Reversal of chloroquine resistance of Plasmodium vivax in Aotus monkeys

Chloroquine resistant (CQR) vivax malaria has emerged as a threat to the malaria elimination agenda. The objective of this study was to assess if a combination of chloroquine (CQ) and prochlorperazine was able to reverse CQ resistance of the Plasmodium vivax AMRU-1 strain from Papua New Guinea in infected Aotus monkeys. For this purpose, in two independent experimental drug efficacy trials, a total of eighteen Aotus monkeys infected with blood obtained from donor animals, were randomly assigned into treatment and control groups and administered CQ at 10 mg/kg or prochlorperazine at 20 mg/kg orally for five consecutive days alone or in combination. Reversal of CQR was achieved in animals that received the drug combination, whereas neither drug alone produced cures. This same drug combination reverses CQR in P. falciparum and could be an alternative for treatment in humans with chloroquine resistance P. vivax infections.