Most Common Treatments for Malaria
For uncomplicated P. falciparum malaria, artemisinin-based combination therapies (ACTs)—specifically artemether-lumefantrine or dihydroartemisinin-piperaquine—are the first-line treatments, while intravenous artesunate is the definitive treatment for severe malaria. 1
Treatment Algorithm by Malaria Type and Severity
Uncomplicated P. falciparum Malaria
First-line treatment consists of oral ACTs 1:
Artemether-lumefantrine (AL): For patients >35 kg, give 4 tablets at hours 0 and 8 on day 1, then 4 tablets twice daily on days 2-3 (total 24 tablets over 72 hours). Must be taken with fatty food or drink. Can be used in all trimesters of pregnancy 1
Dihydroartemisinin-piperaquine: For patients 36-75 kg, give 3 tablets daily for 3 days; >75 kg give 4 tablets daily for 3 days. Must be taken fasting. Avoid in patients with QTc prolongation risk 1
Second-line alternatives when ACTs are contraindicated or for patients from Southeast Asia (Greater Mekong sub-region) with high ACT resistance 1:
- Atovaquone-proguanil
- Quinine sulfate plus doxycycline, clindamycin, or mefloquine
Uncomplicated Non-falciparum Malaria (P. vivax, P. ovale, P. malariae)
Chloroquine remains the drug of choice for chloroquine-sensitive regions, with a total dose of 25 mg base/kg over 3 days 1.
For chloroquine-resistant P. vivax (Papua New Guinea, Indonesia, Sabah where resistance exceeds 10%), use ACTs 1.
Critical addition for P. vivax and P. ovale: Following blood schizontocidal treatment, patients require primaquine or tafenoquine to prevent relapse from liver hypnozoites. Must test for G6PD deficiency before administering—both drugs are contraindicated in G6PD deficiency and pregnancy 1.
Severe Malaria
Intravenous artesunate is the first-line treatment for severe malaria 2, 3. Severe malaria is defined by WHO criteria including unarousable coma, multiple convulsions, shock, pulmonary edema, acute respiratory distress syndrome, oliguria (<400 mL/24 hours), severe anemia (hemoglobin <7 g/dL), acidosis, hypoglycemia, hyperparasitemia (>5% for non-immune, >10% for semi-immune), or serum creatinine >3 mg/dL 1.
Important Clinical Considerations
Post-Artemisinin Delayed Hemolysis (PADH)
This is the most serious adverse event with ACTs. While initially described with IV artesunate, it occurs in 1.9% of patients treated with oral artemether-lumefantrine 1. A recent prospective study using stricter definitions found 37.4% prevalence on day 14 after treatment 1. Monitor hemoglobin and haptoglobin levels post-treatment.
Drug Resistance Patterns
- P. falciparum has developed chloroquine resistance in most regions worldwide, including Africa 2
- Established ACT resistance exists in the Greater Mekong sub-region 1
- Only three non-endemic countries adjust treatment recommendations based on expected artemisinin resistance, despite this being a critical consideration 4
Common Pitfalls to Avoid
- Body weight affects lumefantrine therapeutic concentrations—Swiss guidelines recommend extending AL treatment from 3 to 5 days in some patients 1
- QTc prolongation risk with both dihydroartemisinin-piperaquine and artemether-lumefantrine—avoid in patients with baseline QTc issues or medications that prolong QTc 1
- Forgetting primaquine for P. vivax/P. ovale—relapse occurs in 9.3% of P. vivax cases without primaquine, with an 80% risk reduction when prescribed 1
- Not testing for G6PD deficiency before prescribing 8-aminoquinolines leads to potentially severe hemolysis
Geographic Considerations
ACTs are first-line in most guidelines except Canadian ones where they remain unavailable 1. For Haiti and other known chloroquine-sensitive regions, chloroquine remains an alternative for P. falciparum 2.