[Rifabutine in the treatment of mycobacterial infections resistant to rifampicin. Preliminary results. Group for the Study and Treatment of Resistant Mycobacterial Infections (GETIM)].

Three treatment protocols using rifabutine for mycobacterial infections resistant to rifampicin were prepared by a study group (GETIM) and were accepted by the ethical committee concerned. A prospective study has been carried out since April 1986. Thirty-five cases of tuberculosis with bacilli resistant to rifampicin received daily treatment with 5 to 7 mg/kg of rifabutine combined with several other drugs which were still active in vitro. Sixteen cases of M. xenopi infection occurred in individuals without apparent immune deficiency and they were treated with a daily combination of 5 to 7 mg/kg of rifabutine, 20 mg/kg of ethambutol, 3 to 5 mg/kg of isoniazid and 400 mg of ofloxacin (or 800 mg of pefloxacin). Twenty-one cases of M. avium-intracellulare infection, also in patients without any evident immune deficiency, and fifty-nine cases in patients suffering from the acquired immunodeficiency syndrome (AIDS), were treated with a similar combination in which the fluoroquinolone was replaced with 100 mg of clofazimine. During the first three months of treatment there were few major problems of toxicity or acceptability in the different combinations of drugs with the exception of three cases of leukopenia with thrombocytopenia. The proportion of negative cultures on the third month was 8 out of 24 (33%) for the cases of pulmonary tuberculosis and 10 out of 13 (77%) for the cases of M. xenopi infection, and 6 out of 11 (55%) and 9 out of 13 (69%), respectively, for infections by M. avium-intracellulare in subjects without immune deficiency and in subjects suffering from AIDS.(ABSTRACT TRUNCATED AT 250 WORDS)