Tolerability of twice-weekly rifabutin-isoniazid combinations versus dailyisoniazid for latent tuberculosis in HIV-infected subjects: a pilot study

The tolerability of and adherence to intermittent shortterm rifabutin-isoni azid preventive treatment was assessed in subjects dually infected with Myc obacterium tuberculosis and the human immunodeficiency virus (HN). In a ran domised, open-label, phase II pilot study, 44 subjects received either rifa butin 300 mg and isoniazid 750 mg twice weekly for 3 months (group A, n = 1 6) or the same regimen with rifabutin at 600 mg (group B, n = 14), or isoni azid 300 mg/day for 6 months (group C, n = 14). Three, two and four subject s in groups A, B, and C, respectively, did not complete their treatment (on e case of flu-like syndrome in group B; one methadone withdrawal syndrome i n group A; and patient decision in two cases in group A and four in group C ). Overall, adverse events were reported by four, nine, and seven subjects in groups A, B and C, respectively. Intermittent combined rifabutin + isoni azid for 3 months had lower default rates than daily standard isoniazid for 6 months. The regimen with rifabutin at 300 mg dose compared favourably to standard isoniazid, and warrants larger efficacy studies to assess its rol e for the prevention of latent tuberculosis in HN-infected subjects.