The classification of drugs and the reasons for classification are as follows: (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. Hence, it is the most useful to medicinal chemists.
