(i) Antipyretics: They are the compounds which are used to bring down body temperature in high fever. Examples: aspirin, antipyrine, phenacetin, and paracetamol.


(ii) Antiseptics: They are the chemicals which kill or prevent the growth of micro-organisms. Antiseptics are applied to living tissues. They can be applied to wounds, cuts, ulcers diseased skin surface. Example: 0.2% solution of phenol.


(iii) Tranquilizers: Tranquilizers and analgesics are neurologically activer drugs. These affect the message transfer mechanism from nerve to receptor. Tranquilizers reduce anxiety and bring about calmness. These are used for making sleeping pills, Barbituric acid, lyminal, Seconal are commonly used as tranquilizers. They are habit forming and frequent and indiscriminate use leads to addiction.


(iv) Wide spectrum antibiotics : Broad-spectrum antibiotics are those which attack a wide range of micro organism. Such antibiotics are medicines effective against various harmful microorganism. For example, tetracycline, chloramphenicol and a mixture of potent antibiotics.