Effects of repeated dose nitrazepam and lormetazepam on psychomotor performance in the elderly.

The daytime psychomotor performance of 12 healthy subjects of mean age 81.4 years was examined in a double-blind crossover study following single and repeated nightly doses of nitrazepam 5 mg, lormetazepam 1 mg, and placebo. Accuracy of performance on the Gibson spiral maze was unaffected by both drugs. On a reciprocal tapping task, speed was similarly unaffected. However, while neither drug significantly impaired accuracy on reciprocal tapping after the first dose, nitrazepam, but not lormetazepam, significantly reduced overall accuracy after seven consecutive doses, an effect consistent with drug accumulation.