Primaquine for preventing relapses in people with Plasmodium vivax malaria

Primaquine (15 mg/kg/day for 14 days) plus chloroquine is more effective than chloroquine alone or primaquine (15 mg/kg for 5 days) plus chloroquine in preventing relapses of vivax malaria. Primaquine (five days) plus chloroquine appears no better than chloroquine. Countries should follow the WHO's recommendation for 14-day primaquine plus chloroquine regimen. Alternative regimens need to be evaluated in randomized controlled trials, which should also consider variations in regional P. vivax strains and the possibility of primaquine resistance, reinfection, and adherence in those who relapse.