Quinapril and Triamterene and hydrochlorothiazide interaction
Quinapril and Triamterene 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 Quinapril label · effective 2024-05-15
…sometimes associated with oliguria and/or progressive azotemia, and rarely with acute renal failure and/or death, include patients with the following conditions or characteristics: heart failure, hyponatremia, high dose diuretic therapy, recent intensive diuresis or increase in diuretic dose, renal dialysis, or severe volume and/or salt depletion of any etiology.
No pharmacokinetic interaction was observed when single doses of quinapril hydrochloride and hydrochlorothiazide were administered concomitantly.
It may be advisable to eliminate the diuretic (except in patients with heart failure), reduce the diuretic dose or cautiously increase salt intake (except in patients with heart failure) before initiating therapy with quinapril hydrochloride in patients at risk for excessive hypotension who are able to tolerate such adjustments.
Such patients should be followed closely for the first two weeks of treatment and whenever the dose of quinapril hydrochloride and/or diuretic is increased.
If symptomatic hypotension develops, a dose reduction or discontinuation of quinapril hydrochloride or concomitant diuretic may be necessary.
From the Triamterene and hydrochlorothiazide label · effective 2026-07-16
Drug Interactions Angiotensin-Converting Enzyme Inhibitors Potassium-sparing agents should be used with caution in conjunction with angiotensin-converting enzyme (ACE) inhibitors due to an increased risk of hyperkalemia.
Thiazides may add to or potentiate the action of other antihypertensive drugs.
See INDICATIONS AND USAGE for concomitant use with other antihypertensive drugs.
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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.