Guidance for Using Tafenoquine for Prevention and Antirelapse Therapy for Malaria — United States, 2019

Julia C. Haston, MD; Jimee Hwang, MD; Kathrine R. Tan, MD

Disclosures

Morbidity and Mortality Weekly Report. 2019;68(42):1062-1068. 

In This Article

Background

In 2016, a total of 2,078 imported malaria cases were reported in the United States; of the 1,853 (89.2%) cases with known species, 76.6% were caused by P. falciparum, 18.8% by P. vivax or P. ovale, and 4.5% by P. malariae or mixed infections.[5] Plasmodium first develops in the liver before emerging up to 1 month later to infect red blood cells. Almost all antimalarials target only the blood stage of the parasite. Therefore, most chemoprophylaxis drugs are taken for 1 month after leaving the malaria area to allow the parasite to reach the targeted blood stage. However, P. vivax and P. ovale develop hypnozoites, a dormant stage of the parasite in the liver that can emerge months later to cause disease relapses. Treatment of these species requires antirelapse therapy (also known as radical treatment or radical cure). For travelers with intense or prolonged exposure to relapsing species of malaria, presumptive antirelapse therapy (PART) is recommended to kill hypnozoites.[6] Until recently, only primaquine was used for this indication.

Tafenoquine, an 8-aminoquinoline drug related to primaquine, is only the second drug of its class to receive FDA approval. Tafenoquine kills both the liver and blood stages of the parasite, broadening its applicability for chemoprophylaxis to all species of malaria. FDA approved tafenoquine for prophylaxis of malaria in adults aged ≥18 years (Arakoda, 100 mg tablets) in August 2018 and antirelapse therapy of P. vivax malaria in persons aged ≥16 years (Krintafel, 150 mg tablets) in July 2018.[7,8] Like primaquine, tafenoquine can cause severe hemolysis in persons with glucose-6-phosphate dehydrogenase (G6PD) deficiency and quantitative G6PD testing is required before prescribing. Tafenoquine use is contraindicated in persons with G6PD deficiency.[9]

This report summarizes the published efficacy and safety evidence for the recommended doses for both indications and provides guidance for the use of tafenoquine in the United States. A more comprehensive review of the literature on tafenoquine along with the biologic rationale for its use has been published elsewhere.[10]

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