Alcohol interaction of lormetazepam, mepindolol sulphate and diazepam measured by performance on the driving simulator.

Sixteen healthy volunteers of a mean age of means = 26.4 years took part in a driving simulator test in an eightfold crossover study under double-blind conditions. The additional influence of alcohol was tested acutely after a single administration of 2 mg lormetazepam, a new, highly effective derivative from the benzodiazepine class, 10 mg mepindolol sulphate, a new betablocker without sedating properties, and 10 mg diazepam. All drugs were compared with placebo and the test was performed 1, 2 and 3 hours after oral intake. The aim was to investigate particularly the risks relevant in road traffic caused by simultaneous intake of these substances with alcohol. For this purpose, besides the driving simulator, an accurate reaction test ( WDG ) and self-rating scales were used, the latter in order to assess subjective stress and anxiety levels. Lormetazepam, due to its strong sedating property, showed a reduction in driving performance and an increase in reaction time and pulse rate as compared with placebo, and these effects were highly potentiated by alcohol. Mepindolol sulphate expectedly reduced pulse rate when compared with placebo, otherwise there were no significant differences. Diazepam, when compared with placebo, like lormetazepam caused a reduction in driving performance and reaction capacity and an increase in pulse rate, but intensity and duration of this effect were less than with lormetazepam and did not reach statistical significance. No significant potentiating effects were observed after the additional application of alcohol.