Dose response curve for the phase-shifting effect of triazolam on the mammalian circadian clock.

A dose response curve for the phase shifting effect of triazolam, a short-acting benzodiazepine commonly prescribed for the treatment of insomnia, on the circadian rhythm of locomotor activity was measured for the golden hamster. A single intraperitoneal injection of triazolam six hours before the onset of wheel-running activity induced a dose-dependent phase advance in the rhythm. A maximum phase advance, which averaged about 100 minutes, was observed in animals injected with 0.5 to 5.0 mg of triazolam. The use of drugs which promote sleep, and induce phase shifts in a central circadian clock, could be important in the treatment of sleep disorders associated with disrupted schedules and of mental and physical disorders associated with abnormal circadian rhythmicity.