Why do we need to classify drugs in different ways ?

Hello Jayant
There are a vast no. of drugs and we cant keep them in a single category since they are different in structure and they show different action. even when they enter the body the affect on different target. There fore there is a need to categorise these drugs on various basis as--
(i) On the basis of pharmacological effect:
This classification provides doctors the whole range of drugs available for the treatment of a particular type of problem. Hence, such a classification is very useful to doctors.

(ii) On the basis of drug action:
This classification is based on the action of a drug on a particular biochemical process. Thus, this classification is important.

(iii) On the basis of chemical structure:
This classification provides the range of drugs sharing common structural features and often having similar pharmacological activity.

(iv) On the basis of molecular targets:
This classification provides medicinal chemists the drugs having the same mechanism of action on targets.