G6PD and malaria: Among healthy patients with normal G6PD enzyme activity, neither tafenoquine nor primaquine caused a decline in hemoglobin level greater than 1.9 g per deciliter from baseline,8 and the observed declines in hemoglobin level in the GATHER trial were consistent with malaria and rehydration.23 The evaluation of hemolytic safety in the GATHER trial was limited, because female heterozygotes who had moderate G6PD enzyme deficiency could not be sufficiently recruited; only one such person met the study inclusion criteria despite an extension of the study recruitment window.