title: High-dose primaquine regimens against relapse of Plasmodium vivax malaria.
abstract: Plasmodium vivax causes debilitating but usually non-lethal malaria in most of Asia and South America. Prevention of relapse after otherwise effective therapy for the acute attack requires a standard daily dose of primaquine administered over 14 days. This regimen has < 90% efficacy in Thailand, and is widely regarded as ineffective because of poor compliance over the relatively long duration of dosing. We evaluated the efficacy, safety, and tolerability of alternative primaquine dosing regimens combined with artesunate among 399 Thai patients with acute, symptomatic P. vivax malaria. Patients were randomly assigned to one of six treatment groups: all patients received artesunate, 100 mg once a day for 5 days. Groups 1-5 then received primaquine, 30 mg a day for 5, 7, 9, 11, and 14 days, respectively. Group 6 received primaquine, 30 mg twice a day for 7 days. The 28-day cure rates were 85%, 89%, 94%, 100%, and 96%, respectively. Treatment of P. vivax malaria with artesunate for 5 days followed by high-dose primaquine, 30 mg twice a day for 7 days, was highly effective, well-tolerated, and equivalent or superior to the standard regimen of primaquine therapy.
authors.affiliation: Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. tmsks@mahidol.ac.th
authors.forename: Srivicha
authors.initials: S
authors.lastname: Krudsood
authors.forename: Noppadon
authors.initials: N
authors.lastname: Tangpukdee
authors.forename: Polrat
authors.initials: P
authors.lastname: Wilairatana
authors.forename: Nantaporn
authors.initials: N
authors.lastname: Phophak
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Baird
authors.forename: Gary M
authors.initials: GM
authors.lastname: Brittenham
authors.forename: Sornchai
authors.initials: S
authors.lastname: Looareesuwan
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016780:Malaria, Vivax / Q000188:drug therapy* / Q000517:prevention & control*; D008297:Male; D011319:Primaquine / Q000008:administration & dosage / Q000627:therapeutic use*; D012008:Recurrence; D013163:Splenomegaly / Q000453:epidemiology / Q000469:parasitology; D013785:Thailand; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D011319:Primaquine