Alpidem and lorazepam in the treatment of patients with anxiety disorders: comparison of physiological and psychological effects.

The physiologcal and psychological effects of the novel imidazo-pyridine alpidem were compared with those of the benzodiazepine lorazepam in the context of a clinical trial. Twenty-three psychiatric out-patients with generalised anxiety disorder received alpidem (mean dose 112.5 mg daily) or lorazepam (mean 3.5 mg daily) in doses adjusted to clinical need under double-blind conditions. A battery of tests was performed before and after four weeks treatment. Anxiety scores improved very significantly in both groups with no subjective sedation nor other particular side-effects noted in either group. However, lorazepam reduced the EEG averaged evoked response and produced significant impairment in the reaction time and memory tests whereas alpidem had no such effects. Alpidem therefore shows promise as an effective anxiolytic devoid of the adverse psychomotor and cognitive effects often associated with the benzodiazepines.