title: Short report: a consideration of primaquine dose adjustment for radical cure of Plasmodium vivax malaria.
abstract: Relapse of Plasmodium vivax malaria following standard primaquine dosing has been reported from many areas, and more recently from sub-Saharan Africa. In this report we describe eight episodes (in five patients) of treatment failure in non-immune Israeli travelers returning from Ethiopia. Retrospective calculation of the primaquine dose per kilogram of body weight for 23 treatment courses showed a lower total dose per kilogram in heavier patients. The mean calculated dose (95% CI) in the eight failed treatments was 2.5 +/- 0.3 mg/kg compared with 4.4 +/- 0.5 mg/kg in the 15 successful treatment courses. Weight-adjusted dosing regimens may prevent inadvertent subtherapeutic drug failure, and thus apparent primaquine failure. In these cases, no relapses were observed in those who received > 3.5 mg/kg. Consideration should be given to adjusting the dose of primaquine according to body weight. For those infected by strains from Ethiopia a dose > 3.5 mg/kg is preferable.
authors.affiliation: Center for Geographical Medicine and Department of Medicine C, Chaim Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Schwartz
authors.forename: G
authors.initials: G
authors.lastname: Regev-Yochay
authors.forename: D
authors.initials: D
authors.lastname: Kurnik
mesh_terms: D000962:Antimalarials / Q000008:administration & dosage*; D001835:Body Weight; D004351:Drug Resistance; D006801:Humans; D016780:Malaria, Vivax / Q000188:drug therapy*; D011319:Primaquine / Q000008:administration & dosage*; D012189:Retrospective Studies
chemical_list: D000962:Antimalarials; D011319:Primaquine