The effects of 5 and 10 mg oral nitrazepam doses on manual skills, grip strength, and reaction time 8 hours after ingestion of the drugs were studied in 34 healthy female volunteers aged 19-22 years. 5 mg nitrazepam caused a slight but insignificant decrease in psychomotor skills. With 10 mg psychomotor skills were influenced significantly. Grip strength and reaction time were not influenced either by the 5 or 10 mg doses. The investigators corroborate the value of the established effects of nitrazepam as a hypnotic, but recommend that caution should be excercised in prescribing the drug as a hypnotic (especially in doses exceeding 5 mg) to work-aged subjects as there is a risk of significant effect on the psychomotor skills. Furthermore, the drug may cause fatigue.