Pharmacokinetics and metabolism of various benzodiazepines used as hypnotics.

1 In the management of insomnia with drugs, any action should be restricted to the duration of the night and residual effects should be absent during the day-time. The intermittent type of drug action desired is fundamentally different from drug treatment where a constant effect is sought. 2 Duration of drug action is dependent on the kinetics of distribution and elimination of the parent drug and its effective metabolites. In addition biopharmaceutical factors, such as those which promote a rapid rate of absorption, are important. 3 These considerations serve as a guide for a review of the kinetics and metabolism of various benzodiazepines.