The acute effect of quazepam on the sleep of chronic insomniacs. A dose-response study.

The present study investigated the effects of the benzodiazepine, 7-chloro-5-(2-fluorophenyl)-1,3-dihydro-1-(2,2,2-trifluoroethyl)-2H-1,4-benzodiazeepine-2-thione (quazepam), on hypnotic efficacy and sleep staging in chronic insomniacs. We evaluated the acute withdrawal effects of several doses (0, 7.5, 30 and 45 mg) of quazepam. The effects of the different doses were assessed using both objective (polysomnographic) and subjective sleep parameters in a double blind repeated measures design (n = 15). The results indicated that daily administration of quazepam over three nights produced increased effects on sleep which suggested drug accumulation. Lower doses (7.5 and 15 mg) only had significant effects on sleep (sleep induction and maintenance and sleep architecture) with three days of administration, while 45 mg of quazepam produced significant effects on the first night of drug administration. Contrary to previous research investigating longer periods of administration, acute administration of low doses of quazepam did not produce carryover effects on withdrawal, while higher doses did. The accumulation of the parent compound or its active metabolites thus seemed to mediate these effects on sleep in a dose related fashion.

RCT Entities:   Population Interventions Outcomes