COMPARATIVE AMNESIC AND SEDATIVE EFFECTS OF LORAZEPAM AND OXAZEPAM INHEALTHY-VOLUNTEERS

Oxazepam and its chlorinated derivative, lorazepam, have similar half- lives but differing potencies. This study compared the effects of thes e two benzodiazepines with a placebo on memory, mood and psychomotor f unction. Thirty six volunteers took part in a double-blind, independen t groups design. Subjects completed a battery of tests before and 2.5 h after drug administration. Lorazepam 2 mg produced more profound sub jective and motor sedation than oxazepam 30 mg, and this in turn produ ced a similar, global pattern of impairments across a wide range of ta sks. However, lorazepam produced greater decrements than oxazepam on a task involving episodic memory even when sedative effects were partia lled out. We suggest that this finding may reflect either differential task sensitivities or a contribution of priming to performance on the explicit memory task.