Captopril and Spironolactone interaction
Captopril and Spironolactone: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Captopril label · effective 2026-09-14
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…
Hypotension–Patients on Diuretic Therapy Patients on diuretics and especially those in whom diuretic therapy was recently instituted, as well as those on severe dietary salt restriction or dialysis, may occasionally experience a precipitous reduction of blood pressure usually within the first hour after receiving the initial dose of captopril.
From the Spironolactone label · effective 2026-08-26
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 )] .
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.
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…
Check serum potassium levels when ACE inhibitor or ARB therapy is altered in patients receiving spironolactone oral suspension.
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.