Drugs are classified in different ways as different modes of classification are useful to different categories of persons dealing with drugs. For example, classification of drugs on the basis of pharmacological effect is most useful for doctors because it provides them the whole range of drugs available for the treatment of a particular type of disease. On the other hand, classification of drugs on the basis of chemical structure or on the basis of molecular targets is useful for medicinal chemists, who are involved in designing and synthesis of drugs.
