PSYCHOMOTOR EFFECTS OF THE ANXIOLYTIC ABECARNIL - A COMPARISON WITH LORAZEPAM

Abecarnil is a metabolically stable beta-carboline that binds with hig h affinity and selectivity to central benzodiazepine receptors. The ef fects on cognitive and psychomotor skills of abecarnil (ZK 112-119), 2 .5 mg and 5.0 mg, were compared with lorazepam 2.0 mg and placebo. Twe nty-four healthy, young males participated in a double-blind, four-way Latin square design and performed batteries of behavioral tests at pr edrug and at 20, 40, 60, 80, 100, 120, 180, 240, 360 and 480 min after drug administration. Abecarnil 5.0 mg and lorazepam 2.0 mg displayed similar impairment profiles in tests of cognitive functions including memory encoding. Abecarnil 2.5 mg was substantially less impairing tha n lorazepam. Impairment levels of the abecarnil and lorazepam treatmen ts peaked at 2-3 h after oral administration. The two abecarnil doses showed dose-dependent effects on the cognitive and psychomotor tasks. All three drug treatments were well tolerated by the subjects, with no one terminating early due to adverse events. The incidence of reporte d adverse events for abecarnil was dose-dependent. The most frequent, statistically significant adverse effects were drowsiness, lack of con centration and visual disturbance for abecarnil 5.0 mg; and lack of co ncentration and dizziness for lorazepam 2.0 mg. There were no signific ant differences in adverse incidence rates between abecarnil 2.5 mg an d placebo.