Benazepril and Quinapril and hydrochlorothiazide interaction
Benazepril 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 Benazepril (Lotensin) label · effective 2025-09-30
CONTRAINDICATIONS Lotensin is contraindicated in patients: who are hypersensitive to benazepril or to any other ACE inhibitor with a history of angioedema with or without previous ACE inhibitor treatment Lotensin is contraindicated in combination with a neprilysin inhibitor (e.g., sacubitril).
Patients at risk of excessive hypotension include those with the following conditions or characteristics: heart failure with systolic blood pressure below 100 mm Hg, ischemic heart disease, cerebrovascular disease, hyponatremia, high dose diuretic therapy, renal dialysis, or severe volume and/or salt depletion of any etiology.
In such patients, follow closely for the first 2 weeks of treatment and whenever the dose of benazepril or diuretic is increased.
Risk factors for the development of hyperkalemia include renal insufficiency, diabetes mellitus, and the concomitant use of potassium-sparing diuretics, potassium supplements and/or potassium-containing salt substitutes [see Drug Interactions (7.1) ] .
Diuretics Hypotension Patients on diuretics, especially those in whom diuretic therapy was recently instituted, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with Lotensin.
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.
Quinapril and hydrochlorothiazide tablets should be used cautiously in patients receiving concomitant therapy with other antihypertensives.
Neutropenia/Agranulocytosis: Another ACE inhibitor, captopril, has been shown to cause agranulocytosis and bone marrow depression rarely in patients with uncomplicated hypertension, but more frequently in patients with renal impairment, especially if they also have a collagen vascular disease, such as systemic lupus erythematosus or scleroderma.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.