Currently, the only treatment licensed to prevent Plasmodium vivax relapses through killing hypnozoites is primaquine, which frequently causes gastrointestinal side effects, poses a risk of hemolysis in people with G6PD deficiency [2, 7], and has decreased efficacy in people with mutations in the cyp2d6 gene that encodes cytochrome P450 2D6 [8]. Here, CYP2D6 is linked to G6PD deficiency.