We conducted a study to compare the safety and tolerability of anti-relapse drugs elubaquine and
primaquine against
Plasmodium vivax malaria. After standard
therapy with
chloroquine, 30 mg/kg given over 3 days, 141 patients with P. vivax
infection were randomized to receive
primaquine or elubaquine. The 2 treatment regimens were
primaquine 30 mg once daily for 7 days (group A, n = 71), and elubaquine 25 mg once daily for 7 days (group B, n = 70). All patients cleared
parasitemia within 7 days after
chloroquine treatment. Among patients treated with
primaquine, one patient relapsed on day 26; no relapse occurred with elubaquine treatement. Both drugs were well tolerated. Adverse effects occurred only in patients with
G6PD deficiency who were treated with
primaquine (group A, n = 4), whose mean hematocrit fell significantly on days 7, 8 and 9 (P = 0.015, 0.027, and 0.048, respectively). No significant change in hematocrit was observed in patients with
G6PD deficiency who were treated with elubaquine (group B, n = 3) or in patients with normal G6PD. In conclusion, elubaquine, as anti-relapse
therapy for P.
vivax malaria, was as safe and well tolerated as
primaquine and did not cause clinically significant
hemolysis.