Captopril and Quinapril and hydrochlorothiazide interaction
Captopril and Quinapril 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 Captopril label · effective 2026-09-14
CONTRAINDICATIONS Captopril tablets are contraindicated in patients who are hypersensitive to this product or any other angiotensin- converting enzyme inhibitor (e.g., a patient who has experienced angioedema during therapy with any other ACE inhibitor).
Hypotension Excessive hypotension was rarely seen in hypertensive patients but is a possible consequence of captopril use in salt/volume depleted persons (such as those treated vigorously with diuretics), patients with heart failure or those patients undergoing renal dialysis (see PRECAUTIONS : Drug Interactions ).
Patients should be followed closely for the first two weeks of treatment and whenever the dose of captopril and/or diuretic is increased.
In patients with heart failure, reducing the dose of diuretic, if feasible, may minimize the fall in blood pressure.
Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) 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 ACE inhibitors, including captopril, may result in deterioration…
From the Quinapril and hydrochlorothiazide label · effective 2023-12-11
Like other ACE inhibitors, quinapril has been only rarely associated with hypotension in uncomplicated hypertensive patients.
The thiazide component of quinapril and hydrochlorothiazide tablets may potentiate the action of other antihypertensive drugs, especially ganglionic or peripheral adrenergic- blocking drugs.
As with other ACE inhibitors, periodic monitoring of white blood cell counts in patients with collagen vascular disease and/or renal disease should be considered.
Agranulocytosis did occur during quinapril treatment in one patient with a history of neutropenia during previous captopril therapy.
Quinapril and hydrochlorothiazide tablets should be used cautiously in patients receiving concomitant therapy with other antihypertensives.
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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.