Effect of the selective MAO-A inhibitors brofaromine, clorgyline and moclobemide on human platelet MAO-B activity.

MAO-B activity was compared in healthy volunteers following oral treatment with clinically effective doses of the selective MAO-A inhibitors brofaromine (100 mg q.d. for 14 days), moclobemide (150 mg t.i.d. for 14 days) and clorgyline (5 mg t.i.d. for 10 days). Brofaromine and clorgyline did not alter platelet MAO activity. Following moclobemide treatment, MAO-B activity was reduced by 32% (p less than 0.05). It recovered during the 5 subsequent days after discontinuation of treatment. These results confirm earlier findings. The explanation for this finding may be that metabolites of moclobemide are active inhibitors of MAO-B.