Artemether

# Artemether ## Overview - **Classification**: Antimalarial, Artemisinin derivative. - **Mechanism**: Metabolized to dihydroartemisinin. Produces reactive oxygen species and inhibits parasite growth by alkylating proteins and inhibiting parasite-encoded PfATP6. ## Primary Indications 1. **Uncomplicated *Plasmodium falciparum* Malaria**: Treatment of acute, uncomplicated infections. * *Note*: Artemether is almost exclusively available and prescribed as a fixed-dose combination with lumefantrine (Artemether/Lumefantrine). Dosing refers to the artemether component within this combination. ## Adult Dosing ### Standard Dosing **Uncomplicated *P. falciparum* Malaria (Artemether/Lumefantrine 20 mg/120 mg)** - **Dose**: **80 mg artemether** (4 tablets of 20 mg/120 mg) per dose. - **Frequency**: Total of 6 doses over 3 days. Administer initial dose, then repeat at 8 hours, then twice daily (morning & evening) for the next 2 days. - **Route**: Oral. - **Duration**: 3 days (total 6 doses). - **Special Considerations**: Administer with food or milk to enhance absorption. If vomiting occurs within 1 hour of a dose, repeat the dose. ### Dose Adjustments - **Renal Impairment**: No dosage adjustment required. - **Hepatic Impairment**: Use with caution in severe impairment; no specific dose adjustments established. - **Elderly Patients**: No specific dose adjustments needed, but monitor carefully for adverse effects due to potential comorbidities. ## Pediatric Dosing * *Note*: Dosing is based on body weight for Artemether/Lumefantrine 20 mg/120 mg tablets. Administer with food. Tablets can be crushed and mixed with a small amount of water for young children. ### Neonates (0-28 days) - **Dose**: Not recommended for infants weighing less than **5 kg** due to lack of clinical data. - **Special Notes**: Consider alternative treatments or specialist consultation for malaria in this age group. ### Infants (1-12 months, typically 5 to <15 kg) **Uncomplicated *P. falciparum* Malaria (Artemether/Lumefantrine 20 mg/120 mg)** - **Dose**: **20 mg artemether** (1 tablet of 20 mg/120 mg) per dose. - **Frequency**: Total of 6 doses over 3 days (initial, then 8 hours later, then twice daily for 2 days). - **Maximum**: Not to exceed adult dosing per dose. - **Special Notes**: Crucial to administer with food/milk. Ensure full course is completed. ### Children (1-12 years, typically 5 to <35 kg) **Uncomplicated *P. falciparum* Malaria (Artemether/Lumefantrine 20 mg/120 mg)** - **5 to <15 kg**: **20 mg artemether** (1 tablet) per dose. - **15 to <25 kg**: **40 mg artemether** (2 tablets) per dose. - **25 to <35 kg**: **60 mg artemether** (3 tablets) per dose. - **Frequency**: Total of 6 doses over 3 days (initial, then 8 hours later, then twice daily for 2 days). - **Maximum**: Not to exceed adult dosing per dose (**80 mg artemether**). - **Special Notes**: Emphasize administration with fatty food. ### Adolescents (13-18 years, typically ≥35 kg) **Uncomplicated *P. falciparum* Malaria (Artemether/Lumefantrine 20 mg/120 mg)** - **Dose**: **80 mg artemether** (4 tablets of 20 mg/120 mg) per dose. - **Frequency**: Total of 6 doses over 3 days (initial, then 8 hours later, then twice daily for 2 days). - **Maximum**: Same as adult dose. ## Safety Information ### Contraindications - **Absolute**: Known hypersensitivity to artemether, lumefantrine, or excipients. - **Absolute**: Concurrent use with drugs known to prolong QT interval (e.g., specific antiarrhythmics, antipsychotics, antidepressants). - **Absolute**: Patients with history of congenital QT prolongation or family history of sudden death. - **Absolute**: Severe hepatic impairment (limited data). ### Common Adverse Effects - **Very Common (>10%)**: Headache, dizziness, anorexia, nausea, vomiting, abdominal pain, asthenia, fever. - **Common (1-10%)**: Palpitations, cough, rash, pruritus, arthralgia, myalgia, fatigue. - **Serious but Rare**: QT prolongation (can lead to arrhythmias), severe hypersensitivity reactions (anaphylaxis). ### Key Drug Interactions - **QT-prolonging drugs**: **Avoid co-administration** (e.g., quinidine, amiodarone, cisapride, pimozide, certain macrolides, fluoroquinolones). Increased risk of additive QT prolongation. - **Strong CYP3A4 Inducers**: **Avoid co-administration** (e.g., rifampin, carbamazepine, phenytoin, St. John's Wort). May significantly decrease artemether/lumefantrine levels, leading to treatment failure. - **Strong CYP3A4 Inhibitors**: Use with caution (e.g., ketoconazole, ritonavir). May increase artemether/lumefantrine levels. - **Ritonavir-boosted protease inhibitors**: **Avoid concurrent use** due to complex and significant interactions. - **Mefloquine**: Administer artemether/lumefantrine at least **12 hours after** mefloquine. - **Hormonal Contraceptives**: May reduce efficacy; advise use of a **backup birth control method**. ## Monitoring & Follow-up - **Before Treatment**: Baseline ECG (if risk factors for QT prolongation), LFTs (if concerns), assessment of fluid/electrolyte status. - **During Treatment**: Monitor for QTc prolongation (especially with risk factors), resolution of fever and parasitemia, signs of adverse effects. - **Clinical Signs**: Watch for persistent or worsening malaria symptoms, jaundice, significant rash, signs of cardiac arrhythmia (e.g., palpitations, fainting). ## Clinical Pearls - 💡 Administer **with a fatty meal or milk** (e.g., peanut butter, whole milk) to significantly enhance absorption. - 💡 **Complete the full 3-day course**, even if symptoms improve, to ensure parasite clearance and prevent resistance. - 💡 **Not indicated for malaria prophylaxis** or treatment of severe malaria. - 💡 Advise patients about the **risk of dizziness** and to avoid driving or operating machinery if affected. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.