Atovaquone and azithromycin for the treatment of babesiosis

Background Babesiosis is a tick-borne, malaria-like illness known to be enzootic in southern New England. A course of clindamycin and quinine is the standard treatment, but this regimen frequently causes adverse reactions and occasionally fails. A promising alternative treatment is atovaquone plus azithromycin. Methods We conducted a prospective, nonblinded, randomized trial of the two regimens in 58 subjects with non–life-threatening babesiosis on Nantucket, Massachusetts; on Block Island, Rhode Island; and in southern Connecticut. The subjects were assigned to receive either atovaquone (750 mg every 12 hours) and azithromycin (500 mg on day 1 and 250 mg per day thereafter) for seven days (40 subjects) or clindamycin (600 mg every 8 hours) and quinine (650 mg every 8 hours) for seven days (18 subjects). Results Adverse effects were reported by 15 percent of the subjects who received atovaquone and azithromycin, as compared with 72 percent of those who received clindamycin and quinine (P<0.001). The most ...