Clinical efficacy of four schemes for vivax malaria treatment in children

Abstract

Objetivo: A cura da malaria vivax permanece dificultada por um fator determinante de recaídas: a duração do tratamento. Em Belém, a observação de que um grande número de pacientes com malaria vivax curava-se, a despeito do abandono do tratamento, levou à concretização deste estudo objetivando avaliar a eficácia de esquemas mais operacionais para malária em crianças. Métodos: Foi realizado ensaio clínico prospectivo e randomizado, em 200 crianças com malaria vivax, atendidas ambulatorialmente. Variáveis observadas: velocidade de negativação da parasitemia e respostas a quatro esquemas: a) cloroquina 10mg/kg-dose única (cloroquina DU) + primaquina 0,50/kg/dia por 7 dias; b) cloroquina DU + primaquina 0,25/kg/dia por 7 dias; c) cloroquina DU + primaquina 0,50/kg/dia por 5 dias; e d) cloroquina DU + primaquina 0,25/kg/dia por 5 dias. Para comparação das respostas obtidas foi utilizado o teste exato de Fisher. Resultados: Todas as 144 crianças que completaram o estudo apresentaram negativação da parasitemia até o quarto dia de tratamento. A comparação das respostas aos esquemas, mostrou resultados significativos entre os esquemas A e D (p= 0,022), e entre os esquemas C e D (p=0,005). Quanto à dose diária e ao tempo de duração, a comparação mostrou resultados significativos nos esquemas de doses duplicadas em relação aos de dose padrão (p=0,0042). Não ocorreram diferenças significativas quando se comparou o tempo de tratamento (p=0,6104). Conclusões: No grupo estudado, primaquina em doses duplicadas e tempo encurtado são mais eficazes que primaquina em dose padrão e tempo encurtado na cura radical de malaria vivax. A eficácia dos esquemas duplicados independe de duração do tratamento. Não é recomendada a utilização do esquema D.

Efficacy of Three Different Regimens of Primaquine for the Prevention of Relapses of Plasmodium vivax Malaria in the Amazon Basin of Peru

“…Also, regional studies already describe high relapse rates when one-half dose or less PQ is provided. 2,14,25,26,37 Finally, we found that an incomplete PQ regimen results in nearly 30% recurrence over 6 months, suggesting that studies with arms without radical cure drugs could induce preventable relapses.…”

“…report relapse rates of 20-30% 13,14,23,24 and even 36-57%. 25,26 Additionally, in our low-dose regimen, we observed that the actual dose received may be further associated with the risk of relapse.…”

“…Shorter 7-day PQ regimes had not been tested in Peru before the policy change, and 7-day or shorter regimes had shown mixed results in other South American countries. [13][14][15] Also, the greater susceptibility of P. vivax strains to PQ in the Americas compared with strains from southeast Asia and the Pacific 10 could offer additional room to benefit from shorter regimes with increased adherence. Therefore, we decided to compare the efficacy to prevent relapses of the WHO standard 14-day PQ regimen versus shortened regimes of 7 and 5 days that have been applied throughout the Americas.…”

Eficacia terapéutica de esquemas de Primaquina usados como alternativa al tratamiento estándar en la prevención de recaídas por Plasmodium vivax: Una revisión sistemática y meta-análisis

“…376 were duplicated and 251 articles were screened, out of which 229 were excluded. Twenty-three articles were fully read for review in the second phase, out of which 9 clinical trials met with the eligibility criteria; 7 studies for the qualitative systematic review of the primary objective 15 - 21 , out of these, 4 studies made a comparison with the standard regimen and were included in the meta-analysis 15 , 17 , 19 , 20 , the other 3 did not compare with the standard regimen 16 , 18 , 21 . Three studies for the secondary objective were identified 19 , 22 , 23 , one of which was also included in the primary objective; only one study made a comparison with the standard regimen 19, therefore, no studies for the quantitative synthesis of this objective were included ( Fig.…”

“…Table 1 shows the main characteristics of the studies. Three studies were conducted in Brazil 15 , 16 , 18 , two in Peru 17 , 20 , one in Colombia 21 , one in India 19 , one in Pakistan 22 , and one in Indonesia 23 . Only one study was conducted in a non-endemic region where reinfection during the follow-up was not possible 23 .…”