Practical information on using primaquine and tafenoquine

Primaquine is essential for the treatment of malaria caused by Plasmodium vivax and Plasmodium ovale because it eradicates dormant parasites (hypnozoites) in the liver that can reactivate to cause relapsed malaria. Primaquine is also used to eliminate the transmissible stages of Plasmodium falciparum, preventing the transfer of parasites from human hosts to mosquitoes.

Exclude glucose-6-phosphate dehydrogenase (G6PD) deficiency before starting treatment with primaquine because patients who are deficient are at risk of developing severe haemolysis. Adverse effects of primaquine include gastrointestinal disturbance and methaemoglobinaemia.

Tafenoquine is registered in Australia for radical cure (prevention of relapse) of P. vivax malaria (in combination with chloroquine) and for malaria prophylaxis. While all currently available G6PD tests can be used to assess the safety of primaquine, a specific quantitative G6PD test is required to determine if G6PD activity is more than 70% for safe use of tafenoquine.