These are a widely used group of substances many people think too widely. They include tranquillizers and seadatives and vary from mildly anxiety reducing to quite potent hypnotics.

They are valuable preparations in combating anxiety and tension, and also relieve muscle spasm. The chloriazepoxide variety (trade name: Librium) is often of benefit in reducing aggression. Diazepam (trade name: Valium) is valuable as pre medication before dental treatment and some types are edcellen anticonvulsants.

Dependency is not uncommon and excessive dosage can cause unsteadiness and drowsiness. Even in high dosage they are relatively safe and are now largely prescribed instead of barbiturates.