Use of rifabutin in the treatment of pulmonary tuberculosis

This article reviews recent studies conducted outside the United States assessing the efficacy and safety of rifabutin in the treatment of tuberculosis (TB) in HIV-infected patients, in patients with newly diagnosed TB, and in patients with multidrug-resistant TB. A 6-month pilot study of 50 Ugandan patients with TB associated with HIV infection showed that rifabutin and rifampin were similarly effective with regard to conversion of sputum-smear findings (sputum conversion) and in bringing about clinical and radiologic improvement. Compared with rifampin, rifabutin showed potential for reducing the time to sputum conversion for these patients. Multicenter studies in five countries compared two rifabutin dosages (150 mg/d and 300 mg/d) with rifampin as part of a combination regimen for treatment of newly diagnosed TB in 935 patients. Rifabutin compared favorably with rifampin in sputum conversion; administration of 150 mg/d of rifabutin yielded good results and the fewest adverse effects. The use of rifabutin by 270 patients in five countries who had multidrug-resistant TB (similar to 90% of isolates tested were resistant to rifampin and isoniazid) was assessed in another study. For the majority of these patients, signs and symptoms diminished; one-third had bacteriologic conversions.