Hemolytic Dynamics of Weekly Primaquine Antirelapse Therapy Among Cambodians With Acute Plasmodium vivax Malaria With or Without Glucose-6-Phosphate Dehydrogenase Deficiency.
Taylor WRJ., Kheng S., Muth S., Tor P., Kim S., Bjorge S., Topps N., Kosal K., Sothea K., Souy P., Char CM., Vanna C., Ly P., Khieu V., Christophel E., Kerleguer A., Pantaleo A., Mukaka M., Menard D., Baird JK.
BACKGROUND:Hemoglobin (Hb) data are limited in Southeast Asian glucose-6-phosphate dehydrogenase (G6PD) deficient (G6PD-) patients treated weekly with the World Health Organization-recommended primaquine regimen (ie, 0.75 mg/kg/week for 8 weeks [PQ 0.75]). METHODS:We treated Cambodians who had acute Plasmodium vivax infection with PQ0.75 and a 3-day course of dihydroartemisinin/piperaquine and determined the Hb level, reticulocyte count, G6PD genotype, and Hb type. RESULTS:Seventy-five patients (male sex, 63) aged 5-63 years (median, 24 years) were enrolled. Eighteen were G6PD deficient (including 17 with G6PD Viangchan) and 57 were not G6PD deficient; 26 had HbE (of whom 25 were heterozygous), and 6 had α-/β-thalassemia. Mean Hb concentrations at baseline (ie, day 0) were similar between G6PD deficient and G6PD normal patients (12.9 g/dL [range, 9‒16.3 g/dL] and 13.26 g/dL [range, 9.6‒16 g/dL], respectively; P = .46). G6PD deficiency (P = .000), higher Hb concentration at baseline (P = .000), higher parasitemia level at baseline (P = .02), and thalassemia (P = .027) influenced the initial decrease in Hb level, calculated as the nadir level minus the baseline level (range, -5.8-0 g/dL; mean, -1.88 g/dL). By day 14, the mean difference from the day 7 level (calculated as the day 14 level minus the day 7 level) was 0.03 g/dL (range, -0.25‒0.32 g/dL). Reticulocyte counts decreased from days 1 to 3, peaking on day 7 (in the G6PD normal group) and day 14 (in the G6PD deficient group); reticulocytemia at baseline (P = .001), G6PD deficiency (P = .000), and female sex (P = .034) correlated with higher counts. One symptomatic, G6PD-deficient, anemic male patient was transfused on day 4. CONCLUSIONS:The first PQ0.75 exposure was associated with the greatest decrease in Hb level and 1 blood transfusion, followed by clinically insignificant decreases in Hb levels. PQ0.75 requires monitoring during the week after treatment. Safer antirelapse regimens are needed in Southeast Asia. CLINICAL TRIALS REGISTRATION:ACTRN12613000003774.