patient, it shows desired response without
producing adverse effect. OR the amount of drug require to produce therapeutic effect is called Dose.

6. Pharmacokinetics: -
It is the branch of pharmacology deals with study of Absorption, distribution,
metabolism and excretion of drugs called Pharmacokinetics.
For ex,
Tab. Paracetamol
Rapidly absorbed orally
Attaining peak blood levels at 30-60 min
25% bound to plasma proteins
Widely and uniformly distributed in body
Metabolized in liver
Excreted in Urine

7. Pharmacodynamics: -
It is the branch of pharmacology deals with study of mechanism of
action (MOA) & pharmacological action of drugs called Pharmacodynamics.
For ex,
Barbiturate (Sedative & Hypnotic drug)
Acts on Picrotoxin site of BZD receptor
Increases the Chloride ion conductance by opening of chloride channel
Produces sedative/hypnotic action

8. Therapeutic Index: -
It means Margin of Safety. Most of drugs are like double-edge swords. At recommended dose they shows or gives desired
clinical effects. However at higher dose they are toxic or poisonous.
It is necessary to express the potency and/or toxicity of drug to establish the safety of drug.
So the therapeutic index is the ratio of Lethal dose and Effective dose and it indicates the relative margin of safety of drug.
Hence,
Therapeutic Index = LD50 Drug dose at which it shows toxic effect or cause death after its administration in 50% of the population groups
ED50 Drug dose at which it shows therapeutic effect after its administration in 50% of the population groups
The larger the difference between lethal doses & effective doses then larger the TI and the drug will
safer to use which requires less therapeutic drug monitoring (TDM).
The smaller the difference between the doses then smaller the TI and the drug is more dangerous
which needs greater TDM. For Ex., Sedatives & Hypnotics. Barbiturate at low dose shows sedative
effect but at higher dose it shows toxic effect like coma or may death.

9. Therapeutics: -
In Greek it means art of medicines.
It deals with the different measures used to treat different diseases called Therapeutics.
For ex.,
Physiotherapy, Psychotherapy, Radiotherapy, Pharmacotherapy.
Pharmacotherapeutics: -
The study of drugs in relation to their application in the treatment of disease is known as Pharmacotherapeutics.
The use of drug in the treatment of diseases the branch called as Pharmacotherapeutics.
For Ex., Aspirin & Paracetamol used to treat headache or fever.
Chemotherapy: -
The chemical agents (Drug) used in the treatment of different infectious diseases is called Chemotherapy. It treats
systemic or local infections by destroying causative organism without destroying host’s cells.
For Ex., Tuberculosis – Rifampicin, HIV – Zidovudine, Herpes Zoster – Acyclovir….etc.

10. Toxicology: -
It is the branch of science deals with the study of poisonous effect of drugs and other chemicals like household,
environmental pollutant, industrial etc. with their method of detection, prevention and treatment.
It also study of adverse effect of drugs. The same substance can be a drug or poison depending on the dose.
Sources of Drugs: - Nature of Drugs: -
Sources of Drugs Examples
Plant Source Morphine, Quinine etc.
Animal Source Insulin, Heparin, Thyroid extract
Mineral Liquid Paraffin, Kaolin, Talc
Synthetic Aspirin, Paracetamol
Microorganisms Penicillin, Streptomycin etc.
Nature of Drugs Examples
Alkaloid Morphine, atropine
Glycosides Digitalis
Fixed Oil Peanut oil, Coconut oil
Volatile oil Peppermint, Cinnamon
Gums, Tincture Agar, Catechu tincture