ADVERSE DRUG REACTIONS AMONG DRUG-RESISTANT TUBERCULOSIS TREATMENT: AN OBSERVATIONAL COHORT STUDY

Objective: Adverse drug reaction (ADR) is regarded as one of the major challenges in the treatment of drug-resistant tuberculosis (DR-TB). It can lead to non-compliance or interrupting treatment completion, which can contribute to avoidable morbidity, drug resistance, treatment failure, reduced quality of life, or mortality. Methods: A retrospective cohort study was conducted in the Ernakulam district of Kerala from 2016 to 2019. All DR-TB patients registered under the DR-TB center were enrolled in the study. Due to privacy and confidentiality HIV infected patients and patients below 12 y of age were excluded in this study and only the data with ADR reported by patients is collected from medical records. Results: Out of the total 146 patients, about 75 % of patients experienced at least one ADR during treatment, and a total of 208 ADRs were reported. Among all the ADRs, the most common ADR was gastritis (12.98%) followed by ototoxicity (10%) and vomiting (5.76%), etc. It was found that males (78.76%) within the age group 46-65 y exhibited more ADR than females. Some of the ADR requires drug withdrawal and replacement with other drugs and most of the patients also needed symptomatic treatment without modifying the treatment regimen. All ADR reported were collected and causality assessment was done via WHO and Naranjo scale. The majority of ADR belongs to the “probable” category in the WHO scale and Naranjo scale. The evaluation of the severity of ADR by using the Modified Hartwig and Siegel scale indicated that most of the ADR was of moderate level showing a 4b reaction. The study also assessed the preventability of ADR using the Schumock and Thornton preventability scale. Conclusion: Many of the ADRs were unidentified or not reported due to several reasons like milder ADR, patient lack of knowledge, Negligence of symptoms, unawareness of health providers, etc. Whereas the long-term treatment and diversities in age, gender, etc. were found as major contributors to ADR along with comorbidities. New drugs in combination with existing drugs created the potential for previously unnotified reactions. Pharmacovigilance should address the safety of therapy and identify ADRs, especially the serious ones with routine monitoring to prevent mortality, morbidity, and other negative outcomes.