The current gold standard for radical cure of P. vivax malaria in many areas of the world is chloroquine (CQ) for clearance of the acute parasitemia immediately followed by primaquine (PQ) to clear the liver stages of the parasite and prevent disease relapse. The 8-AQ class of drugs, including PQ, is hemolytic in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The current study will identify a dose of TQ within the target efficacious dose range that has a hemolytic effect similar to or less than PQ 15 mg OD x 14 days (i.e. ≤ 25-30% hemoglobin decline in WHO class III G6PD-deficient subjects).