A study of adverse drug reactions caused by first line anti-tubercular drugs used in Directly Observed Treatment, Short course (DOTS) therapy in western Nepal, Pokhara

Objective: To study the Adverse Drug Reactions occurring during DOTS therapy and to assess their causality, severity and predisposing factors. Method: Patients undergoing DOTS treatment during the 5 month study period (20th January to 20th June, 2005) at the Regional Tuberculosis Center (RTC) in Pokhara, Western Nepal were studied. Patients and/or patient party were interviewed to detect occurrence of any ADRs during their visit to the DOTS center. Causality and severity assessment were carried out as per the 'Naranjo scale' and 'modified Hartwig and Siegel scale' respectively. Statistical analysis (Chi square test) was done to determine the predisposing factors. Results: Totally 137 patients were studied among whom 54.74% (n=75) reported occurrence of ADRs. Total 29.33% of ADRs were reported by the age group 21- 30 years. Nearly half (49.33%) of the ADRs were reported by men and 33.33% were reported by the ethnic group of 'Gurungs'. Half (49.33%) of the patients were illiterate and 70.67% of the ADRs were classified as ADRs 'possibly' due to the suspected drugs and 93.33% were classified as 'mild (level 1)'. Isoniazid accounted for 49.3% of the ADRs. The most commonly reported ADR was tingling and burning sensation in hands and feet experienced by 32 (11.03%) patients. Conclusion: Occurrence of ADRs from antitubercular drugs was high in the population of Western Nepal. Further studies encompassing a wider population and covering different regions of Nepal are needed.