Sildenafil and Furosemide Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Furosemide Injection
Sildenafil
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.
What happens
Increased risk of hearing loss
Interaction Deep Dive
In a case report, additive ototoxicity occurred in a patient treated with high-dose of furosemide, daily sildenafil (a CYP3A4 substrate) for pulmonary hypertension, and diltiazem (a CYP3A4 inhibitor). Caution is recommended when adding an ototoxic drug to sildenafil, especially with chronic use and in the presence of a concomitant CYP3A4 inhibitor. Consider monitoring for hearing loss1.
Why it happens (mechanism)
Additive otoxicity
Literature reports
1 report — tap to read
a) Acute profound bilateral hearing loss was reported in a 77-year-old man when sildenafil 20 mg orally 3 times daily was added for treatment of pulmonary hypertension to a 10-day regimen of 120 mg orally twice daily furosemide for right-sided heart failure. The patient also took daily diltiazem, a known CYP3A4 inhibitor that may have increased sildenafil drug levels. Baseline hearing deficits may have reduced the threshold for additional damage to occur. Hearing was improved after discontinuation of furosemide, and returned to normal following discontinuation of sildenafil. 1.
Common questions
Can I take Sildenafil and Furosemide Injection together?
Increased risk of hearing loss Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sildenafil and Furosemide Injection interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
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 Sildenafil or Furosemide Injection 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 anything you'd monitor while I'm on both?
References (1)
- Skeith L, Yamashita C, Mehta S, et al: Sildenafil and furosemide associated ototoxicity: consideration of drug-drug interactions, synergy, and broader clinical relevance. J Popul Ther Clin Pharmacol 2013; 20(2):e128-e131.
Keep reading about Furosemide Injection
Keep reading about Sildenafil
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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