Management of Patients on Ototoxic Medications

Pre-Treatment Assessment

The American Thoracic Society recommends obtaining baseline audiometry before initiating aminoglycoside therapy in all patients who can be tested 1, 2
Patients should be screened for hearing or balance difficulties through direct patient questioning 3
Renal function should be checked (serum creatinine, BUN, or creatinine clearance) as impaired renal function increases ototoxicity risk 1
High-risk patients, including the elderly, those with pre-existing renal impairment, diabetes, immunocompromised state, or previous exposure to ototoxic drugs, should be identified 1
A review of medication history for concomitant ototoxic agents (loop diuretics, cisplatin, vancomycin) is necessary to avoid potential interactions 4

Serum drug level monitoring is crucial, with target trough levels <5 mg/L for amikacin 1, 5
Peak and trough levels should be measured to ensure therapeutic efficacy while avoiding toxic accumulation 1
The American Thoracic Society recommends performing monthly audiometry until aminoglycoside treatment ceases 1, 2
Ototoxicity is defined as 20 dB loss from baseline at any one test frequency OR 10 dB loss at any two adjacent test frequencies 1, 5

The American Thoracic Society recommends discontinuing the aminoglycoside immediately if ototoxicity is detected on audiogram 1, 5, 2
Alternative options include reducing dosing frequency if discontinuation is not feasible, though hearing loss already occurred is likely permanent 1, 5
Patients should be instructed to stop treatment immediately and inform their prescriber if they develop tinnitus, vertigo, loss of balance, hearing loss, or auditory disturbances 1, 2, 5

The American Journal of Kidney Diseases recommends reducing dose and/or extending dosing interval when GFR <60 mL/min/1.73m² 4
Dosing should be based on ideal body weight in obese patients, not actual weight 1
Serum levels should be monitored closely as accumulation risk increases with renal dysfunction 1

Elderly patients are at higher risk for both nephrotoxicity and ototoxicity, and should be monitored more closely with consideration of dose reduction 1, 4
Patients with pre-existing hearing loss should be informed about the potential for further deterioration with macrolides, which is typically reversible 3
Aminoglycosides should be avoided in the second or third trimester of pregnancy due to the risk of vestibular or auditory nerve damage to the fetus 1, 5

Multiple aminoglycosides should never be combined due to increased toxicity risk and no clinical benefit 1, 5
Concurrent loop diuretics should be avoided as they potentiate ototoxicity 1, 4
Audiometry should not be delayed until symptoms appear, as damage may already be irreversible 1
Patient-reported symptoms alone are not reliable for monitoring, and objective audiometry is essential 1, 2

For patients over 59 years of age or with stage 3 CKD, the American Thoracic Society recommends reducing the dose to 10 mg/kg per day (maximum 750 mg) 6, 7
In renal insufficiency, the American Thoracic Society suggests maintaining the 12-15 mg/kg dose but reducing frequency to 2-3 times weekly rather than daily to preserve concentration-dependent killing while avoiding accumulation 6, 7
The American Thoracic Society advises against reducing the milligram dose below 12-15 mg/kg when extending intervals, as smaller doses may reduce efficacy by failing to achieve adequate peak concentrations 6, 7

For Pseudomonas infections, the American Thoracic Society recommends considering 2-3 months of intermittent amikacin (2-3 times weekly) in combination with other agents for extensive or drug-refractory disease 8

The American Thoracic Society warns against concurrent use of loop diuretics (furosemide, ethacrynic acid) as they potentiate ototoxicity 6