[Clinical efficacy of four schemes for vivax malaria treatment in children]

OBJECTIVES: In the treatment of vivax malaria, an important factor affecting the occurrence of relapse is the duration of treatment. In Belém, a number of patients with vivax malaria were found to be cured despite failure to complete the standard course of treatment. In Belém, a number of patients with vivax malaria were found to be cured despite failure to complete the standard course of treatment. This observation suggested the present study, investigating more practicable courses of treatment for children with vivax malaria.METHODS: A randomized prospective clinical trial was conducted in 200 outpatient children with vivax malaria. Parasite clearance time and response to four therapeutic schedules were investigated: a) chloroquine*, 10 mg/kg in a single dose (chloroquine SD) + primaquine, 0.50 mg/kg/dose for 7 days; b) chloroquine SD + primaquine, 0.25 mg/kg/dose for 7 days; c) chloroquine SD + primaquine, 0.50 mg/kg/dose for 5 days; d) chloroquine SD + primaquine, 0.25 mg/kg/dose for 5 days. Fisherśs Exact test was used to compare the responses to the schedules.RESULTS: All 144 children who completed the study had clearance of asexual parasitemia by the fourth day of treatment. Significant differences were observed between schedules A/D (p= 0.022) and C/D (p= 0.005). A doubled dose of primaquine (schedules A and C) proved to be significantly more effective (p=0.0042) than the standard dose (B and D). However, duration of treatment had no significant effect (p = 0.6104).CONCLUSIONS: In this study, complete cure of vivax malaria was better achieved with a doubled dose of primaquine than with standard doses. Effectiveness of the doubled dose was independent of the duration of treatment. Treatment schedule D is not recommended.