Association of subtherapeutic dosages of a standard drug regimen with failures in preventing relapses of vivax malaria

Citation
Ec. Duarte et al., Association of subtherapeutic dosages of a standard drug regimen with failures in preventing relapses of vivax malaria, AM J TROP M, 65(5), 2001, pp. 471-476
Citations number
15
Categorie Soggetti
Envirnomentale Medicine & Public Health","Medical Research General Topics
Journal title
AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE
ISSN journal
00029637 → ACNP
Volume
65
Issue
5
Year of publication
2001
Pages
471 - 476
Database
ISI
SICI code
0002-9637(200111)65:5<471:AOSDOA>2.0.ZU;2-3
Abstract
This study evaluated the cure rate of the standard recommended regimen for Plasmodium vivax malaria in Brazil and assessed risk factors for failures. Fifty patients with vivax malaria given supervised medical treatment (stand ard dose of chloroquine: total dose = 1.5 g over a three-day period plus pr imaquine: total dose = 210 mg over a 14-day period) were followed for six m onths in a non-endemic area. Cox's regression was used to identify predicto rs of relapses. Among the 289 patient-months of follow-up, seven relapses w ere identified (2.4 relapses per 100 person-months) between 33 and 137 days after treatment initiation. Risk factors for relapses (P less than or equa l to 0.05) were female sex, higher parasitemia at baseline, shorter number of days with symptoms prior to baseline, and lower mg/kg dose of primaquine . Relapses following supervised vivax treatment is in principle a necessary , but not sufficient, component of in vivo parasite resistance. Results ind icate that other factors, principally sub-therapeutic primaquine doses, may explain the occurrence of vivax treatment failures.