1.1 Introduction and basic terminologies of pharmacology.

A. Introduction to pharmacology:

Pharmacology: It is a science of drug or study of drugs action (Greek

word Pharmakon- drugs; logos- study).

Pharmacology is the branch of science which deals with the study of drugs. It
consists of detail study of drugs, particularly their action on living animals, organs
or tissues. The action may be beneficial or harmful.

Basically, pharmacology deals with how drug interact within biological system to
affect function. It is the study of drug, of the body reaction to drugs, source of
drug, their nature, and their properties. It encompasses all aspect of knowledge
about the drugs, but most importantly those that are relevant to effective and safe
use for medicinal purpose.

Scope of Pharmacology

❖ Scientific understanding of drugs enables us to predict the pharmacological

effect of a new chemical that will produce a specified therapeutic effect.
❖ Incorporate many new approaches such as computer-assisted drug design,
genetic screens, protein engineering and use of novel drug delivery vehicle
including virus and artificial cells.
❖ Our society needs pharmacologist who understands the basis of modern
therapeutics for careers within academics, pharmaceutical and governmental
laboratories to study and develop tomorrow’s drugs.

B. Basic terminologies of pharmacology

o Drugs: Drug is any chemical substance that, when absorbed into

the body of living organism, alter normal body function.
According to WHO “A drug is any substance or product that is
used or is intended to be used to modify or explore physiological
system or pathological state for the benefit of the recipient”.

o Pharmacy: It is an art and science of compounding or dispensing

and preparation of suitable dosage forms which involves
 collection, identification, purification, synthesis, and
standardization and quality control procedures.

o Medicine: Medicine is a drug or remedy used in prevention and

treatment of disease. All drugs are medicine but all medicine are
not of drug.

o Pharmaceuticals: The drug and related product is called

Pharmaceuticals.

o Pharmacotherapeutics: It is the application of pharmacological

information together with knowledge of the disease for its
prevention, mitigation or cure.

o Clinical pharmacology: Clinical pharmacology is the scientific

study of drugs in man. Its objective is to optimize drug therapy.

o Poison: Poison is any substance which endangers life by severely

affecting one or more vital functions.

o Toxicology: It is the study poisonous effect of drugs and other

chemicals with emphasis on detection, prevention and treatment of
poisoning.

o Active pharmaceutical ingredient (API): It is the main or active

chemical substance used to make a drug dosage form.

o Excipients: The chemicals or ingredients other than API used

during manufacturing of drug dosage form are called excipients.

o Crude drug: The drugs derived from the natural materials such as
plants, animals, minerals etc. are called crude drugs.
o Therapeutics: It is a branch of medicine concerned with the cure
of disease or relief of symptoms and includes drug treatment.

o Therapy: It is the method of treatment of disease by various

methods. E.g.
• Physiotherapy- treatment by physical exercise
• Radiotherapy- treatment by radiation
• Chemotherapy- treatment by chemicals
o Dose: Dose is an appropriate amount of drugs needed to produce
certain degree of response in patient.

o Indication: Disease or condition on which certain drug can be

used. E.g. Paracetamol is indicated in fever.

o Contraindication (contra: opposed to): Disease or condition on

which certain drug cannot be used. E.g. Paracetamol is
contraindicated in liver disease.

o Adverse drug reaction (ADR): It is an unwanted and undesirable

effect of drug action.

o Mechanism of action (MOA): It means how drug produces its

action in the body.

o Precaution: It refers to care to be taken while using certain drug.

o Side effect: Side effects are pharmacological effects produced with

therapeutic doses of the drug. E.g. Atropine is used as
preanesthetic medication for its antisecretary action, produces
dryness of mouth as a side effect.

o Drug Interaction: If the effect of one drug is altered by

concurrent administration of another drug or certain food then it
 refers to drug interaction. E.g. effect of Aspirin is altered by
Antacid.

o Teratogens: Some drugs when given in the pregnancy may cause

fetal abnormalities and are said to be teratogens. The effect is
called teratogenic effect and the process is called teratogenesis.
E.g. absent or abnormal due to thalidomide.

o Agonist: Agonist is a drug or agent which initiates a

pharmacological action after combining or binding with specific
receptor.

o Antagonist: Antagonist is a drug or agent which inhibits or

diminishes the pharmacological action after combining or binding
with specific receptor.

o Synergistic effect: When the action of one drug is facilitated or

increase by the other then they are said to be synergism and the
effect is called synergistic effect.

o Addiction: This is the condition on which patient become physical

or psychological depend on certain drugs. E.g. long term use of
diazepam, codeine, morphine etc. causes addiction.

o Hypersensitivity: This refers to minor to severe allergic reaction

due to certain drug. E.g. anaphylactic shock due to penicillin.

o Prophylactic agent (Prophylaxis): These are used for the

prevention or protection from a susceptible disease. E.g.
Chloroquine is taken 2 weeks before going to malarial affected
area.

o Sterilization: It is the process of making an object or intruments

free from microorganism and their spores.
o Manufacturing date: It is the date on which certain drug is
prepared and packed. E.g. Jan 2020

o Expiry date: It is the date on which the potency and stability of a

drug is decreased.

o Packaging: It is the covering of drug that protects a drug from

contamination and ease for handling. E.g. tablet and capsule in
strip or blister packing, liquid drugs in a glass or plastic bottle
packing.

o Placebo: Any component which is used to benefit or please the

patient, not by pharmacological action but for psychological
reason.

o Pharmacovigilance: It is a pharmacological science relating to

the collection, assessment, monitoring and prevention of ADR.

o Pharmacopoeia: An official code containing a selected list of the

established drugs and medical preparations with descriptions of
their physical properties and tests for their identity, purity and
potency. E.g. Indian Pharmacopoeia (IP), British Pharmacopoeia
(BP).

o Prescription: It is an order of medication issued by a medically

licensed Physician to the Pharmacist for dispensing.

o Essential Drugs: Essential drugs are those drugs that satisfy the
health care needs of the majority of population; therefore they
should be available at any time and at a reasonable price.
 o Pharmacodynamics: It refers to what drug does to body. It
involves physiological and biological changes that occur after drug
administration and their mechanism of action at organ system / sub
cellular or macromolecule level.

o Pharmacokinetics: It refers to what body does to drugs. It refers

to movement of the drug in and alteration of the drug by the body
which includes absorption, distribution, metabolism and excretion

1.2 Discus nomenclature and sources of drug.

A. Drug nomenclature:
Drug nomenclature is the systematic naming of drugs,
especially pharmaceutical drugs. In the majority of circumstances, drug has 3
types of names;
1. Chemical name: It is based on chemical structure of the drug. There are
various system of chemical nomenclature, the most important is the
IUPAC name. Chemical names are typically very long and too complex to
be used.
E.g.1-(Isopropylamine)-3- (1-naphthloxy) propan-2-ol’ is a chemical
name of propranolol
2. Non- proprietary (generic) name: It is the short name given to a drug in
Agreement with the originally manufacturer and the US adopted Names
Council. It is officially recognized worldwide.
3. Propriety (brand/ trade) name: It is the trademark name to a particular
drug, assigned by the pharmaceutical company. No other manufacturer
can legally use this name for their version of the drug.
Chemical name: 1-(Isopropylamine)-3- (1-naphthloxy) propan-2-ol’
Generic name: Propranolol
Brand name : Minil

B. Sources of drugs:
They are natural, semisynthetic and synthetic.
Natural sources are plants, animals, minerals, microorganisms, etc. ,
semisynthetic drugs are obtained from natural sources and are later
chemically modified. Synthetic drugs are produced artificially.
The different sources of drugs are:
1. Plants:
a. Alkaloids, e.g. morphine, atropine, quinine, reserpine,
ephedrine
b. Glycosides, e.g. digoxin, digitoxin.
2. Animals: Insulin, heparin, antitoxin sera
3. Minerals: Ferrous sulphate, magnesium sulphate, kaolin
4. Microorganisms: penicillin, streptomycin, griseofulvin.
5. Semisynthetic: Hydromorphine, hydrocodone
6. Synthetic: Most of the drugs used today are synthetic, e.g.
aspirin, paracetamol.
7. Genetic engineering: Human insulin, human growth hormone
etc.