The `hangover' effects of various hypnotic drugs were assessed in three successive experiments, all following the same design and protocol and using the same standardised driving test. Two doses of each of flurazepam (15 and 30 mg) and loprazolom (1 and 2 mg) and one dose of flunitrazepam (2 mg), nitrazepam (5 mg), secobarbital (200 mg) and zopiclone (7,5 mg) were separately administered to female volunteers who in the recent past had use prescribed hypnotic drugs for treatment of insomnia. After two successive nights of treatment, the subjects undertook two identical driving tests (morning and afternoon) in normal traffic on a primary highway. The test consisted of operating an instrumented vehicle over a distance of 100 km while attempting to hold its lateral position steady within the right (slower) traffic lane, and its speed, constant at 90 km/h. All hypnotics, except nitrazepam 5 mg, had, depending upon dose and time after ingestion, a negative effect on driving performance. In two other experiments the hangover effects of flurazepam 30 mg, nitrazepam 10 mg and temazepam 20 mg on driving performance were studied during a period of nocturnal medication lasting 7 successive days. Tests were administered, morning and afternoon, after the 2nd, 4th and 7th dose. The results were as follows: for flurazepam, a maximal deleterious effect after the 4th dose, less but still present after the 7th; for nitrazepam a similar though smaller effect over days, greater in the afternoon; and for temazepam, no significant effect. (A)
Abstract