Increased antihypertensive effect w/ other antihypertensive agents. Hypotension, hyperkalaemia & decreased renal function w/ aliskiren-containing products or ACE inhibitors. Reversible increased serum conc & toxicity of lithium. Increased serum K levels w/ K-sparing diuretics, K supplements, K-containing salt substitutes, heparin Na. Attenuated antihypertensive effect w/ NSAIDs ie, selective COX-2 inhibitors, ASA >3 g daily & non-selective NSAIDs. Increased C
max & AUC of repaglinide. Medicinal products affected by serum K disturbances eg, digitalis glycosides, antiarrhythmics. Hydrochlorothiazide: Potentiated orthostatic hypotension w/ alcohol. Dose adjustment of antidiabetic medicinal products. Impaired absorption w/ colestyramine & colestipol resins. Increased electrolyte depletion eg, hypokalaemia w/ corticosteroids, ACTH. Thiazide-induced hypokalaemia or hypomagnaesemia w/ digitalis glycosides. Reduced diuretic, natriuretic & antihypertensive effects w/ NSAIDs. Decreased effect of pressor amines eg, noradrenaline. Potentiated effect of nondepolarizing skeletal muscle relaxants eg, tubocurarine. Raised uric acid levels w/ antigout medicinal products. Increased incidence of hypersensitivity reactions to allopurinol. Increased serum Ca levels w/ Ca salts. Risk of symptomatic hyponatraemia w/ carbamazepine. Enhanced hyperglycaemic effect of β-blockers, diazoxide. Increased bioavailability by anticholinergic agents eg, atropine, beperiden. Increased risk of adverse effects by amantadine. Reduced renal excretion & potentiated myelosuppressive effects of cytotoxic medicinal products eg, cyclophosphamide, MTX.