Adverse reactions of anti-tuberculosis drugs in hospitalized patients: incidence, severity and risk factors

BACKGROUND: Tuberculosis (TB) has been a common chronic infectious disease in human communities. Besides disease-related complications, there could be serious adverse reactions due to anti-tuberculosis (anti-TB) drug therapy. OBJECTIVES: To assess the incidence and severity of adverse drug reactions (ADRs) induced by anti-TB drugs. To determine possible covariates associated with detected ADRs. METHODS: All patients with respiratory TB admitted to a teaching hospital who received anti-TB drugs during the research period entered the study and were monitored for ADRs. Socio-demographic and medical history of patients were used as independent covariates. The relationship between independent covariates with frequency and severity of ADRs was analysed using multivariate logistic regression. Preliminary analyses of the Mann-Whitney, Chi-square, Kruskal-Wallis and the Fisher's exact tests were applied to determine factors unlikely associated with the independent variables. RESULTS: Among 204 patients admitted, there were 92 patients (45.1%) with ADRs induced by anti-TB drugs. Patients with a previous history of anti-TB drugs usage (OR = 5.81, 95% confidence interval [95%CI]: 1.31-25.2), patients with a history of drug allergy (OR = 6.68, CI: 1.28-36.2), those from Afghani ethnic (OR = 4.91, 95%CI: 1.28-18.30) as well as smoker patients with concurrent diseases (OR = 19.67, CI: 1.24-341.51) had a higher rate of ADR incidence. Being female (OR = 1.63, 95%CI: 1.96-36.40) and having previous history of ADR (OR = 17.46, 95%CI: 1.96-20.42) were identified as risk factors. CONCLUSION: Anti-TB drugs could cause severe and frequent adverse effects. Females, those with a previous history of ADRs to anti-TB drugs and Afghani patients, should be considered as high-risk groups.