Prevalence of ototoxicity in University of Benin Teaching Hospital, Benin city: a 5-year review.

BACKGROUND Ototoxicity refers to damage of the cochlea and/or vestibular apparatus from exposure to chemical substances, resulting in hearing impairment and or disequilibrium. An earlier study carried out at University of Benin Teaching Hospital (UBTH) in 2000 implicated chloramphenicol as the commonest ototoxic drug, followed by antimalarials (Quinine). AIM To identify the commonly implicated drugs in patients diagnosed with ototoxicity in Ear, Nose and Throat (ENT) Clinic of UBTH. MATERIALS AND METHODS One-hundred and three patients' case notes, diagnosed as having ototoxicity, between June 2005 and July 2010 at the ENT Clinic of UBTH were reviewed. Seventy-nine cases met the criteria for diagnosis of ototoxicity in this study. RESULTS Intravenous quinine (19.0%) was the commonest implicated drug, followed by oral chloroquine (6.3%), antihypertensive drugs (nifedipine, moduretics, artenolol [6.3%]), native herbal medicine (13.9%), chloramphenicol (1.3%), and unidentifiable drugs accounted for 53.2%. Most patients had severe to profound hearing loss at 4000 Hz and at 8000 Hz. Tinnitus was found in 84.8% of the patients. CONCLUSION Quinine is still the commonest implicated ototoxic drug in this part of the country.