Antipyretics are the substances which are used to reduce body temperature or to control fever.
The word antipyretic is derived from pyro which means fire (means hot), anti means against. Thus, antipyretic means it counteracts heat (high body temperature).
Aspirin, paracetamol and phenacetin are commonly used antipyretics. You can get them in the market with different trade names like crocin, anacin, disprin, etc.
Aspirin is the most popular antipyretic in use. It gets hydrolyzed in stomach and salicylic acid is released. Overdose and using it over a long time may cause side effects. It may cause bleeding in the stomach wall and even ulcers. Therefore, overdose and prolonged use should be avoided. However, calcium and sodium salts of aspirin are more soluble in water and are less harmful than aspirin.