Lisinopril and Furosemide: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Furosemide
Lisinopril
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Furosemide (Lasix) is a water pill that helps your body get rid of extra fluid, and lisinopril is a blood pressure medicine. Both lower your blood pressure, so taking them together can push it down too far. When you first start, you might feel dizzy, lightheaded, or faint, especially standing up. In some people this combo can also strain the kidneys.
The good news is that this pairing is used all the time on purpose, and your care team knows how to handle it. They may check your blood pressure and run blood tests on your kidneys, and adjust your doses to fit you. Keep taking both as prescribed, stay hydrated, and let your doctor know if you feel very dizzy.
Effect: Additive antihypertensive activity increases the risk of symptomatic hypotension and acute deterioration in renal function (including renal failure), particularly with volume depletion. This is a pharmacodynamic interaction; neither agent is a CYP prodrug relevant here.
- Mechanism: Furosemide-induced volume/sodium depletion plus lisinopril-mediated reduction in efferent arteriolar tone can lower glomerular filtration; paradoxically ACE inhibition may blunt diuretic natriuresis causing fluid retention.
- Onset: Unspecified; hypotension often seen early (first-dose).
- Evidence: Theoretical / severity rated major.
- Management: Monitor BP, serum creatinine, eGFR, and electrolytes; individualize dosing. Interrupt or reduce furosemide and/or the ACE inhibitor if needed. Consider starting low and correcting volume depletion first.
What happens
An increased risk of severe hypotension and deterioration in renal function, including renal failure
Interaction Deep Dive
Taking furosemide together with angiotensin converting enzyme (ACE) inhibitors can result in profound hypotension and worsening renal function, up to and including renal failure. Watch for shifts in blood pressure and renal function, and if necessary pause or lower the dose of both furosemide and the ACE inhibitor23. While this pairing would be expected to boost natriuresis, ACE inhibitors can paradoxically diminish glomerular filtration as well as the diuretic and natriuretic effects of diuretics, which may cause edema and fluid retention68.
Why it happens (mechanism)
Potentiated antihypertensive effects
How to manage this interaction
This combination is prescribed together often and can be managed well by your care team.
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may check your blood pressure and run blood tests for your kidneys and electrolytes, especially when starting or changing doses.
- The dose of either medicine may need to be adjusted and individualized by your care team, and one may be temporarily interrupted or reduced if needed.
- Rise slowly from sitting or lying down, and stay reasonably hydrated.
Tell your prescriber or pharmacist if you feel very dizzy, faint, weak, or notice much less urination or new swelling.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
4 reports — tap to read
a) One study found that captopril did not change the renal excretion or diuretic action of furosemide in hypertensive patients 4. Nevertheless, more recent findings show that standard doses of captopril reduce the natriuretic and diuretic effects of furosemide in patients with mild to moderate congestive heart failure. While on furosemide, sodium excretion rose by 623%; this fell to 242% when captopril was added 5. Several authors have described weight gain, sodium retention, and peripheral edema in patients receiving diuretic therapy after ACE inhibitors were started 678.
b) In a single-dose study, oral benazepril (10 mg) and oral furosemide (40 mg) were given both alone and together to 12 healthy volunteers. No significant effects on the pharmacokinetics of benazepril were observed. Urinary excretion of total furosemide fell by 10% to 20% during combined administration. When each drug was given alone as a single dose, blood pressure and pulse were not significantly affected. However, the combination produced a decrease in erect blood pressure and an increase in pulse rate. The greatest effects were seen four hours after administration (122 to 104 mm Hg and 87 to 107 beats per minute, respectively). Most subjects taking the combination experienced dizziness, which occurred together with reductions in blood pressure 9.
c) Combined captopril and furosemide therapy has been reported to enhance the hypotensive effects of captopril. In one patient with high plasma renin activity who was given 50 mg captopril and intravenous furosemide, blood pressure fell sharply from 290/150 mm Hg to 135/60 mm Hg within 10 minutes 10.
d) Severe postural hypotension has been reported when ACE inhibitors are combined with loop diuretic therapy. First dose hypotension is frequently seen in patients who have sodium depletion or hypovolemia resulting from diuretics or sodium restriction. This hypotensive response is generally transient 111219.
Common questions
Can I take Lisinopril and Furosemide together?
Taking furosemide and lisinopril together can lower blood pressure a lot and stress the kidneys, especially at first, so let your care team monitor you and adjust doses. Keep taking both as prescribed and report dizziness, fainting, or reduced urination. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lisinopril and Furosemide interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Lisinopril and Furosemide interaction managed?
This combination is prescribed together often and can be managed well by your care team. Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may check your blood pressure and run blood tests for your kidneys and electrolytes, especially when starting or changing doses. The dose of either medicine may need to be adjusted and individualized by your care tea… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Lisinopril or Furosemide need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (12)
- Vlasses PH, Ferguson RK, & Chatterjee K: Captopril: clinical pharmacology and benefit-to-risk ratio in hypertension and congestive heart failure. Pharmacotherapy 1982; 2:1-17. PubMed
- Product Information: FUROSCIX(R) subcutaneous injection, furosemide subcutaneous injection. scPharmaceuticals Inc (per FDA), Burlington, MA, 2025. DailyMed
- Product Information: LASIX® ONYU subcutaneous injection, furosemide subcutaneous injection. SQ Innovation, Inc (per manufacturer), Burlington, MA, 2025. DailyMed
- Fujimura A, Shimokawa Y, & Ebihara A: Influence of captopril on urinary excretion of furosemide in hypertensive subjects. J Clin Pharmacol 1990; 30:538-542. PubMed
- McLay JS, McMurray JJ, Bridges AB, et al: Acute effects of captopril on the renal actions of furosemide in patients with chronic heart failure. Am Heart J 1993; 126:879-886. PubMed
- Cleland JGF, Gillen G, & Dargie HJ: The effects of frusemide and angiotensin-converting enzyme inhibitors and their combination on cardiac and renal haemodynamics in heart failure. Eur Heart J 1988; 9:132-141. PubMed
- Odemuyiwa O, Gilmartin J, Kenny D, et al: Captopril and the diuretic requirements in moderate and severe chronic heart failure. Eur Heart J 1989; 10:586-590. PubMed
- Flapan AD, Davies E, Waugh C, et al: Acute administration of captopril lowers the natriuretic and diuretic response to a loop diuretic in patients with chronic cardiac failure. Eur Heart J 1991; 12:924-927. PubMed
- De Lepeleire I, Van Hecken A, Verbesselt R, et al: Interaction between furosemide and the converting enzyme inhibitor benazepril in healthy volunteers. Eur J Clin Pharmacol 1988; 34:465-468. PubMed
- Case DB, Atlas SA, Laragh JH, et al: Clinical experience with blockade of the renin-angiotensin-aldosterone system by an oral converting-enzyme inhibitor (SQ 14,255, captopril) in hypertensive patients. Prog Cardiovasc Dis 1978; 21:195-206.
- Clementy J, Schwebig A, Mazaud C, et al: Comparative study of the efficacy and tolerance of Capozide and Moduretic administered in a single daily dose for the treatment of chronic moderate arterial hypertension. Postgrad Med J 1986; 62(suppl 1):132.
- Gluck Z, Beretta-Piccoli C, & Reubi FC: Long-term effects of captopril on renal function in hypertensive patients. Eur J Clin Pharmacol 1984; 26:315-323. PubMed
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