Lasix Ototoxicity
Yes, Lasix (furosemide) can cause ototoxicity, including tinnitus, reversible or irreversible hearing impairment, and deafness, particularly when administered rapidly intravenously, at high doses, in patients with renal impairment, hypoproteinemia, or when combined with other ototoxic drugs like aminoglycosides. 1
Risk Factors for Furosemide Ototoxicity
The FDA drug label explicitly warns that furosemide ototoxicity is associated with several specific conditions 1:
- Rapid IV injection (infusion rates should not exceed 4 mg/min in adults)
- Severe renal impairment
- Higher than recommended doses
- Hypoproteinemia (e.g., nephrotic syndrome)
- Concomitant use with aminoglycoside antibiotics, ethacrynic acid, or other ototoxic drugs
Multiple guidelines confirm that loop-inhibiting diuretics (furosemide, ethacrynic acid) significantly increase the risk of ototoxicity when combined with aminoglycosides like streptomycin, amikacin, and kanamycin 2, 3, 2. This combination should be avoided except in life-threatening situations 1.
Clinical Characteristics
The hearing loss from furosemide is typically temporary but can become permanent, particularly with the risk factors listed above 1. The mechanism involves:
- Disruption of the stria vascularis in the cochlea
- Decreased endolymphatic potential
- Possible ischemia-induced blood-cochlea barrier disruption 4
High-dose furosemide (>6 mg/kg/day) should not be given for longer than 1 week, and infusions should be administered over 5-30 minutes to avoid hearing loss 5.
Special Populations at Higher Risk
Premature infants and young children are particularly vulnerable. A quality improvement study demonstrated that slow IV administration of furosemide eliminated permanent hearing loss in infants undergoing single-ventricle cardiac surgery (dropping from 17% to 0%) 6. However, prolonged exposure (≥28 days) in premature infants showed a trend toward abnormal hearing screens, though not statistically significant 7.
Elderly patients receiving aminoglycosides have increased ototoxicity risk when combined with furosemide 2, 8.
Monitoring Recommendations
When furosemide is used, particularly at high doses or with aminoglycosides:
- Baseline audiometry should be performed before initiating therapy
- Monthly questioning about auditory or vestibular symptoms during treatment 2, 3
- Repeat audiometry if symptoms of eighth nerve toxicity develop
- Avoid rapid IV boluses—use controlled infusion rates
Drug Interactions
Beyond aminoglycosides, furosemide increases ototoxicity risk with:
- Cisplatin 9, 1
- Ethacrynic acid (should not be used concomitantly) 1
- Sildenafil (case reports suggest synergistic ototoxicity, especially with CYP3A4 inhibitors) 10
Clinical Pitfalls
Common mistake: Administering furosemide as rapid IV push in critically ill patients with renal dysfunction. This combination dramatically increases ototoxicity risk. Always use slow infusion rates and dose-adjust for renal function.
Important caveat: Even very high-dose continuous infusions (≥40 mg/h) may not cause ototoxicity when administered properly as controlled infusions, with one case series showing no ototoxicity events 11. The key is rate of administration, not just total dose.
The potentiation of ototoxicity is particularly concerning in patients with hypoproteinemia (e.g., nephrotic syndrome), where furosemide's effect may be weakened but ototoxicity paradoxically potentiated 1.