This document provides definitions and introductions to key concepts in pharmacology. It defines pharmacology as the study of drugs, including their sources, properties, uses, and effects on living organisms. A drug is defined as any chemical substance that affects living processes. Drugs are categorized as over-the-counter or prescription. Prototype drugs are original drugs from which other drugs in a class are developed. Orphan drugs treat rare diseases. Essential drugs satisfy most health needs. Drugs have chemical, non-proprietary, and proprietary names. Pharmacopoeias and formularies describe commonly used drugs. Pharmacology has dynamics and kinetics divisions concerning drug effects and movement in the body. Clinical, experimental, epidemiological, economic

1. DR. SWETABH VERMA
PG-1ST YEAR
DEPT OF PHARMACOLOGY
INTRODUCTION TO
PHARMACOLOGY

2. Definition of Pharmacology
 "The subject of pharmacology is a broad one and embraces the
knowledge of the source, physical and chemical properties,
compounding, physiological actions, absorption, fate, and excretion,
and therapeutic uses of drugs.
 Pharmacology is a branch of medicine which deals with drugs
 Pharmacon – drugs
 Logos – studies

3. DRUG
 French: Drogue—a dry herb
 A drug may be broadly defined as any chemical agent that
affects living protoplasm, and few substances would escape
inclusion by this definition.
 WHO defines “a drug is a chemical substance or
biological product that is used or intended to be used to
modify or explore physiological systems or
pathological states for the benefit of the recipient”

4. Drug (Contd.)
 It is a chemical substance that affects processes in living organism
& used for prophylaxis (prevention), treatment, diagnosis or
cure of the disease in human beings or animals.
 Any single chemical substance which can produce a biological
response is a drug.
 Drug is called medicine when used in proper dosage form for safe
administration.
 All medicines are drugs but all drugs are not medicines.

5. Drug(Contd)
 Drugs in general, can thus be divided into:
 Pharmacodynamic agents- These are designed to have
pharmacodynamic effects in the recipient.
 Chemotherapeutic agents- These are designed to inhibit/kill
invading parasite/malignant cell and have no/minimal
pharmacodynamic effects in the recipient.

6. DRUG CATEGORIES
 OTC drugs - safe drugs and can be sold Over The
Counter by chemist without prescription
 eg- vitamins, antacids, paracetamol etc.
 Presciption drugs – drugs used under medical
supervision and dispensed by an order of a RMP.
 eg- antibiotics, antidepressants, narcotics etc.

7. PROTOTYPE DRUG
 Original or most commonly used drug belonging to a pharmacological
group.
 It is usually the Parental Drug from which other drugs were
developed.
 For an easy recognition of the drugs belonging to a particular group
and to correlate their pharmacological effects.
 e.g.- XYLOCAINE is a prototype drug for LA,
MORPHINE is a prototype drug for analgesics

8. Orphan Drugs
 When a drug is not developed into a usable medicine because the costs
will not be recovered by the developer then it is known as orphan
drug & the disease is an orphan disease.
 Orphan drugs are those which are used for treatment, prevention
or diagnosis of rare diseases like Kalazar, Cancers, Viral diseases,
Heavy metal Poisoning.

9. Essential Drug Concept
 WHO 1977
 Essential drugs are those drugs which satisfy health care
needs of the majority of the population, be available
at all times in adequate amounts, in appropriate
dosage forms and at reasonable cost.

10. DRUG NOMENCLATURE
A drug generally has three categories of names:
 Chemical name - It describes the substance chemically,
e.g.1-(Isopropylamino)-3-(1-naphthyloxy)propan-2-ol for propranolol.
This is cumbersome and not suitable for use in prescribing.
 Non-proprietary name - It is the name accepted by a competent
scientific body/authority,
e.g.the United States Adopted Name (USAN) by the USAN council.

11. DRUG NOMENCLATURE (contd.)
 The non proprietary names of newer drugs are kept uniform by an
agreement to use the recommended international nonproprietary
name (RINN) in all member countries of the WHO.
 Many older drugs still have more than one non-proprietary names,
 E.G. ‘Meperidine’ and ‘pethidine’ or ‘lidocaine’ and ‘lignocaine’ for
the same drugs.
 Until the drug is included in a pharmacopoeia, the nonproprietary
name may also be called the approved name.

12. DRUG NOMENCLATURE (contd.)
 Proprietary (Brand) name- It is the name assigned
by the manufacturer(s) and is his property or trade mark.
 One drug may have multiple proprietary names, e.g.
ALTOL, ATCARDIL, ATECOR, ATEN, BETACARD,
LONOL, TENOLOL, TENORMIN for atenolol from
different manufacturers.

13.  Brand names are designed to be catchy, short, easy to
remember and often suggestive.
 There are many arguments for using the non proprietary
name in prescribing: uniformity, convenience, economy
and better comprehension.

14. DRUG COMPENDIA
Pharmacopoeia
 An official book published by authorized body in a country containing
description of commonly used drugs with their sources, properties, uses,
doses, purity and potency.
 They are useful to drug manufacturers and regulatory authorities, but not
to doctors.
 It is revised every five years.
 Drugs contained in pharmacopoeia are official drugs.
I.P. – Indian pharmacopoeia.
B.P. – British pharmacopoeia.
U.S.P. – United states pharmacopoeia

15. DRUG COMPENDIA(Contd.)
Formularies
 Easily carried booklet form
 They list indications, dose, dosage forms, contraindications,
precautions, adverse effects and storage of selected drugs that are available
for medicinal use in a country.
 Drugs are categorized by their therapeutic class.
 Brief guidelines for treatment of selected conditions are provided
 British National Formulary (BNF)
 National Formulary of India (NFI)

16. Divisions Of Pharmacology
The two main divisions of pharmacology are
 PHARMACODYNAMICS
 PHARMACOKINETICS

17. Pharmacodynamics
 Dynamis means Power
 Pharmacodynamics can be defined as the study of the
biochemical & physiological effects of drugs & their
mechanism of action at organ system/ subcellular/
macromolecular levels.
 It is what the Drug does to the body
 Qualitative aspects: Receptors, Enzymes, Selectivity
 Quantitative aspects: Dose response, Potency,
Therapeutic efficacy, Tolerance

18. Pharmacokinetics
 Kinesis means movement
 Absorption
 Distribution
 Metabolism/ Biotransformation
 Excretion
 It is what The body does to the drug
 Time course of drug concentration; Order of reaction; Plasma half-life
& steady state concentration; Therapeutic drug monitoring.
 Drug dosage & dosing schedules

19. Definitions
 Clinical Pharmacology deals with the study of drug effects
in humans beings, i.e. healthy volunteers and patients.
 The aim of clinical pharmacology is to generate data for
optimum use of drugs and the practice of ‘evidence based
medicine’.
 Experimental Pharmacology deals with the study of drug
effects in laboratory animals.
In vitro – Isolated tissue.
In vivo – Intact organism.

20. Definitions(Contd…2)
 Pharmacoepidemiology - study of the use & effects of
drugs in large number of people. It helps to gain further
insight into the efficacy & safety of new drugs after they
are released for community use.
 Pharmacoeconomics - study of the cost-effectiveness
of drug treatments; it analysis the cost benefit ratio of the
individual health care measures.

21. Definitions(Contd…3)
 Pharmacogenomics- The science that examines
the inherited variations in genes that dictate the drug
response of humans.
 Pharmacovigilance- The process of identifying &
responding to the issues of drug safety.
 WHO suggests that every country should set up a
pharmacovigilance centre & adverse drug reactions of any new
drug should be shared globally.

22. Definitions(Contd…4)
 Pharmacotherapeutics - It is the application of
pharmacological information together with knowledge of
the disease for its prevention, mitigation or cure.
 Part Of Pharmacotherapeutics
1. Selection of the most appropriate drug and dosage
2. Duration of treatment
3. Specific features of a patient

23. Definitions(Contd…5)
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.

24. Definitions(Contd…6)
Pharmacy is the manufacturing, compounding and
dispensing of drugs in suitable dosage forms for
administration to human being or animal.
Two types—
1. Extemporaneous Pharmacy -it comprises the preparation of
drugs and formulae prescribed by registered medical practitioners.
2. Official Pharmacy -it comprises the preparation of drugs and
formulae according to the processes recognized by or prescribed in
official pharmacopeia.

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