The Impact of Medical Interventions for Reducing Ototoxicity During Treatment for Multi-drug Resistant Tuberculosis

Introduction: The impact of medical interventions for reducing ototoxicity requires focus in contexts where safe non-ototoxic alternative drugs are not yet available.

Objectives: The goal was to investigate the impact of medical intervention strategies for reducing the ototoxic effects of long-term use of aminoglycosides for the treatment of Multi-Drug Resistant Tuberculosis (MDR-TB) in adults at a rural hospital in the Eastern Cape, South Africa.

Methods: A retrospective record review with a control group design was used, with audiological and medical record reviews of all participants' files over a six-month period. A total of 86 participants (intervention group n=32 and control group n=54) were included. Descriptive and inferential statistics were used to analyze the data.

Results: Results revealed progressive hearing loss in both groups, with worsening of thresholds at each subsequent assessment session. The progression of the hearing loss, however, was much slower in the intervention group, with degree of hearing loss being more severe in the control group in the final session of assessment (36.78-71.74dB), when compared to the intervention group (33-44.39dB). Furthermore, the hearing loss in the intervention group remained in the high frequencies while that in the control group progressed to involve the lower frequencies on the audiogram. The most common medical intervention strategies employed in the current study were to reduce the dosage of the ototoxic drug (61%), with the daily dosage reduced to 800mg in 39% of participants, while the administration of the drug was reduced from daily to thrice weekly in 22% of participants.

Conclusions: The results reveal better hearing sensitivity over the treatment period in the intervention group when compared to the control group; thus suggesting that early medical strategies implemented had a significant preventive impact. Current findings are relevant to the audiological, medical and pharmaceutical fields, particularly within the South African context where resource constraints are a consideration in all treatment measures.