Assessment of Short Term Chloroquine-Induced Ototoxicity in Malaria Patients

Abstract

Objective: To evaluate the effects of chloroquine phosphate on cochlear function using clinical and audiometric studies when administered in regular doses and in the recommended regimens, for the treatment of malaria. Study design and setting: Prospective, cohort, observational study, with convenience sampling, in a tertiary care hospital. Methodology: All subjects proved or presumed to be suffering from malaria and who received chloroquine phosphate treatment were inducted into the study. Base line clinical examination with detailed ear examination was carried out. Audiometric evaluation was carried out prior to treatment. All patients were treated with chloroquine phosphate tablets (1200mg) stat followed by 600 mg every 12 hours for 4 doses and paracetamol on a qrn basis. The study endpoints were development of ototoxic symptoms/signs or completion of the course as prescribed by the treating physician. Upon achieving any of the endpoints, the clinical examination and audiometric test battery was repeated. Results: Only 2 subjects showed a change in hearing thresholds on high frequency audiometry following administration of chloroquine. The Auditory Brainstem Response (ABR) and Otoaccoustic Emission (OAE) were also abnormal in these 2. All the others showed no change in clinical or audiometric profile following administration of chloroquine. Only one subject showed vestibular side effects in the form of giddiness and nystagmus which spontaneously resolved on completion of therapy. Conclusions: Chloroquine is not significantly ototoxic when administered in regular doses for treatment of uncomplicated malaria. The ototoxic effects of chloroquine which are rarely encountered are fully reversible.