SUCCESSFUL DOUBLE-BLINDED, RANDOMIZED, PLACEBO-CONTROLLED FIELD TRIALOF AZITHROMYCIN AND DOXYCYCLINE AS PROPHYLAXIS FOR MALARIA IN WESTERNKENYA

Azithromycin prevents malaria in animal models and early clinical tria ls. We determined the prophylactic efficacy of three antibiotic regime ns given for 10 weeks (azithromycin, 250 mg daily; azithromycin, 1,000 mg weekly; and doxycycline, 100 mg daily) relative to that of placebo for 232 adult volunteers residing in apt area of intense malaria tran smission. Any confirmed parasitemia during the study was considered a prophylactic failure. Two hundred thirteen volunteers (92%) completed the study, The prophylactic efficacies were as follows: daily azithrom ycin, 82.7% (95% confidence interval [CI], 68.5%-91.1%); weekly azithr omycin, 64.2% (95% CI, 47.1%-77.1%); and daily doxycycline, 92.6% (95% CI, 79.9%-97.5%). AU regimens were well tolerated, We concluded that both 100 mg of doxycycline and 250 mg of azithromycin, given daily, we re effective as prophylaxis for malaria in this setting. If studies wi th nonimmune volunteers confirm these results for semi-immune voluntee rs, a daily azithromycin regimen may have special utility for individu als with contraindications to treatment with doxycycline or other anti malarial agents.