Objective and subjective assessment of hangover during subacute administration of temazepam and nitrazepam to healthy subjects.

Fourteen, healthy students volunteered for a double-blind, cross-over trial of temazepam 20 mg (soft gelatine capsule), nitrazepam 10 mg (uncoated tablet) and placebo in matched formulations, single doses of each being given for 10 nights with a three-week wash-out period between each treatment. Residual drug effects were measured objectively (psychomotor skills) and subjectively (visual analogue scales) in the morning and afternoon of Days 0 (before the first tablet), 1 and 10. The subjects also recorded various events during each treatment period. Serum benzodiazepine concentrations were bioassayed in blood samples taken after the last assessment. Both benzodiazepines shortened sleep latency during the first few nights, and nitrazepam prolonged the duration of sleep. The residual effect of drowsiness was noted during the nitrazepam period, whilst temazepam proved less sedating. The 'morning after' effect was a subjective observation and not an objective measurement. The learning effect interfered with the complex objective assessments, and simple measurement of exophoria with the Maddox wing test provided the clearest objective evidence of drug effects. On Day 10 residual concentrations of nitrazepam were detectable in the serum whereas the level of temazepam was found to be low or negligible. It is concluded, that temazepam 20 mg in a soft gelatine capsule is a suitable hypnotic for subjects whose daily work requires constant alertness.