Mefloquine

Product Information

• Name: Mefloquine
• Active Ingredient: Mefloquine Hydrochloride
• Strength: 250 mg
• Manufacturer: AA Pharma Inc.

Indications and Clinical Use

• Prophylaxis:
  • Indicated for the prevention of Plasmodium falciparum and P. vivax malaria, including chloroquine-resistant strains.

Contraindications

• Hypersensitivity to mefloquine or related compounds (quinine, quinidine, chloroquine).
• Patients with active depression or history of psychiatric disturbances.
• History of seizures.

Warnings and Precautions

• Neuropsychiatric Adverse Reactions: Can persist long after discontinuation, including depression, anxiety, psychosis, and suicidal ideation.
• Cardiovascular: Caution in patients with cardiac conduction disorders; potential for ECG alterations.
• Hematologic: Cases of agranulocytosis and aplastic anemia reported.
• Hepatic: Extended elimination in hepatic impairment.
• Neurologic: Increased risk of seizures in patients with epilepsy; potential for long-lasting vestibular damage.
• Pregnancy and Nursing: Crosses placenta; minimal excretion in breast milk. Use in pregnancy only if clearly needed.

Drug Interactions

• Antimalarials: Avoid concurrent use with quinine, quinidine, or chloroquine.
• QT Prolongation: Avoid halofantrine and ketoconazole during or within 15 weeks after mefloquine use.
• Anticonvulsants: Potential for reduced seizure control; monitor blood levels.
• CYP3A4 Interactions: Inhibitors (e.g., ketoconazole) can increase mefloquine levels; inducers (e.g., rifampicin) can decrease levels.

Dosing Considerations:

• Mefloquine should be taken with food and at least 8 oz (240 mL) of liquid.
• Tablets can be crushed and suspended in water, milk, or other beverages for those unable to swallow them whole.

Recommended Dose and Dosage Adjustment:

Adult Dosage:

• Prevention: 250 mg once weekly, starting at least one week (preferably 2–3 weeks) before departure, during exposure, and for 4 weeks after leaving.

Pediatric Dosage:

• Prevention: 5 mg/kg once weekly (specific doses provided).

Advantage:

• Weekly dosing.
• Long-term safety data.

Disadvantage:

• Severe intolerance in rare cases; consider testing for tolerability 3 weeks before departure.

Adverse Effects:

• Frequent: Dizziness, headache, sleep disorders, nightmares, nausea, vomiting, diarrhea.
• Occasional: Sensory and motor neuropathies, seizures, abnormal coordination, confusion, hallucinations, emotional problems.
• Rare: Suicidal ideation and suicide.

Unexpected Travel - Loading Dose:

• If unable to start one week before travel, a loading dose can be given to achieve effective blood levels quickly:
• Adults > 45 kg: 250 mg daily for 3 days, followed by standard weekly dosing during exposure and for 4 weeks after leaving the endemic area.
• Schedule:
  • Day 1: 1st Dose
  • Day 2: 2nd Dose
  • Day 3: 3rd Dose
  • Thereafter: Regular weekly doses

Failure of Prophylaxis:

• If prophylaxis fails, physicians should carefully select an alternative antimalarial for treatment.
• Special consideration should be given when using halofantrine (refer to warnings and precautions).

Overdosage

• Symptoms: Exacerbation of adverse reactions, particularly neuropsychiatric and cardiac.
• Management: Symptomatic and supportive care, monitoring cardiac function and neuropsychiatric status.

Storage and Stability

• Store at 15-30°C, protected from moisture.