Alarming levels of ototoxicity among multidrug resistant tuberculosis patients on intensive phase of treatment at specialist treatment centers in South Western, Nigeria

Abstract

Management of multi drug resistant tuberculosis (MDR-TB) patients remains a challenge in the control of tuberculosis worldwide. MDR-TB patients require long term treatment with drugs that cause various adverse effects especially ototoxicity associated with aminoglycoside. Current treatment guidelines still include aminoglycosides use especially in developing countries. However, there is dearth of information regarding ototoxic effects of MDR-TB treatment in Nigeria. This study explored the prevalence of ototoxicity and associated factors among MDR-TB patients during the intensive phase of treatment. A retrospective review of records of 383 MDR-TB patients admitted at two specialist treatment centers in South West Nigeria from 2012-2017 was conducted. Using a structured proforma, socio demographic characteristics and clinical history were extracted. Ototoxicity was assessed as any abnormality reported from a pure tone audiometry. Discrete data were summarized with frequencies, proportions while bivariate analysis was done using chi square test to identify associated factors. Multivariate analysis was performed to identify independent predictors of ototoxic effects. All statistical significance was set at 5%. Out of the 383 records extracted, only 143(37.3%) had audiometry performed. Of these 143 MDR-TB patients, mean age was 36.2 ± 11.3 years and prevalence of any ototoxic effect was 72.7 %. This was higher in older age groups, females and those underweight. (p>0.05) Patients who did not sputum convert at the end of treatment and HIV co infected had higher proportions with ototoxic effects (p < 0.05). However, on multivariate analysis only age remained a significant independent predictor of ototoxic effect (AOR: 8.7; 95% CI: 1.4-52.2). Adverse effects are main deterrents to compliance and completion of long term treatment regimen. High rates of ototoxic effects as seen in this study could affect successful management of MDR-TB patients. Auditory monitoring and rehabilitation should be recommended for MDR-TB patients even after completion of the intensive phase of treatment. Key words: Aminoglycoside ototoxicity, drug resistant tuberculosis, Nigeria.