Serious reactions w/ MAOIs ie, moclobemide, linezolid, selegiline. Increased conc w/ CYP2C19 & cimetidine. Concomitant w/ tramadol, sumatriptan & other triptans may lead to serotonin syndrome. Decreased seizure threshold w/ TCAs, SSRIs, neuroleptics, mefloquine, bupropion. Lithium, tryptophan. Altered anticoagulant effects. Flecainide, propafenone, metoprolol, desipramine, clomipramine, nortriptyline, risperidone, thioridazine, haloperidol, class IA & III antiarryhthmics, ziprasidone, methadone, moxifloxacin, diuretics, laxatives, enemas, amphotericin B, corticosteroids (high dose). Wait until 24 hr after the last dose of linezolid.