Mefloquine for Malaria Prevention (Lariam)
Comprehensive guide to using mefloquine (Lariam) safely for malaria prevention during travel to endemic areas.
Mefloquine, commonly known by the brand name Lariam, is an antimalarial medication primarily used to prevent malaria in travelers visiting endemic regions. It acts as a blood schizonticide, targeting Plasmodium parasites responsible for malaria infections, including chloroquine-resistant strains of Plasmodium falciparum and Plasmodium vivax.
About mefloquine
Mefloquine belongs to a class of medicines known as antimalarials. It is indicated for the prophylaxis (prevention) of malaria in areas where the disease is prevalent, such as parts of Africa, Asia, South and Central America, and the Middle East. Malaria is a potentially fatal infection transmitted by the bite of infected female Anopheles mosquitoes, which carry Plasmodium parasites. These parasites enter the human bloodstream via mosquito saliva, invade liver cells, multiply, and then infect red blood cells, leading to symptoms like fever, chills, headaches, and muscle pain.
Mefloquine kills the blood-stage parasites (schizonts) released into the bloodstream, preventing the disease from developing. It is particularly useful for weekly dosing due to its long half-life of 13–30 days, making it suitable for long-term travelers, including those staying over six weeks in high-risk areas. However, it does not provide complete protection; users must combine it with mosquito bite prevention measures.
| Type of Medicine | Used For | Also Called | Available As |
|---|---|---|---|
| An antimalarial medicine | To prevent and treat malaria | Lariam® | Tablets (250 mg) |
Before taking mefloquine
Consult a doctor before starting mefloquine to ensure it is appropriate for your health profile. It is contraindicated in individuals with a history of psychiatric disorders (e.g., depression, anxiety, psychosis), seizure disorders, or cardiac conduction abnormalities, as it can exacerbate these conditions. Avoid if you have known hypersensitivity to mefloquine or related quinolines like quinine or chloroquine.
Pregnant or breastfeeding women should discuss risks; mefloquine is generally avoided in the first trimester unless benefits outweigh risks, and limited data exists for breastfeeding. Inform your doctor of any medications you take, as mefloquine interacts with drugs like beta-blockers, antidepressants, and antiepileptics, potentially altering heart rhythm or efficacy. People with liver disease may require dose adjustments due to impaired metabolism.
- Key Contraindications: Psychiatric illness, epilepsy, severe heart rhythm issues.
- Pregnancy Category: Use only if necessary; start ideally after first trimester.
- Children: Dosing based on weight; not for under 6 months without medical advice.
Baseline ECG may be recommended for those with cardiac history. Start treatment 2-3 weeks before travel to monitor for side effects like neuropsychiatric symptoms (anxiety, dizziness, sleep disturbances).
How to take mefloquine
The standard adult dose for malaria prevention is 250 mg (one tablet) taken orally once weekly. Begin 2-3 weeks prior to travel to allow the drug to reach protective levels and identify any adverse reactions early. Continue weekly dosing on the same day of the week during your trip and for 4 weeks after returning.
Take with food or a snack and a full glass of water to minimize stomach upset. Tablets may be crushed and mixed with jam or honey if swallowing is difficult, but ensure the full dose is consumed. For children, dose is weight-based: 5 mg/kg weekly for those over 5 kg.
| Group | Dose | Start Before Travel | Continue After Return |
|---|---|---|---|
| Adults (>45 kg) | 250 mg weekly | 1-3 weeks | 4 weeks |
| Children (5-45 kg) | 5 mg/kg weekly | 1-3 weeks | 4 weeks |
| <5 kg or <6 months | Consult doctor | N/A | N/A |
If vomiting occurs within 1 hour of dosing, repeat the dose. Missed doses should be taken as soon as remembered, then resume weekly schedule. Do not double dose. For treatment (not prevention), higher doses are used under medical supervision.
Getting the most from your treatment
Mefloquine reduces malaria risk but is not 100% effective. Complement with personal protective measures:
- Wear long sleeves, pants, and socks, especially at dusk and dawn when mosquitoes are active.
- Apply DEET-based insect repellents (20-50% concentration) to exposed skin.
- Sleep under insecticide-treated bed nets in screened rooms.
- Avoid rural areas and travel during peak transmission seasons if possible.
Monitor for malaria symptoms (fever, chills, headache, muscle pain) up to 3 months post-travel, even while on prophylaxis. Seek immediate medical help if symptoms appear, informing providers of recent travel and mefloquine use. In resistant areas, alternatives like atovaquone-proguanil or doxycycline may be preferred.
For long-term use (>6 weeks), regular medical check-ups are advised due to cumulative side effect risks.
Can mefloquine cause problems?
Common side effects include nausea, vomiting, diarrhea, dizziness, headache, and sleep disturbances. Neuropsychiatric effects are significant: anxiety, depression, mood changes, vivid dreams, or rarely psychosis and seizures, particularly in those with predispositions. Cardiovascular effects like irregular heartbeat (QT prolongation) can occur.
Side effects often resolve post-treatment due to the drug’s long half-life, but persistent symptoms warrant medical review. Rare serious reactions include Stevens-Johnson syndrome or liver toxicity.
- Frequent (>10%): Gastrointestinal upset, dizziness.
- Serious (report immediately): Psychiatric symptoms, seizures, heart palpitations.
- Overdose: Can cause seizures, coma; seek emergency care.
Mefloquine use has declined due to side effect profiles; it’s reserved for cases where alternatives are unsuitable.
How to store mefloquine
Store tablets at room temperature (15-30°C), away from moisture, heat, and light. Keep in original packaging out of reach of children. Discard unused medication after travel as per local guidelines; do not flush—use take-back programs. Shelf-life is typically 5 years if unopened.
Important information about all medicines
Never share mefloquine. Complete the full course even if feeling well. Alcohol may worsen dizziness—limit intake. Driving or operating machinery is cautioned until effects are known, due to vertigo risk. Report new symptoms promptly. This is not a substitute for professional advice; consult healthcare providers for personalized guidance.
Frequently Asked Questions (FAQs)
Q: How soon before travel should I start mefloquine?
A: Start 2-3 weeks before travel to build protection and check for side effects.
Q: Can I drink alcohol while taking mefloquine?
A: Limit alcohol, as it may increase dizziness and side effects.
Q: Is mefloquine safe during pregnancy?
A: Avoid in first trimester; use only if essential and under medical supervision.
Q: What if I miss a dose?
A: Take as soon as possible, then resume weekly schedule without doubling.
Q: Does mefloquine protect against all malaria types?
A: Effective against P. falciparum and P. vivax, including resistant strains, but combine with bite prevention.
References
- Mefloquine: Uses, Interactions, Mechanism of Action — DrugBank Online. 2023-10-15. https://go.drugbank.com/drugs/DB00358
- Mefloquine as a prophylaxis for malaria needs to be revisited — PMC (National Center for Biotechnology Information). 2021-07-20. https://pmc.ncbi.nlm.nih.gov/articles/PMC8342532/
- Mefloquine for malaria prevention — Patient.info. 2024-01-10. https://patient.info/medicine/mefloquine-for-malaria-prevention-lariam
- Mefloquine — MedlinePlus (U.S. National Library of Medicine). 2023-05-15. https://medlineplus.gov/druginfo/meds/a603030.html
- Mefloquine (oral route) — Mayo Clinic. 2024-02-01. https://www.mayoclinic.org/drugs-supplements/mefloquine-oral-route/description/drg-20067686
- Mefloquine (Lariam®) — U.S. Department of Veterans Affairs Public Health. 2023-11-05. https://www.publichealth.va.gov/exposures/mefloquine-lariam.asp
Similar Articles
Read full bio of Sneha Tete
