Analgesics reduce pain without causing impairment of consciousness, mental confusion, incoordination or paralysis or some other disturbances of nervous system.
These are classified as follows:
i) Non-narcotic analgesis
ii)narcotic drugs

(ii) Antacids: They are the chemical substances which can reduce or neutralise the acidity. The function of the antacids is to neutralise the acidity and raise the pH level. They may also act as buffers i.e., they may now allow the pH level to fall when extra acids are released. The commonly used antacids contain magnesium salts (magnesium trisilicate) and aluminium salts (aluminium hydroxide and aluminium silicate).


(iii) Antifertility drugs: The anti-fertility drugs are mostly hormonal contraceptives. The mechanism of action of a combined oral pill is to prevent the release of the ovum from the ovary. This is achieved by blocking the pituitary secretion of gonadotropin hormone which is necessary for the ovulation to occur.
Progestogen-only preparations render the cervical mucus thick and scanty and thereby inhibit sperm pentetration. They also inhibit tubal motility and delay the transport which is necessary for the ovulation to occur.