Development of serotonin syndrome w/ non-selective, irreversible MAOIs; reversible, selective MAO A inhibitor (moclobemide); selegiline (irreversible MAO B inhibitor); serotonergic medicinal products (eg, tramadol, sumatriptan & other triptans). Mean increase in QTc interval w/ pimozide. Capable of lowering seizure threshold w/ antidepressants (tricyclics, SSRIs), neuroleptics (phenothiazines, thioxanthenes, butyrophenones), mefloquine, bupropion & tramadol. Enhanced effects w/ lithium or tryptophan. Increased incidence of adverse reactions w/ St. John's wort. Altered anti-coagulant effects w/ oral anticoagulants. May increase bleeding tendency w/ NSAIDs. Not advisable w/ alcohol. Moderate increase in plasma conc w/ CYP2C19 inhibitors (eg, omeprazole, fluoxetine, fluvoxamine, lansoprazole, ticlopidine) & w/ cimetidine. Increase in plasma levels of medicinal products that are mainly metabolised by enzyme CYP2D6, & that have narrow therapeutic index eg, flecainide, propafenone & metoprolol; or some CNS acting medicinal products eg, desipramine, clomipramine & nortriptyline; or antipsychotics like risperidone, thioridazine & haloperidol. Concomitant use w/ medicinal products that are metabolised by CY2C19.