• Chemistry plays a vital role in improving the quality of human life.
  • The materials like, soaps, household bleach, tooth pastes are all made up of chemical compounds.
  • We ourselves are beautiful chemical creations and all our activities are controlled by chemicals


Chemical substances of natural or synthetic origin which are used for curing diseases and reducing suffering from pain are called medicines.

Antibiotics, antioxidants etc.

The branch of chemistry which deals with the treatment of diseases using suitable chemicals is known as chemotherapy.

A medicine is a substance which cares the disease, is safe to use, has negligible toxicity and does not causes the addiction.

Example:- Priceline

A chemical substance which also cures the disease but is habit forming, causes addition and serious side effects. Histamine, Ranitidine.


1. On the basis of Pharmacological Effect:-
On the basis of pharmacological effects it becomes useful for doctors because it provides then the whole range of drug available for treatment of particular dieses.
Examples:- Antiseptics, Antacids.

2. On the basis of Drug action:-
This classification of a drug is based upon biochemical process.
All antihistamines inhibit the action of histamine which causes inflammation in the body.

3. On the basis of Chemical Structure:-
Drugs have also been classified on basis of their chemical structure drugs having common structural features have similar pharmalogical activity.

Structure feature of sulphonamide

4. On the basis of molecular targets:-

The macromolecules such as carbohydrates, nucleic acids, lipids are attacked by drugs and are called drug targets. Drug possessing, some common structural feature may have the same mechanism of action on a target molecule.

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