What is a Class of Drugs?

The Food and Drug Administration (FDA) categorizes drugs in many ways. A category may be based on the chemical ingredients, the method by which a drug is used (by mouth, by injection, applied to the skin), the organ in the body that is treated (stomach, head, eye), and so on. Any one of these categories is called a class, and any drug fitting the criteria belongs to that class of drugs.

Drug Classes Arranged by Condition
For consumers, the most useful method of classification is the condition that the drugs help to treat or prevent. In other words, what does the class of drugs do for you?

Condition	Class of Drug
Allergies	Antihistamines
Infections Common cold caused by bacteria Wound or cut to the skin Pneumonia Inner ear inflammation	Antibiotics
Depression	Anti-depressants
Diabetes	Insulin Oral anti-diabetic drugs
Pain	Analgesics
Arthritis	Non-Steroidal Anti-inflamic Drugs
Gastrointestinal Ulcers Reflux disease Excess acid	Histamine-2 Blockers Proton Pump Inhibitors
High Cholesterol	Lipid-lowering drugs

Many different drugs fall into the "antihistamines" class, for example, and more than one of them may be effective at treating your particular condition. This is why it is so important to understand the idea of drug class, in addition to generic equivalent.