Fosinopril and Spironolactone interaction

Fosinopril and Spironolactone: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Fosinopril (Fosinopril Sodium) label · effective 2024-05-16

Moderate

Symptomatic hypotension is most likely to occur in patients who have been volume- and/or salt-depleted as a result of prolonged diuretic therapy, dietary salt restriction, dialysis, diarrhea, or vomiting.

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Moderate

In such patients, fosinopril sodium therapy should be started under close medical supervision; they should be followed closely for the first 2 weeks of treatment and whenever the dose of fosinopril or diuretic is increased.

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Moderate

Consideration should be given to reducing the diuretic dose in patients with normal or low blood pressure who have been treated vigorously with diuretics or who are hyponatremic.

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Moderate

Drug Interactions Diuretics Patients on diuretics, especially those with intravascular volume depletion, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with fosinopril sodium tablets.

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Moderate

Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) or potassium supplements can increase the risk of hyperkalemia.

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From the Spironolactone label · effective 2026-08-26

Moderate

This risk is increased by impaired renal function or concomitant potassium supplementation, potassium-containing salt substitutes or drugs that increase potassium, such as angiotensin converting enzyme inhibitors and angiotensin receptor blockers [see Drug Interactions ( 7.1 )] .

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Moderate

Hypotension and Worsening Renal Function Excessive diuresis may cause symptomatic dehydration, hypotension and worsening renal function, particularly in salt-depleted patients or those taking angiotensin converting enzyme inhibitors and angiotensin II receptor blockers.

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Moderate

Examples of drugs that can increase potassium include: ACE inhibitors angiotensin receptor blockers aldosterone blockers non-steroidal anti-inflammatory drugs (NSAIDs) heparin and low molecular weight heparin trimethoprim 7.2 Lithium Like other diuretics, spironolactone oral suspension reduces the renal clearance of lithium, thus increasing the risk of lithium…

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Minor

Check serum potassium levels when ACE inhibitor or ARB therapy is altered in patients receiving spironolactone oral suspension.

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Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

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Not 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.