Efficacy of Gentamicin plus Doxycycline versus Streptomycin plus Doxycycline in the Treatment of Brucellosis in Humans

Abstract

Background. In the treatment of human brucellosis, antibiotic regimens containing an aminoglycoside are reportedly associated with fewer relapses. Methods. This prospective, randomized study employed doxycycline (100 mg administered orally twice daily for 45 days) in combination with either streptomycin (1 g administered intramuscularly daily for 14 days; the DS regimen) or gentamicin (5 mg/kg per day administered intramuscularly for 7 days; the DG regimen). Efficacy of treatment was determined by rates of failure or relapse with a follow-up period of 1 year. Results. Ninety-seven patients with a mean age (± standard deviation [SD]) of 33.74 ± 15.47 years and 94 patients with the a mean age (±SD) of 36.2 ± 14.14 years were treated with regimens DG and DS, respectively (P = .277). The clinical manifestations in both groups of patients were similar with the exception of sweating, which was more common in the DG group (P = .04). Three (3.2%) of the patients in the DS group and 3 (3.1%) of patients in the DG group experienced relapse (difference, 0.1%; 95% confidence interval [CI], -4% to 5%; P = 1.0). Overall, 7 (7.4%) of the patients in the DS group and 5 (5.2%) of the patients in the DG group experienced failure of therapy or relapse (difference, 2.2%; 95% CI, -4.5% to 8.9%; P = .563). The actuarial probability for relapse at 12 months after completion of therapy was 4.3% in the DS group and 2.1% in the DG group (difference, 2.2%; 95% CI, -2.8% to 7.2%). Conclusions. The combination of oral doxycycline for 45 days plus intramuscular gentamicin for 7 days is equally as effective as traditional therapy using doxycycline for 45 days plus streptomycin for 14 days.