Concomitant use w/ irreversible non-selective MAOIs & reversible, selective MAO-A inhibitor eg, moclobemide are contraindicated; reversible, non-selective MAOI eg, linezolid; irreversible, selective MAO-B inhibitor eg, selegiline; drugs that prolong QT interval eg, Class IA & III antiarrhythmics, antipsychotics (eg, phenothiazines, pimozide, haloperidol), TCAs, certain antimicrobials (eg, sparfloxacin, moxifloxacin, erythromycin IV, pentamidine, anti-malarians), certain antihistamines (eg, astemizole, mizolastine). Serotonin syndrome w/ serotonergic drugs eg, tramadol, sumatriptan & other triptans. Seizure threshold may be lowered w/ antidepressants, neuroleptics, mefloquine, bupropion & tramadol. May have enhanced effects w/ lithium & tryptophan. Increased adverse reactions w/ herbal remedies containing St. John's wort (Hypericum perforatum
). May alter anti-coagulant effects of oral anticoagulants. Alcohol. Increased risk of malignant arrhythmias w/ hypokalaemia/hypomagnesaemia-inducing drugs. Moderate increased plasma conc w/ omeprazole & cimetidine. Drugs w/ narrow therapeutic index eg, flecainide, propafenone & metoprolol (when used in cardiac failure); antidepressants eg, desipramine, clomipramine or nortriptylline, antipsychotics eg, risperidone, thioridazine & haloperidol. May cause weak inhibition of drugs metabolised by CYP2C19.