Additional considerations for P. vivax and P. ovale

P. vivax and P. ovale can exist as dormant parasites (hypnozoites) in the liver that can reactivate to cause a relapse of malaria. The treatment regimens for uncomplicated malaria (see above) do not eliminate hypnozoites, so concurrent treatment with primaquine (for P. vivax or P. ovale) or tafenoquine (for P. vivax) is required to eliminate dormant liver parasites.

Primaquine and tafenoquine¹ can cause severe haemolysis in patients who are glucose-6-phosphate dehydrogenase (G6PD) deficient—if the patient is G6PD deficient, seek expert advice.

For P. vivax infection, once G6PD deficiency has been excluded, add to the standard treatment regimen for uncomplicated malaria:

primaquine 30 mg (child over 6 months: 0.5 mg/kg up to 30 mg) orally, daily, or if nausea occurs 15 mg (child over 6 months: 0.25 mg/kg up to 15 mg) orally, 12-hourly. Treat for 14 days or, in adults more than 70 kg, until a total cumulative dose of 6 mg/kg is reached² ³. malaria, Plasmodium vivax primaquine

For P. ovale infection, once G6PD deficiency has been excluded, add to the standard treatment regimen for uncomplicated malaria:

primaquine 15 mg (child over 6 months: 0.25 mg/kg up to 15 mg) orally, daily for 14 days³. malaria, Plasmodium ovale primaquine

If a relapse of malaria occurs despite treatment with primaquine or tafenoquine, seek expert advice.

¹ Tafenoquine is registered in Australia for radical cure (prevention of relapse) of P. vivax malaria (in combination with chloroquine for treatment of the acute infection). While all currently available G6PD tests can be used to assess the safety of the daily primaquine regimen, determining if G6PD activity is greater than 70% for safe use of tafenoquine requires a specific quantitative G6PD test. If considering the use of tafenoquine for radical cure of P. vivax malaria, seek expert advice on G6PD testing and tafenoquine dosing.Return

² Evidence suggests that relapses of malaria caused by P. vivax are more common if primaquine is not used, or if the total cumulative dose of primaquine is less than 6 mg/kg, especially when the infection has been acquired in Indonesia, Timor-Leste or Pacific Island countries. Adults who weigh more than 70 kg require treatment for 15 days or longer to reach a cumulative dose of 6 mg/kg. Return

³ Do not use primaquine in pregnant women, infants younger than 6 months and breastfeeding women with infants under 6 months—seek expert advice. Return