Blood plasma
Serotonin syndrome has been reported when moclobemide has been taken in combination with other serotonin enhancing drugs; however, due to moclobemide's reversible MAO inhibition, serotonin syndrome is significantly less likely to occur with moclobemide than with older irreversible MAOIs. Serotonin syndrome has been reported when trazodone was abruptly replaced with moclobemide. Taking at the same time or starting moclobemide too soon after discontinuing clomipramine, or other serotonin reuptake inhibitors, such as SSRIs may result in the development of a serotonin syndrome. SNRIs, such as venlafaxine in combination with moclobemide have also been associated with serotonin syndrome. Cimetidine, causes a doubling of the blood plasma levels of moclobemide. Blood plasma levels of trimipramine and maprotiline and possibly other tricyclic antidepressants increase when used in combination with moclobemide and may require dosage adjustments if the combination is used for treatment resistant depression. The elimination of zolmitriptan is reduced by moclobemide and if the combination is used, a dosage reduction of zolmitriptan is recommended. Moclobemide reduces the metabolism of dextromethorphan. Moclobemide may decrease metabolism of diazepam, omeprazole, proguanil, propranolol, and others due to inhibition of CYP2C19.