The effects of moclobemide on autonomic and cognitive functions in healthy volunteers.

BACKGROUND

Moclobemide, a reversible and selective inhibitor of the MAO-A isoenzyme, is marketed as an antidepressant that lacks autonomic and cognitive side effects. However, only few and inconclusive quantitative data on the effects of moclobemide on autonomic and cognitive functions have been reported in the literature. Therefore, a double-blind, randomized, placebo-controlled crossover trial was performed.

METHODS

Twelve healthy male volunteers (age 22-29 years) received orally 150 mg moclobemide b.i.d. and placebo for 14 days each. Heart rate variability (HRV) and skin conductance response (SCR) following sudden deep breath were employed as parameters for autonomic function. Quantitative EEG (qEEG) and psychometric tests served as parameters for cognitive function. Measurements were performed before the start of drug administration and repeatedly on the last treatment day.

RESULTS

Parameters of HRV and SCR were not changed by multiple dosing with moclobemide (P > 0.05). Neither cognitive functions such as flicker fusion frequency, memory, choice reaction time, and psychomotor performance nor qEEG was significantly influenced, but subjective tiredness was decreased at all time points of measurement after multiple dosing with moclobemide (P < 0.05).

CONCLUSIONS

In conclusion, moclobemide does not appear to influence autonomic functions or cognitive functions when given subchronically to healthy humans. In contrast, changes in subjective mood hint at a subtle activating effect.