Risk of increased plasma lithium. Increased risk of ventricular arrhythmias w/ class Ia antiarrhythmics (quinidine, hydroquinidine, disopyramide); class III antiarrhythmics (amiodarone, sotalol, dofetilide, ibutilide);
some antipsychotics eg, phenothiazines (chlorpromazine, cyamemazine, levomepromazine, thioridazine, trifluoperazine), benzamides (amisulpride, sulpiride, sultopride, tiapride); butyrophenones (droperidol, haloperidol); others eg, bepridil, cisapride, diphemanil, erythromycin IV, halofantrine, mizolastine, pentamidine, sparfloxacin, moxifloxacin, vincamine IV. Risk of acute renal failure w/ NSAIDs including COX-2 selective inhibitors. Risk of sudden hypotension &/or acute renal failure w/ ACE inhibitors. Additive hypokalemic affect w/ amphotericin B (IV), gluco- & mineralocorticoids, tetracosactide, stimulant laxatives. Increased antihypertensive effect w/ baclofen. Digitalis prep. May increase hypersensitivity reactions to allopurinol. K-sparing diuretics (amiloride, spironolactone, triamterene). Metformin induced lactic acidosis. Increased risk w/ iodinated contrast media. Antihypertensive effect & increased risk of orthostatic hypotension w/ imipramine-like antidepressants, neuroleptics. Risk of hypercalcemia w/ Ca salts. Risk of increased plasma creatinine w/ ciclosporin, tacrolimus. Decreased antihypertesive effect w/ corticosteroids, tetracosactide (systemic route).