First-line tuberculosis treatment with double-dose rifampicin is well tolerated

OBJECTIVE: To compare the occurrence of unfavourable treatment and safety outcomes of double-dose rifampicin (RMP; 20 mg/kg/d, intervention) with standard dose (10 mg/kg/d, control) in a first-line tuberculosis (TB) treatment regimen for smear-positive TB patients in Bangladesh.DESIGN: This was a randomised clinical trial. The primary efficacy and safety endpoints were the occurrence of an unfavourable treatment outcome (death, failure, relapse or loss to follow-up) and the occurrence of any serious drug-related adverse event (SAE).RESULTS: In primary efficacy analysis, among 343 control and 347 intervention patients, respectively 15.5% and 11.8% had an unfavourable outcome. In safety analysis, among 349 intervention and 352 control patients, respectively 4.3% and 2.6% experienced an SAE. These differences were not significant. There was a significantly lower occurrence of SAEs, explained by a lower occurrence of hepatic toxicity, in a RMP double-dosed but erroneously HZE (isoniazid+pyrazinamide+ethambutol) under-dosed subgroup.CONCLUSIONS: Our findings show that there is no statistically significant difference in terms of efficacy and safety between standard and double-dose RMP. An accidental finding (related to dosage levels of the standard regimen) suggests that high-dose RMP is potentially a lesser cause of hepatotoxicity. Larger trials with more power, or trials with at least a triple-dose might be needed to clearly see the effect of high-dose RMP on unfavourable outcomes.