Drug

Drug, substance affecting the body and that may be used to treat illness or alleviate symptoms. Antibiotics, antitoxins, sulfa drugs, insulin, narcotics, contraceptives, stimulants, depressants, the special drugs used in chemotherapy to treat cancers are just a few of the many drugs that have transformed medical practice.

Drugs may be derived from organic substances, they may be manufactured through chemical modifications of natural products, or they may be synthetic. Some can be purchased over the counter, while others require a doctor's prescription. Drug research and the manufacture of new drugs has become a highly complex, technologically sophisticated, and highly capitalized industry. In the U.S. newly developed drugs are closely monitored by the Food and Drug Administration, which has authority over their testing and marketing. The modern pharmacopeia is so large that specialists must keep abreast of new developments through constantly revised standard references like the United States Pharmacopeia—National Formulary and the Physician's Desk Reference.

Side by side with scientific progress in the development of new drugs and their applications to medicine, there has been an increase in the manufacture, trade, and use of various narcotics. As a result, social, political, and religious institutions have tried to formulate responses to substances that, in one form or another, raise far-reaching ethical, moral, and legal questions.