Deafness 
When a medication damages the inner ear — the part of the ear responsible for receiving/sending sounds and controlling balance — it's called ototoxicity or "ear poisoning." The degree of damage to the ear depends on what type of drug is taking, how much, and for how long. Some people may have no or very minimal hearing loss and "ringing in the ears" (tinnitus), while others may experience major problems with balance and/or profound hearing loss (deafness). Factors affecting drug-induced deafness include dose, duration of therapy, concurrent renal failure, infusion rate, lifetime dose, co-administration with other drugs having ototoxic potential, and genetic susceptibility.
