Acquired Rifamycin Resistance with Twice-Weekly Treatment of HIV-related Tuberculosis

Rationale: Rifabutin was recommended in place of rifampin during treatment of HIV-related tuberculosis (TB) to facilitate concomitant potent antiretroviral therapy, but this approach has not been evaluated in a prospective study.Objective: To evaluate the activity of intermittent rifabutin-based therapy.Methods: Patients with culture-confirmed TB were treated under direct supervision with 2 mo of rifabutin, isoniazid, pyrazinamide, and ethambutol (given daily, thrice-weekly, or twice-weekly per the local tuberculosis control program), followed by 4 mo of twice-weekly rifabutin plus isoniazid.Measurements: Culture-positive treatment failure or relapse.Main Results: A total of 169 eligible patients were enrolled. Most had advanced HIV disease; the median CD4 cell count and HIV-RNA level were 90 cells/mm3 (interquartile range, 35–175) and 5.3 log10 copies/ml (interquartile range, 4.8–5.7), respectively. Nine (5.3%) patients had culture-positive treatment failure (n = 3) or relapse (n = 6). Eight of these nin...