The optimal treatment for vivax malaria acquired in New Guinea is unknown. Mefloquine and halofantrine have been shown to be efficacious in small clinical trials, but each is limited by safety issues associated with therapeutic doses. Expert advice from an infectious or tropical disease specialist should be sought for the management of these cases. None of the currently recommended chemosuppressive regimens will prevent relapses due to these two species of malaria. Primaquine is not recommended for routine use to prevent relapsing malaria in asymptomatic returning travellers.
Primaquine use is contraindicated in pregnancy.
Primaquine is generally well tolerated but may cause nausea and abdominal pain which may be diminished by taking the drug with food. These individuals, in particular, should have their G6PD level measured before primaquine therapy is initiated. Primaquine is contraindicated in patients with severe deficiency. Patients should be advised to stop their medication and report to a physician immediately if jaundice or abnormally dark or brown urine is noted. Recently, primaquine treatment failure has been reported from Thailand and Somalia.