Treatment of disseminated Mycobacterium avium complex infection in AIDS with amikacin, ethambutol, rifampin, and ciprofloxacin. California Collaborative Treatment Group.

To determine the efficacy of combination drug therapy for disseminated Mycobacterium avium complex infection in patients with the acquired immunodeficiency syndrome (AIDS). Prospective, nonrandomized, before-after comparison. Outpatient clinics at three university medical centers. Seventeen patients with at least two consecutive blood cultures positive for M. avium complex who had not been previously treated with antituberculous medications. Fifteen of the seventeen patients completed at least 4 weeks of treatment. Patients received daily intravenous amikacin (7.5 mg/kg body weight) for the first 4 weeks plus the following oral medications for at least 12 weeks: ciprofloxacin, 750 mg twice daily; ethambutol, 1000 mg daily; and rifampin, 600 mg daily. The baseline geometric mean colony count from blood cultures decreased from 537/mL to 14/mL (P less than 0.001) after 4 weeks of therapy. The microbiologic suppression was sustained while on treatment and was associated with a decrease in systemic symptoms related to M. avium complex infection. Premature withdrawal from treatment (less than 12 weeks) occurred in 7 of 17 patients. The commonest reasons for early withdrawal were gastrointestinal intolerance and hepatic toxicity. Mycobacterial load and systemic symptoms in patients with AIDS and disseminated M. avium complex infection can be effectively reduced by a regimen containing amikacin, ethambutol, rifampin, and ciprofloxacin.