From the Guidelines
The current treatment guidelines for Plasmodium vivax malaria recommend a combination of blood schizonticide therapy plus anti-relapse therapy, with chloroquine (total dose of 25 mg base/kg divided over 3 days) for the acute blood stage infection, followed by primaquine (0.25-0.5 mg/kg daily for 14 days) to prevent relapses by eliminating liver hypnozoites, as stated in the latest study from 2024 1. The treatment approach for P. vivax malaria involves:
- Blood schizonticide therapy to eliminate the acute blood stage infection
- Anti-relapse therapy to prevent relapses by eliminating liver hypnozoites The first-line treatment consists of:
- Chloroquine (total dose of 25 mg base/kg divided over 3 days) for the acute blood stage infection
- Primaquine (0.25-0.5 mg/kg daily for 14 days) to prevent relapses by eliminating liver hypnozoites In areas with chloroquine-resistant P. vivax, artemisinin-based combination therapies (ACTs) such as artemether-lumefantrine or dihydroartemisinin-piperaquine are recommended instead of chloroquine, as supported by a meta-analysis based on randomized controlled studies conducted in endemic areas 1. Before starting primaquine, patients should be tested for glucose-6-phosphate dehydrogenase (G6PD) deficiency, as primaquine can cause hemolysis in G6PD-deficient individuals, highlighting the importance of G6PD testing prior to treatment 1. For those with G6PD deficiency, weekly primaquine (0.75 mg/kg) for 8 weeks or close monitoring during therapy may be considered. Pregnant women should receive chloroquine only, with primaquine deferred until after delivery. Treatment should begin immediately upon diagnosis, as P. vivax can cause severe disease despite its reputation as "benign" malaria. The dual-therapy approach is essential because chloroquine or ACTs alone eliminate only blood-stage parasites, while primaquine is needed to prevent relapses by clearing liver hypnozoites that can cause multiple recurrences for months to years after the initial infection.
From the FDA Drug Label
Of the 23 patients in Thailand infected with P vivax and treated with atovaquone/proguanil hydrochloride 1,000 mg/400 mg daily for 3 days, parasitemia cleared in 21 (91. 3%) at 7 days. Parasite relapse occurred commonly when P. vivax malaria was treated with atovaquone and proguanil hydrochloride alone. Chloroquine does not treat the hypnozoite liver stage forms of Plasmodium and will therefore not prevent relapses of malaria due to P. vivax or P. ovale. Additional treatment with an anti-malarial agent active against these forms, such as an 8-aminoquinoline, is required for the treatment of infections with P. vivax and P. ovale
The latest treatment guidelines for Plasmodium vivax malaria are not explicitly stated in the provided drug labels. However, it can be inferred that:
- Atovaquone/proguanil hydrochloride may be effective in clearing parasitemia in the short term, but relapse is common when used alone for P. vivax malaria 2.
- Chloroquine is not effective in preventing relapses of P. vivax malaria due to its inability to treat the hypnozoite liver stage forms of the parasite, and additional treatment with an 8-aminoquinoline is required 3. It is essential to consult the latest clinical guidelines and expert recommendations for the treatment of P. vivax malaria, as the provided information is limited and may not reflect the current standard of care.
From the Research
Latest Plasmodium Vivax Malaria Treatment Guidelines
The latest treatment guidelines for Plasmodium vivax malaria involve a combination of therapies to target both the blood stages of the parasite and the prevention of subsequent relapses.
- Chloroquine and Primaquine: These have been the traditional companion therapies of choice for the treatment of vivax malaria since the 1950s 4. However, confirmed resistance to chloroquine occurs in much of the vivax endemic world, necessitating the investigation of alternative blood schizontocidal companions in radical cure.
- Alternative Regimens: Studies have explored alternative primaquine regimens for radical cure of P. vivax malaria, including different dosing schedules and combinations with other drugs 5, 6, 7, 8.
- Primaquine Dosing Schedules: Research has compared the efficacy and safety of different primaquine dosing schedules, including 0.5 mg/kg/day for 7 days, 0.5 mg/kg/day for 14 days, and 0.75 mg/kg/week for 8 weeks 5.
- Combination Therapies: Combination therapies, such as arterolane maleate and piperaquine phosphate, have shown efficacy and safety in treating uncomplicated vivax malaria 7.
- Safety and Efficacy: The safety and efficacy of primaquine when administered with other therapies, particularly in patients with glucose-6-phosphate dehydrogenase deficiency, are crucial considerations in the treatment of vivax malaria 5, 4, 8.
Treatment Options
Treatment options for Plasmodium vivax malaria include:
- Chloroquine plus primaquine 6, 4
- Arterolane maleate and piperaquine phosphate 7
- Quinine plus primaquine 8
- Dihydroartemisinin-piperaquine plus primaquine 8
Considerations
Considerations in the treatment of Plasmodium vivax malaria include: