Risk of serotonin syndrome w/ irreversible MAOI, reversible MAO-A inhibitor eg, moclobemide, selegiline & serotonergic medicinal products (eg, tramadol, sumatriptan & other triptans). Non-selective, irreversible MAOIs. Reversible non-selective MAOI eg, linezolid. Medicinal products that prolong QT interval eg, class IA & III antiarrhythmics, antipsychotics (eg, phenothiazine derivatives, pimozide, haloperidol), TCAs, certain antimicrobial agents (eg, sparfloxacin, moxifloxacin, erythromycin IV, pentamidine, anti-malarial treatment particularly halofantrine), certain anti-histamines (astemizole, mizolastine). Moderate increase in plasma conc w/ cimetidine. Medicinal products that lower seizure threshold (eg, antidepressants, neuroleptics eg, phenothiazines, thioxanthenes & butyrophenones, mefloquine, bupropion & tramadol). Enhanced effects w/ lithium, tryptophan. Increased incidence of adverse reactions w/ St. John's wort. Altered anti-coagulant effects w/ oral anti-coagulants. May increase bleeding tendency w/ NSAIDs. Moderate increase in plasma conc w/ omeprazole. CYP2C19 inhibitors. Flecainide, propafenone, & metoprolol, some CNS acting medicinal products, antidepressants eg, desipramine, clomipramine & nortriptyline or antipsychotics eg, risperidone, thioridazine & haloperidol. Increased plasma conc w/ desipramine or metoprolol.