Amiloride and Losartan and hydrochlorothiazide interaction
Amiloride and Losartan and hydrochlorothiazide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Amiloride (amiloride hydrochloride) label · effective 2023-05-05
Hyperkalemia occurs commonly (about 10%) when amiloride is used without a kaliuretic diuretic.
When amiloride HCl is used concomitantly with a thiazide diuretic in patients without these complications, the risk of hyperkalemia is reduced to about 1-2 percent.
It is thus essential to monitor serum potassium levels carefully in any patient receiving amiloride, particularly when it is first introduced, at the time of diuretic dosage adjustments, and during any illness that could affect renal function.
The risk of hyperkalemia may be increased when potassium-conserving agents, including amiloride HCl, are administered concomitantly with an angiotensin-converting enzyme inhibitor, an angiotensin II receptor antagonist, cyclosporine or tacrolimus.
Diabetes Mellitus In diabetic patients, hyperkalemia has been reported with the use of all potassium-conserving diuretics, including amiloride HCl, even in patients without evidence of diabetic nephropathy.
From the Losartan and hydrochlorothiazide (HYZAAR) label · effective 2025-11-26
Hypotension in Volume- or Salt-Depleted Patients In patients with an activated renin-angiotensin system, such as volume- or salt-depleted patients (e.g., those being treated with high doses of diuretics), symptomatic hypotension may occur after initiation of treatment with HYZAAR.
Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): increased risk of renal impairment and reduced diuretic, natriuretic, and antihypertensive effects.
Lithium Increases in serum lithium concentrations and lithium toxicity have been reported with concomitant use of angiotensin II receptor antagonists or thiazide diuretics.
Non-Steroidal Anti-Inflammatory Agents Including Selective Cyclooxygenase-2 Inhibitors Losartan Potassium In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result…
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.