Psychomotor and memory effects of two adinazolam formulations assessed by a computerized neuropsychological test...

The memory effects of adinazolam were assessed using the computerized neuropsychological test battery (CNTB). In a single-blind crossover study, 12 volunteers received 2 x 20 mg adinazolam mesylate immediate-release (CT) tablets, 2 x 30 mg sustained-release (SR) tablets, and placebo. Plasma adinazolam and N-desmethyladinozolam (NDMAD) were determined by high-pressure liquid chromatography. Choice reaction time and word-list-learning/delayed-recall CNTB modules were administered at 0, 1, 3 and 6 hours after dosing. Adinazolam and NDMAD maximum peak plasma concentration were lower after SR tablets. Immediate-release tablets significantly prolonged reaction time compared with placebo and SR tablets; reaction time after SR tablets did not differ from placebo. Differences between SR and CT tablets in memory were significant only at 1 hour, but memory scores tended to be higher after SR tablet administration than after the CT tablet. At all times, memory scores were significantly lower than placebo for active treatments. Results suggest that memory is more impaired at lower NDMAD concentrations than is psychomotor function.