EFFICACY AND SAFETY OF RIFABUTIN IN THE TREATMENT OF PATIENTS WITH NEWLY-DIAGNOSED PULMONARY TUBERCULOSIS

The efficacy and safety of rifabutin (RBT) and rifampicin (RMP) were c ompared in 298 patients with newly diagnosed pulmonary tuberculosis. I n the initial 8-wk phase, all patients received isoniazid 400 mg/d, et hambutol 1200 mg/d, and pyrazinamide 2 g/d and were randomly allocated to receive either RMP 600 mg/d or RBT 300 mg/d. In the 16-wk continua tion phase, patients received intermittent treatment (twice weekly) wi th isoniazid 600 mg/d, ethambutol 2400 mg/d and either RMP 600 mg/d or RBT 300 mg/d. Two hundred twenty-five (RMP = 118; RBT = 107) patients completed the 24-wk treatment period (evaluable patient population). Bacteriologic conversion rates in the RMP and RBT groups were 87.7 ver sus 92.0% at Week 8, 99.1 versus 99.0% at Week 12, 93.5 venus 93.8% at Week 24, and 89.8 versus 95.3% at the last valid observation. The mea n time to first bacteriologic conversion was 14.1 wk in the RMP group and 14.3 wk in the RBT group. None of these differences was significan t. Adverse events were reported by four patients (five events) in the RMP group and six patients (six events) in the RBT group. Those events thought to be associated with RMP were increased SCOT and leucopenia and, with RBT, increased SGOT and thrombocytopenia. Two hundred four p atients entered the follow-up phase, and, of these, 95 (RMP = 49; RBT = 46) completed the scheduled 24-mo period. The overall rate of relaps e was 3.8% (4/106) for the RMP group and 5.1% (5/98) for the RBT group . These differences were not significant. All relapsed patients, excep t for two who could not be traced, were successfully retreated. We con clude that the efficacy and tolerability of RBT is equivalent to that of RMP in the treatment of newly diagnosed uncomplicated tuberculosis, and that RBT can be effectively administered in a part-daily, part-in termittent dosage schedule.