Pharm

Mefloquine

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Mefloquine, Lariam

  • Indications
  1. Prophylaxis or Treatment of Malaria
    1. Preferred Malaria Prophylaxis agent in Chloroquine resistance areas (esp. longterm travel >6 months)
    2. Less commonly used for Malaria treatment
  • Contraindications
  1. Mefloquine resistant Malaria regions (some regions within southeast asia)
  2. History of Epilepsy (Seizure Disorder)
  3. History of major psychiatric disorder
  4. Cardiac conduction abnormalities (esp. QTc Prolongation)
  5. Concomitant Beta Blocker use
  6. First Trimester Pregnancy
    1. May be used in second or third trimester pregnancy
  7. Children under age 3 months
  • Mechanism
  1. Structural analog of Quinine
  • Medications
  1. Mefloquine Tablets: 250 mg
    1. Take with food and full 8 oz glass of water
    2. Tablets may be crushed and mixed with a small amount of water, milk or other liquids
  1. Protocol
    1. Start dosing 1 week before exposure
    2. Complete dosing 4 weeks after exposure
  2. Adult
    1. Mefloquine 250 mg salt (228 mg base) orally once weekly
  3. Child
    1. Weight <9 kg
      1. Mefloquine 5 mg/kg salt (4.6 mg/kg base) orally once weekly
    2. Weight 9 to 19 kg
      1. Mefloquine 1/4 of adult tablet orally once per week
    3. Weight: 20 to 30 kg
      1. Mefloquine 1/2 of adult tablet orally once per week
    4. Weight: 31 to 45 kg
      1. Mefloquine 3/4 of adult tablet orally once per week
    5. Weight: >45 kg
      1. Mefloquine 1 adult tablet (250 mg) orally once per week
  • Dosing
  • Malaria Treatment (CDC Guidelines)
  1. Adult
    1. Dose 1: Mefloquine 750 mg salt (684 mg base)
    2. Dose 2: Mefloquine 500 mg salt (456 mg base) in 8 to 12 hours after first dose
  2. Child
    1. Dose 1: Mefloquine 15 mg/kg salt (13.7 mg/kg base)
    2. Dose 2: Mefloquine 10 mg/kg salt (9.1 mg/kg base) in 8 to 12 hours after first dose
  • Pharmacokinetics
  1. Half-Life: 33 days
  2. Steady state reached
    1. Weekly dose: 7 weeks
    2. Loading dose: 4 days
  • Adverse Effects
  1. Vestibular toxicity
    1. Risk of longterm Vertigo and Tinnitus
  2. Arrhythmia in patients with cardiac conduction defect
    1. QT Prolongation
    2. Sinus Bradycardia
  3. Neuropsychological effects (uncommon 1:200 to 1:500, but is a FDA black box warning)
    1. Insomnia
    2. Nightmares
    3. Anxiety
    4. Irritability
    5. Drowsiness
    6. Dizziness
    7. Tinnitus
    8. Major Depression
      1. Possible increased Suicidality
    9. Psychosis (paranoia, Hallucinations) or Seizures (rare)
      1. Prophylaxis Incidence: <1:10,000
      2. Treatment Incidence: 1:100 to 1:1500
  • Safety
  1. Considered safe in Lactation
    1. However, infant is not protected from Malaria by Breast Feeding (minimal medication in Breast Milk)
  2. Pregnancy Category B
    1. No significant adverse fetal affects in studies (any trimester)
  • Drug Interactions
  1. Avoid Mefloquine for at least 12 hours after last dose of the following
    1. Quinidine
    2. Quinine
    3. Chloroquine
  2. Agents to avoid overall with Mefloquine
    1. Ziprasidone
  3. Agents that decrease Mefloquine levels
    1. Rifampin
  4. Agents that are decreased by Mefloquine
    1. Valproate
  • References
  1. (2013) Presc Lett 20(9)
  2. (2019) Drugs for Malaria Prophylaxis, Med Lett Drugs Ther, p. e104-5
  3. (2023) Presc Lett, Malaria Prophylaxis, Resource #350806
  4. Boudreau (1993) Trop Med Parasitol 44(3):257-65 [PubMed]
  5. Vanhauwere (1998) Am J Trop Med Hyg 58:17-21 [PubMed]
  6. Weimeke (1991) Am J Trop Med Hyg 45:86-9 [PubMed]
  7. Shahbodaghi (2022) Am Fam Physician 106(3): 270-8 [PubMed]