Artemether-Lumefantrine Dosing in Adults
For adults weighing >35 kg with uncomplicated malaria, artemether-lumefantrine is dosed as 4 tablets (80 mg artemether/480 mg lumefantrine total per dose) at 0 hours, 4 tablets at 8 hours on day 1, then 4 tablets twice daily on days 2 and 3, for a total of 24 tablets over 72 hours. 1
Standard Dosing Regimen
The specific timing schedule is critical for optimal efficacy:
- Day 1: 4 tablets at hour 0, then 4 tablets at hour 8 1, 2
- Day 2: 4 tablets at hour 36, then 4 tablets at hour 48 1
- Day 3: 4 tablets at hour 60, then 4 tablets at hour 72 1
Each tablet contains 20 mg artemether and 120 mg lumefantrine. 1
Critical Administration Requirements
Artemether-lumefantrine must be taken with a fatty meal or drink to ensure adequate absorption. 1, 2 This is not optional—failure to take the medication with fat can result in subtherapeutic lumefantrine levels and treatment failure. 2, 3, 4
The fatty meal requirement distinguishes artemether-lumefantrine from dihydroartemisinin-piperaquine, which must be taken in fasting conditions. 1
Weight-Based Considerations
For adults weighing >75 kg, some guidelines suggest considering higher doses or alternative regimens, though the standard 4-tablet dose is still recommended in most protocols. 1 The Swiss guidelines specifically recommend extending treatment to 5 days (adding 4 additional doses) in patients with higher body weight due to concerns about subtherapeutic lumefantrine concentrations. 1
Clinical Context and Efficacy
Artemether-lumefantrine is a first-line artemisinin-based combination therapy (ACT) for uncomplicated Plasmodium falciparum malaria, with cure rates of 96-100% in most settings. 2, 3, 4, 5 The six-dose regimen achieves significantly higher cure rates (96.9-99.1%) compared to the older four-dose regimen (83.3%). 5
The combination provides rapid parasite clearance through artemether's fast-acting antimalarial effect, while lumefantrine's longer half-life prevents recrudescence. 1
Important Safety Considerations
Both artemether and lumefantrine can cause QTc interval prolongation. 1, 2 Avoid use in patients at risk of QTc prolongation or those taking medications that prolong the QTc interval. 1, 3
Monitor for post-artemisinin delayed hemolysis (PADH), particularly on days 7,14,21, and 28 after treatment. 1, 3 One prospective study reported PADH in 37.4% of patients using strict diagnostic criteria, though this is typically mild and self-limited. 1
Common adverse effects include headache, vertigo, and digestive disorders, which are generally mild and self-limited. 1
Special Populations
Artemether-lumefantrine can be used in all trimesters of pregnancy as endorsed by WHO and CDC guidelines, making it one of the few antimalarials safe throughout pregnancy. 1, 2, 3
The regimen has been validated in HIV-infected patients, including those on antiretroviral therapy, though drug interactions with protease inhibitors can significantly increase lumefantrine exposure. 6
Common Pitfalls to Avoid
Failing to ensure adequate fat intake is the most common cause of treatment failure with artemether-lumefantrine. 2, 3, 4 Patients should consume at least 1.2 grams of fat with each dose.
Using artemether-lumefantrine for malaria acquired in Southeast Asia (particularly the Greater Mekong subregion) where artemisinin resistance is established requires careful consideration and potentially alternative regimens. 1
Incomplete dosing regimen due to the complex six-dose schedule over 72 hours can lead to treatment failure. 1 Clear patient education and potentially supervised therapy for the first doses improves adherence.