Mycobutin (rifabutin) is a new spiropiperidylrifamycin with broad spectrum antimycobacterial activity against atypical mycobacteria, particularly Mycobacterium avium complex (MAC), and many rifampicin-resistant strains of Mycobacterium tuberculosis. Over 300 patients have been treated at several centres in the UK with antimycobacterial, mycobutin-containing regimens, on an open, named-patient (compassionate) basis prior to product licence application. An outcome surveillance study using standardized case report forms was set up to monitor safety and outcome variables. Data was recorded at baseline, during treatment and "off treatment" and included demography, clinical assessments (weight, temperature, presence of night sweats and/or diarrhoea, adverse events, concurrent disease), microbiological assessments (AFB positivity, culture positivity), haematological assessments (including CD4+ count), biochemical assessments, concurrent medication and bacteriological and clinical outcome cured, improved, deteriorated, no change, death). An interim analysis has been performed on 232 patients (M 198, F 34). At baseline mean (SD) age was 38 (13.8) years, mean (SD) weight was 56.2 (12.8) kg. Of the 232 patients, 188 (M 183, F 5) had mycobacterial infections secondary to AIDS (the others included patients treated for tuberculosis or Crohn's Disease) The usual dose of rifabutin ranged from 300-600 mg per day. At the time of analysis the outcome was known in 108 patients; the median duration of therapy was 81.5 days (range 1-945 days); 35 patients had completed therapy, 70 had discontinued therapy because of adverse events (9), lack of efficacy (7), other reasons (14) and death (40). Adverse events reported were rash (7), nausea/vomiting (1), neutropenia (1), anaemia (1), jaundice (1) and grand-mal seizure (1). CONCLUSION: Although a full analysis is still in progress the interim report does not indicate any safety hazard of the use of Mycobutin in the treatment of AIDS associated mycobacterial infections.

*Drugs, Investigational/THERAPEUTIC USE *Mycobacterium Infections/DRUG THERAPY *Rifamycins/THERAPEUTIC USE

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