London: A new study has claimed that lower doses of the antimalarial drug, primaquine, are as effective as higher doses in reducing malaria transmission.
Primaquine is one of the few antimalarial drugs that targets the transmission stages of the malaria parasite, the gametocytes, and is therefore considered to be an important tool for malaria elimination.
The study, carried out in Jinja, Uganda, treated G6PD-normal children with a conventional anti-malarial drug either on its own or with one of three different doses of primaquine. The subsequent carriage of malaria gametocytes was monitored for two weeks and safety outcomes were monitored for four weeks.
Results showed that a dose of 0.4 mg per kg, approximately half of the previously recommended dose (0.75 mg per kg), was as effective at reducing the transmission potential of individuals with malaria.
These results establish that low dose primaquine is still effective and safe in a G6PD-normal population, and paves the way for using low-dose primaquine as a component of strategies to reduce malaria transmission and to stop the spread of drug-resistant malaria parasites.
Lead author Dr Chi Eziefula, Wellcome Trust clinical research fellow, said: "Until now, the use of primaquine was limited because of safety concerns, but lower doses had never been tested formally. These findings, that efficacy is retained at a lower dose, imply that primaquine could play an important role in malaria elimination programmes."
The study was published in Lancet Infectious Diseases.