Summary

Hydroxychloroquine was given orally to 50 patients with P. vivax infections, either in a single dose or in a one-day treatment of several doses. Both parasitemia and temperature were controlled on the average in less than 2 days, with no unfavorable effects noted. This study in Venezuela confirms observations by others that hydroxychloroquine exhibits antimalarial activity against P. vivax comparable to that of other 4-aminoquinolines but appears to be better tolerated.