Lithium. Other kaliuretic diuretics, laxatives, corticosteroids, ACTH, amphotericin, carbenoxolone, penicillin G Na, salicylic acid derivatives. May increase K levels or induce hyperkalemia w/ ACE inhibitors, K-sparing diuretics, K supplements, salt substitutes containing K, cyclosporin, heparin Na. Serum K disturbances w/ class Ia antiarrhythmics, class III antiarrhythmics, antipsychotics (eg, thioridazine, chlorpromazine, levomepromazine, trifluoperazine, cyamemazine, sulpiride, sultopride, amisulpride, tiapride, pimozide, haloperidol, droperidol); others (eg, bepridil, cisapride, diphemanil, erythromycin IV, halofantrine, pentamidine, sparfloxacin, terfenadine, vincamine IV). Thiazide-induced hypokalemia w/ digitalis glycosides. Increase in digoxin peak plasma conc. May increase hypotensive effect or other antihypertensive agents. Oral antidiabetics & insulin. Risk of lactic acidosis w/ metformin. Cholestyramine & colestipol resins. NSAIDs (ie, ASA, COX-2 inhibitors & non-selective NSAIDs). Decrease noradrenaline effects. Tubocurarine. May raise level of serum uric acid of probenecid, sulfinpyrazone & allopurinol. May increase Ca level of Ca salts. May enhanced hyperglycemic effect of β-blocker & diazoxide. Atropine, biperiden. Amantadine. May reduce renal excretion & potentiation of myelosuppressive effects of cyclophosphamide, MTX; baclofen, amifostine; may aggravate orthostatic hypotension w/ alcohol, barbiturates, narcotics or antidepressants.