Precautions for Ototoxic Medications in Patients with Pre-Existing Hearing Loss

Pre-Treatment Assessment

The American Thorax Society recommends obtaining baseline audiometry in all patients who can be tested before initiating aminoglycoside therapy, and screening for hearing or balance difficulties through direct questioning 1, 2
Patients with pre-existing hearing loss should be explicitly counseled about the risk of further irreversible hearing damage, and have their renal function checked (serum creatinine, BUN, or creatinine clearance) as impaired renal function dramatically increases ototoxicity risk 1
The American Thorax Society suggests reviewing medication history for concomitant ototoxic agents including loop diuretics, cisplatin, and vancomycin 1

Patients with pre-existing hearing or balance difficulties must be informed that aminoglycoside-induced hearing loss is irreversible, and this differs from macrolide-associated ototoxicity, which is almost always reversible 2, 3, 4
The American Thorax Society recommends documenting that the patient understands the risk of permanent worsening of their hearing 1, 2

The American Thorax Society suggests performing monthly audiometry until aminoglycoside treatment ceases, and defining ototoxicity as 20 dB loss from baseline at any one test frequency OR 10 dB loss at any two adjacent test frequencies 1, 3, 5
Patient-reported symptoms alone are unreliable; objective audiometry is essential, and final audiometry review should be offered 2 months after the final dose 1, 5

The American Thorax Society recommends discontinue the aminoglycoside immediately if ototoxicity is detected on audiogram, and instruct patients to stop treatment immediately and contact their prescriber if they develop tinnitus, vertigo, loss of balance, hearing loss, or auditory disturbances 1, 3

The American Thorax Society suggests reducing dose and/or extend dosing interval when GFR <60 mL/min/1.73m², and monitoring serum levels closely as accumulation risk increases dramatically 1, 5
For streptomycin: 12-15 mg/kg two to three times weekly in renal failure, and age >59 years: reduce streptomycin dose to 10 mg/kg daily (maximum 750 mg daily) 1, 5

The American Thorax Society recommends never combining multiple aminoglycosides due to increased toxicity without clinical benefit, and avoiding concurrent loop diuretics as they potentiate ototoxicity 1
Avoid concurrent nephrotoxic drugs (capreomycin, cephalosporins, ciclosporin, colistimethate, tacrolimus), and do not delay audiometry until symptoms appear—damage may already be irreversible 1, 5