Drugs are classified on the basis of –

• Chemical structure

• Basis of drug action

• Basis of molecular targets

• Basis of pharmacological effect

Out of which classification on the basis of molecular targets is most useful for medicinal chemists.

This classification is based on the macromolecule the drugs interact with. The drug targets can be lipids, proteins, nucleic acids, carbohydrates or any other such biomolecule. The drugs with similar structures have similar reactions with such biomolecules.