A large family of drugs used as HYPNOTICS, ANXIOLYTICS, TRANQUILLISERS, ANTICONVULSANTS, premedicants, and for intravenous sedation. Short-acting varieties are used as hypnotics; longer-acting ones as hypnotics and tranquillisers. Those with high lipid solubility act rapidly if given intravenously.
Benzodiazepines act at a speciﬁc centralnervous-system receptor or by potentiating the action of inhibitory neuro-transmitters. They have advantages over other sedatives by having some selectivity for anxiety rather than general sedation. They are safer in overdose. Unfortunately they may cause aggression, amnesia, excessive sedation, or confusion in the elderly. Those with long half-lives or with metabolites having long half-lives may produce a hangover eﬀect, and DEPENDENCE on these is now well recognised, so they should not be prescribed for more than a few weeks. Commonly used benzodiazepines include nitrazepam, ﬂunitrazepam (a controlled drug), loprazolam, temazepam (a controlled drug) and chlormethiazole, normally conﬁned to the elderly. All benzodiazepines should be used sparingly because of the risk of dependence.