Adverse drug reactions associated with first line anti-tubercular drugs, their prevalence and causality assessment in patients on Directly Observed Treatment Short-course (DOTS) in a tertiary care hospital

Background: Treatment of tuberculosis involves giving multiple drugs to the patient which is done to prevent development of resistance besides targeting all bacterial sub-populations. The objective of the present study was to find out the adverse drug reactions (ADRs) of the first line anti-tubercular drugs and to calculate prevalence and causality of these drugs.Methods: The study was conducted by the Department of Pharmacology, Government Medical College, Srinagar in association with the department of Chest medicine. All patients of tuberculosis on directly observed treatment-short course (DOTS) of either sex or age group were enrolled. An assessment of the causality and allocation of ADRs was done using Naranjo’s monitoring scale and WHO-UMC scale.Results: A total of 57 ADRs with 13 different types were observed in 164 patients, with an overall prevalence of about 34.7%. Thirty seven (64.9%) ADRs were categorized as having a ‘probable’ causal relationship while 17 (29.8%) was categorized as ‘possible’ as per the Naranjo’s scale. As per the WHO-UMC monitoring scale fifty two (91.2%) were categorized as ‘possible’ while three (5.3%) were categorized as ‘certain’.Conclusions: Occurrence of ADRs generally results in non-adherance. Timely detection of ADRs through an effective pharmacovigilance programme is the need of hour. The establishment of an active pharmacovigilance centre which was set up in our institution has paved the way to improve the quality of patient care by ensuring safer use of drugs and has helped us to identify and report the various ADR’s encountered