title: Efficacy of primaquine regimens for primaquine-resistant Plasmodium vivax malaria in Thailand.
abstract: To define the current efficacy of Fansidar (F. Hoffmann-La Roche Ltd., Basel Switzerland) (pyrimethamine and sulfadoxine), primaquine in a high dose, and artesunate for treating acute Plasmodium vivax malaria, we conducted a comparative clinical trial of these 3 drugs in an open-label study. Patients (15-65 years old) were assigned to 1 of 4 treatments regimens in a serial order. Ninety percent of the patients were infected at Thailand-Myanmar border. Patients in group I (n = 23) received Fansidar (3 tablets, 75 mg of pyrimethamine and 1,500 mg of sulfadoxine, a single dose on the first day), group II (n = 23) received Fansidar (3 tablets, 75 mg of pyrimethamine and 1,500 mg of sulfadoxine, a single dose on the first day) and then received primaquine (30 mg a day for 14 days), group III (n = 23) received primaquine (30 mg a day for 14 days), and group IV (n = 23) received artesunate (200 mg once a day for 3 days) and then primaquine (30 mg a day for 14 days). Cure rates on day 28 of follow-up were 40%, 100%, 100%, and 100% in groups I, II, II, and IV, respectively. There were 4 and 5 patients in group I showing post-treatment reappearance of parasitemia at < or = 16 days and between 17 and 28 days, respectively. Patients in the other 3 groups showed negative parasitemias within 7 days after treatment. Artesunate plus primaquine (group IV) cleared parasitemia faster than the other 3 regimens. There is a high proportion of ineffectiveness of Fansidar for treatment of P. vivax malaria and it should be no longer used for treatment of P. vivax malaria acquired at the Thailand-Myanmar border. A high dose of primaquine is safe and effective in the treatment of P. vivax malaria during the 28-day follow-up period.
authors.affiliation: Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: P
authors.initials: P
authors.lastname: Wilairatana
authors.forename: U
authors.initials: U
authors.lastname: Silachamroon
authors.forename: S
authors.initials: S
authors.lastname: Krudsood
authors.forename: P
authors.initials: P
authors.lastname: Singhasivanon
authors.forename: S
authors.initials: S
authors.lastname: Treeprasertsuk
authors.forename: V
authors.initials: V
authors.lastname: Bussaratid
authors.forename: W
authors.initials: W
authors.lastname: Phumratanaprapin
authors.forename: S
authors.initials: S
authors.lastname: Srivilirit
authors.forename: S
authors.initials: S
authors.lastname: Looareesuwan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use*; D037621:Artemisinins; D000077332:Artesunate; D004338:Drug Combinations; D004351:Drug Resistance; D005260:Female; D006801:Humans; D016780:Malaria, Vivax / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D018512:Parasitemia / Q000188:drug therapy; D010966:Plasmodium vivax / Q000187:drug effects* / Q000302:isolation & purification; D011319:Primaquine / Q000494:pharmacology* / Q000627:therapeutic use; D011739:Pyrimethamine / Q000627:therapeutic use*; D012717:Sesquiterpenes / Q000627:therapeutic use*; D013413:Sulfadoxine / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D004338:Drug Combinations; D012717:Sesquiterpenes; C001205:fanasil, pyrimethamine drug combination; D000077332:Artesunate; D013413:Sulfadoxine; D011319:Primaquine; D011739:Pyrimethamine