Furosemide Injection and Ethacrynic Acid: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ethacrynic Acid
Furosemide Injection
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
An increased risk of ototoxicity
Interaction Deep Dive
Ototoxicity has been well documented following the use of ethacrynic acid in concentrations of 30 and 50 mg/kg, and in concentrations of 10 mg/kg if the doses were repeated in two hours4. Both temporary and permanent deafness have been reported to occur following the use of ethacrynic acid 5. Likewise, permanent hearing impairment has been caused by the administration of furosemide, presumably from furosemide-induced stria damage 3. Avoid concurrent use of furosemide and ethacrynic acid due to the risk of ototoxicity. Cases of tinnitus and reversible or irreversible hearing impairment and deafness have been reported with furosemide. Reports usually indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, the use of higher than recommended doses, hypoproteinemia or concomitant therapy with ethacrynic acid. If the physician elects to use high-dose parenteral therapy, controlled intravenous infusion is advisable (for adults, an infusion rate not exceeding 4 mg furosemide per minute has been used) 21.
Why it happens (mechanism)
Additive or synergistic toxic effects in the stria vascularis
Literature reports
2 reports — tap to read
a) Cases of tinnitus and reversible or irreversible hearing impairment and deafness have been reported with furosemide. Reports usually indicate that furosemide ototoxicity is associated with rapid injection, severe renal impairment, the use of higher than recommended doses, hypoproteinemia or concomitant therapy with aminoglycoside antibiotics, ethacrynic acid, or other ototoxic drugs 21.
b) Ototoxicity has been well documented following the use of ethacrynic acid in concentrations of 30 and 50 mg/kg, and in concentrations of 10 mg/kg if the doses were repeated in two hours 4. Both temporary and permanent deafness have been reported to occur following the use of ethacrynic acid 5. Likewise, permanent hearing impairment has been caused by the administration of furosemide, presumably from furosemide-induced stria damage 3.
Common questions
Can I take Furosemide Injection and Ethacrynic Acid together?
An increased risk of ototoxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Furosemide Injection and Ethacrynic Acid interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Furosemide Injection or Ethacrynic Acid 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 (5)
- Product Information: LASIX® ONYU subcutaneous injection, furosemide subcutaneous injection. SQ Innovation, Inc (per manufacturer), Burlington, MA, 2025. DailyMed
- Product Information: FUROSCIX(R) subcutaneous injection, furosemide subcutaneous injection. scPharmaceuticals Inc (per FDA), Burlington, MA, 2025. DailyMed
- Quick CA & Hoppe W: Permanent deafness associated with furosemide administration. Ann Otol Rhinol Laryngol 1975; 84:94-101. PubMed
- Prazma J, Thomas WG, Fischer ND, et al: Ototoxicity of the ethacrynic acid. Arch Otolaryngol 1972; 75:448-456. DOI
- Mathog RH & Matz GJ: Ototoxic effects of ethacrynic acid. Ann Otol Rhinol Laryngol 1972; 81:871-875. PubMed
Keep reading about Ethacrynic Acid
Keep reading about Furosemide Injection
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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist