Nature, Magnitude and Risk Factors of Adverse Drug Reactions in Multidrug Resistant TB Patients in Eritrea

Abstract

Background: Adverse drug reactions (ADRs) of second-line anti-TB drugs have been reported as causes of poor treatment success of multi-drug resistant tuberculosis (MDR-TB). Spontaneous ADR reporting showed that (serious) ADRs related to the use of second-line anti-TBC drugs are common but these data are hampered by reporting bias. Objectives: To determine the nature, magnitude and risk factors of ADRs among all MDR-TB patients treated with second-line anti-TB drugs in Eritrea. Methods: A retrospective cohort study of all patients treated with second-line anti-TB drugs between June 2011 and 31 December 2016 in the Merhano MDR-TB hospital, the only hospital for MDR-TB care in Eritrea. Patients were eligible in case they had at least 2 month of follow-up data. The medical chart of all patients was reviewed to complete a Case Report Form collecting details on demographics, TBC treatment, comorbidity and type of adverse drug reactions. Results: Of the 152 eligible patients, a total of 650 ADRs were documented of which 56.3% were serious. Around 98% of patients developed at least one ADR and 92.6% of the patients experienced at least one serious ADR. Furthermore, 2.0% of the patients died because of these ADRs. Gastrointestinal upset, tachycardia, arthralgia, gouty arthritis and psychotic symptoms were the most debilitating ADRs, resulting in treatment interruptions in several patients. Preventability assessment (P-method) found the majority of the reactions (64.3%) to be non-preventable. Conclusion: Serious ADRs related to second-line anti-TB drugs were highly prevalent, rarely fatal and resulted in treatment interruptions in several patients.