Temazepam (brand names Restoril and Normison, among others) is an intermediate-acting 3-hydroxy hypnotic of the benzodiazepine class of psychoactive drugs. It is the 3-hydroxyanalogue of diazepam, and one of the diazepam’s primary active metabolites. In the US, temazepam is approved for the short-term treatment of insomnia. In addition, temazepam has anxiolytic (antianxiety), anticonvulsant, and skeletal muscle relaxant properties.
Temazepam is a white, crystalline substance, very slightly soluble in water, and sparingly soluble in alcohol. Its main pharmacological action is to increase the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABAA receptor. This causes sedation, motor impairment, ataxia, anxiolysis, an anticonvulsant effect, muscle relaxation, and a reinforcing effect. As a medication before surgery, temazepam decreased cortisol in elderly patients. In rats, it triggered the release of vasopressin into paraventricular nucleus of the hypothalamus and decreased the release of ACTH under stress