RANDOMIZED, CONTROLLED, DOUBLE-BLIND TRIAL OF DAILY ORAL AZITHROMYCIN IN ADULTS FOR THE PROPHYLAXIS OF PLASMODIUM VIVAX MALARIA IN WESTERN THAILAND

We assessed the prophylactic efficacy of azithromycin (250 mg/day) against malaria in 276 adults in western Thailand in a randomized double-blind placebo-controlled trial. After antimalarial suppressive treatment volunteers were randomized in a 2:1 ratio to either the azithromycin or placebo respectively. Study medication was given for an average of 74 days. The azithromycin group (n = 179) had five endpoint parasitemias (1 Plasmodium vivax and 4 P. falciparum) and the placebo group (n = 97) had 28 endpoint parasitemias (21 P. vivax 5 P. falciparum and 2 mixed infections). Adverse events and compliance and withdrawal rates were similar in both groups. The protective efficacy (PE) of azithromycin was 98% for P. vivax (95% confidence interval [CI] = 88-100%). There were too few cases to reliably estimate the efficacy of azithromycin for P. falciparum (PE = 71% 95% C = -14-94%). We conclude that daily azithromycin was safe well-tolerated and had a high efficacy for the prevention of P. vivax malaria. (authors)