1. Clinical Overview
Artemether-Lumefantrine is a fixed-dose combination antimalarial medication, classified as an Artemisinin-based Combination Therapy (ACT). It is the first-line treatment for uncomplicated Plasmodium falciparum malaria in India and globally, as per WHO and National Center for Vector Borne Diseases Control (NCVBDC) guidelines. Artemether provides rapid reduction of parasite biomass, while lumefantrine eliminates residual parasites, preventing recrudescence and reducing the potential for drug resistance.
| Onset | Duration | Bioavailability |
|---|---|---|
| Artemether: 2-3 hours; Lumefantrine: Variable, but synergistic action starts within hours. | Artemether: 6-11 hours (short-acting). Lumefantrine: 4-6 days (long-acting). | Artemether: ~70% (highly variable, increased with fatty food). Lumefantrine: ~10% when fasted, increases significantly (up to 16-fold) with a fatty meal. |
2. Mechanism of Action
The combination exerts a rapid, synergistic schizonticidal effect against the asexual erythrocytic stages of Plasmodium falciparum. Artemether acts quickly to reduce the parasite load by >10,000-fold within 48 hours ('parasite clearance'). Lumefantrine, which has a longer half-life, then eliminates the remaining parasites, providing a 'post-artemisinin' protective effect to prevent recrudescence.
3. Indications & Uses
- Treatment of uncomplicated Plasmodium falciparum malaria
- First-line therapy for malaria in areas with chloroquine resistance (includes most of India)
4. Dosage & Administration
Adult Dosage: A 3-day, six-dose regimen. Each dose is 4 tablets of the 20mg/120mg strength OR 2 tablets of the 40mg/240mg strength. Initial dose, followed by second dose at 8 hours, then twice daily (morning and evening) for the next two days (total of 6 doses over 60 hours).
Administration: MUST be taken with food, preferably a fatty meal (e.g., milk, curd, full-fat dairy) or at least a glass of milk. Improves lumefantrine absorption dramatically. If vomiting occurs within 1 hour of dosing, a repeat dose should be taken. Tablets can be crushed for children or those unable to swallow.
5. Side Effects
Common side effects may include:
- Headache
- Dizziness
- Anorexia
- Nausea
- Abdominal pain
- Diarrhea
- Cough
- Palpitations
- Prolonged QT interval on ECG (asymptomatic)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Ketoconazole, Itraconazole, Voriconazole | Strong CYP3A4 inhibitors; increase plasma concentrations of both artemether and lumefantrine, increasing risk of QTc prolongation and adverse effects. | Major |
| Rifampicin, Carbamazepine, Phenytoin, St. John's Wort | Strong CYP3A4 inducers; significantly reduce plasma concentrations of both drugs, leading to treatment failure. | Major |
| Antiarrhythmics (Amiodarone, Quinidine, Sotalol), Antipsychotics (Haloperidol, Pimozide), Macrolides (Erythromycin, Clarithromycin) | Concomitant use is contraindicated due to additive risk of QTc prolongation and life-threatening arrhythmias. | Contraindicated |
| Mefloquine, Halofantrine | Increased risk of QTc prolongation and potentially fatal cardiotoxicity. A minimum gap of 12 hours after last lumefantrine dose is advised if mefloquine is needed for prophylaxis. | Major |
| Hormonal Contraceptives | Artemether may reduce efficacy due to enzyme induction; advise use of non-hormonal barrier methods during and for 1 month after treatment. | Moderate |
7. Patient Counselling
- DO take with food/milk. This is not optional.
- DO complete the full 3-day, 6-dose course even if you feel better after 1-2 days.
- DO inform your doctor if you have any heart problems or are on any other medications.
- DO NOT take with grapefruit juice.
- DO NOT take mefloquine for prophylaxis within 12 hours of the last dose.
8. Toxicology & Storage
Overdose: Nausea, vomiting, dizziness, syncope, QTc interval prolongation leading to ventricular arrhythmias (Torsades de Pointes), headache, ataxia. No specific clinical picture established due to rarity.
Storage: Store below 30°C. Protect from moisture. Keep in the original blister pack until use. Keep out of reach of children.