Alpidem, an imidazo-
pyridine compound, has been evaluated as an
anxiolytic in comparison with placebo and
lorazepam. In the first of our normal volunteer studies, we compared single doses of
alpidem, 25, 50 and 100 mg with
lorazepam 2 mg and placebo on a range of cognitive, psychomotor and EEG variables.
Lorazepam and the highest (100 mg) dose of
alpidem impaired performance on a range of psychomotor tasks, the effects of the
benzodiazepine being more severe and more prolonged. No impairment of performance was observed with the 25 and 50 mg doses. In the second study, the focus was on memory functions.
Lorazepam, 2 mg, caused
anterograde amnesia which was most apparent 1 h post-
drug but persisted until 4 h: sedation was marked. By contrast, single doses (25, 50 mg) of
alpidem had little effect on either memory or alertness. The third study compared the effects of
alpidem (25, 50 mg) and
lorazepam (1 mg) with placebo, each given twice-daily for 8 days to normal volunteers. On the final day, a test dose of
ethanol was given.
Lorazepam impaired many tests of cognitive and psychomotor function, and this impairment was enhanced by
ethanol. By contrast,
alpidem produced less impairment with less interaction with alcohol. In a fourth, clinical, study, 24 patients with a DSM III primary diagnosis of generalised
anxiety disorder were treated, under double blind conditions, with doses adjusted according to clinical need of either
alpidem 25-150 mg daily or
lorazepam 1-6 mg daily.(ABSTRACT TRUNCATED AT 250 WORDS)