BACKGROUND:primaquine (PQ) is the only drug available in the market to prevent Plasmodiumvivax malaria recurrence, but several aspects are still unknown.
OBJECTIVE: To compare PQ regimens to prevent recurrence of vivax malaria.
METHODS: systematic review and meta-analysis of data.
RESULTS: 1. According to descriptive studies, is PQ effective in preventingrecurrence of vivax malaria? Yes. The comparison of studies that did not usePQ to others that did, using any regimen, showed that if PQ is not used, recurrenceis highly likely. 2. Are equal daily doses effective (mg/kg) but total dosesdifferent? The total dose of 75 mg is equally or more effective than 210 mg.3. Does the efficacy depend on where the infection happens? Yes. There is variationby country and region. 4. Does the recurrence rate depend on the post-treatmenttime follow-up? The answer is not uniform everywhere.
CONCLUSIONS: Although not 100%, PQ is effective in preventing recurrence.Total doses of 210 and 75 mg are equally effective, but 75 mg alone has beenevaluated in India, where P. vivax seems to respond better to PQ thanelsewhere. The effect of place in the proportion of recurrences seems evident,even using the same total dose. The role of follow-up time is not clear. Althoughthe standard regimen has an average effectiveness of 90% or more, alternativeregimens should be assessed.
