Impact of COVID-19 on adverse drug reactions in leprosy patients in Sri Lanka

The coronavirus disease (COVID-19) pandemic has disrupted health systems worldwide, potentially exacerbating treatment-related complications, such as adverse drug reactions, in the management of chronic diseases. Leprosy patients receiving multidrug therapy are particularly vulnerable to adverse drug reactions, and understanding the impact of the pandemic is critical for improving care. This study assessed trends in adverse drug reactions among patients with leprosy before and after the COVID-19 outbreak and forecasted future trends using time-series models. A retrospective descriptive study was conducted using data collected between 2016 and 2023 from the Central Leprosy Clinic at the National Hospital of Sri Lanka. Adverse drug reaction records were extracted from the National Leprosy Database and categorized into pre-COVID-19 (2016–2019) and post-COVID-19 (2020–2023) periods. Descriptive analyses and the Mann–Whitney U test were used to assess changes in adverse drug reaction patterns. The ARIMA and ETS models were applied to analyze temporal trends and forecast adverse drug reactions until 2030. The incidence of adverse drug reactions increased markedly in the post-COVID-19 period, peaking at 46 cases in 2023. The difference in adverse drug reactions between the pre- and post-pandemic periods was statistically significant (p = 0.03577). The ETS model outperformed the ARIMA model in terms of predictive accuracy (MAE: 0.84 vs. 8.00; RMSE: 1.05 vs. 12.29) and forecasted a steady rise in adverse drug reactions, reaching 32.33 by 2030. The findings indicate a significant increase in adverse drug reactions among patients with leprosy following the onset of the COVID-19 pandemic, highlighting potential disruptions in disease management and monitoring. The ETS model was more reliable for forecasting, highlighting its utility in guiding pharmacovigilance and resource-planning. Strengthening adverse drug reaction monitoring systems is essential to mitigate the long-term impact of pandemic-related healthcare disruptions on leprosy care.