Practical Info In light of concern about the safety of the previously recommended dose of 0.75 mg/kg bw in individuals with G6PD deficiency, a WHO panel reviewed the safety of primaquine as a P. falciparum gametocytocide and concluded that a single dose of 0.25 mg/kg bw of primaquine base is unlikely to cause serious toxicity, even in people with G6PD deficiency [185]. Thus, where indicated a single dose of 0.25mg/kg bw of primaquine base should be given on the first day of treatment, in addition to an ACT, to all patients with parasitologically confirmed P. falciparum malaria except for pregnant women, infants < 6 months of age and women breastfeeding infants < 6 months of age, because there are insufficient data on the safety of its use in these groups. Dosing table based on the most widely currently available tablet strength (7.5mg base) Body weight (kg): Single dose of primaquine (mg base) 10 to < 25: 3.75 25 to < 50: 7.5 50 to 100: 15 Dosing of young children weighing < 10 kg is limited by the tablet sizes currently available. Please refer to the Policy brief on single-dose primaquine as a gametocytocide in Plasmodium falciparum malaria [186].

Remarks This recommendation excludes high-transmission settings, as symptomatic patients make up only a small proportion of the total population carrying gametocytes within a community, and primaquine is unlikely to affect transmission. A major concern of national policy-makers in using primaquine has been the small risk for haemolytic toxicity in G6PDdeficient people, especially where G6PD testing is not available. Life-threatening haemolysis is considered unlikely with the 0.25mg/kg bw dose and without G6PD testing [184].