Srivicha KrudsoodNoppadon TangpukdeePolrat WilairatanaNantaporn PhophakJ. Kevin BairdGary M. BrittenhamSornchai LooareesuwanMahidol UniversityThe Asia FoundationColumbia University, College of Physicians and Surgeons2018-07-122018-07-122008-05-01American Journal of Tropical Medicine and Hygiene. Vol.78, No.5 (2008), 736-740000296372-s2.0-45349087314https://repository.li.mahidol.ac.th/handle/123456789/19333Plasmodium 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. Copyright © 2008 by The American Society of Tropical Medicine and Hygiene.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS