The differential effects of short- and long-acting benzodiazepines upon nocturnal sleep and daytime performance.

Hypnotic drugs are the most frequent medical intervention for providing symptomatic relief of insomnia. Both effective amelioration of the insomnia complaint and the minimization of residual effects upon daytime performance must be considered in the selection of these medications. Data are presented here which compare the effects of short- and long-acting benzodiazepines upon sleep and upon waking performance. Unlike short-acting hypnotics with half-lives of up to 10 h (lorazepam, triazolam and temazepam), long-acting hypnotics with half-lives of up to 100 h (flurazepam, ketazolam) produce suppression of both REM and Stage 3--4 sleep which persists during the drug withdrawal (recovery) period. The half-life of hypnotics is also directly related to the duration of residual effects upon daytime performance. Hypnotics with long half-lives (flurazepam) produce more prolonged performance decrements than hypnotics with short half-lives (temazepam). In insomniacs, both effects upon sleep and upon walking performance must be considered in the selection of a hypnotic.