Amiloride + Captopril-hydrochlorothiazide

MediHelp rates the interaction as major. Amiloride and Captopril-hydrochlorothiazide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Amiloride is a potassium-sparing diuretic and captopril reduces aldosterone, so together they can cause significant hyperkalemia, especially in renal impairment or diabetes. The hydrochlorothiazide component partly offsets potassium retention but does not remove the risk. Additive blood pressure lowering may also occur.

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum potassium and creatinine at baseline, within the first week or so, and periodically thereafter. Avoid potassium supplements and salt substitutes, and stop amiloride if hyperkalemia develops.

MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.