Pharmacovigilance of Antitubercular Therapy in Tuberculosis

Background Adverse drug reactions (ADRs) to tuberculosis (TB) drugs are a significant concern for medical professionals and health authorities. Adverse events due to drug-resistant TB (DRTB) treatment are among the most important reasons for treatment interruption. Methods This study was an observational study conducted among patients diagnosed with TB (pulmonary/extrapulmonary) receiving antitubercular therapy (ATT) (first line/second-line drugs) irrespective of their age and gender. The patients who consented to participate, registered under National Tuberculosis Elimination Program (NTEP), Puducherry, during the study period from March 2020 to December 2020, were included in the study. The demographic details were recorded from the treatment card, and the participants were provided a diary to note down the adverse events. They were asked to report over the phone or during their visits to treatment centers for the first two months. During the follow-up (irrespective of their treatment phase [intensive/continuation]), the patients were assessed for symptoms and signs of common adverse events. Any adverse events reported by the patient were also recorded and analyzed for causality and severity. Results During the study period, 219 patients were included, of which 92 patients (42%) presented with adverse events. Among the patients with ADRs, 56.5% were males and 43.5% were females. The females were found to be at more risk than males for adverse events with the OR 1.871 (95% CI: 1.066-3.284). GI system was the most common body system involved (39%), followed by musculoskeletal system and skin disorders (24% and 21%), respectively. Most of the adverse events were latent in nature (60.9%), followed by sub-acute onset (28.3%) and acute events (6.5%). Maximum adverse events reported were mild to moderate (71.8%), followed by severe (18.5%). Most of the events were probable in nature (41.3%), and the definite category was 25% as per Naranjo's probability scale. Conclusion The current study shows the frequency of adverse events in patients receiving antitubercular drug therapy. The females were found to be at more risk than males for adverse events. It was found that the GI system was most affected as a known reaction to TB therapy followed by the musculoskeletal system. With more effective pharmacovigilance measures implementation, the adverse events being one of the factors for treatment interruption can be overcome.