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Mefloquine

Lariam · ATC code P01BC02

Also known as: Mefloquin, Meflokin

Key facts
Active substance
Mefloquine
Drug class
Antimalarial
ATC code
P01BC02
Authorisation
authorised nationally; no central EU authorisation
Information as of
2026-10-29

Key facts

Mefloquine is an antimalarial. Per the US prescribing information, it is used to treat mild to moderate acute malaria due to susceptible P. falciparum or P. vivax and to prevent P. falciparum and P. vivax malaria.

What it is used for

  • Mild to moderate acute malaria caused by mefloquine-susceptible P. falciparum (chloroquine-susceptible or resistant) or P. vivax; in P. vivax, follow-up with an 8-aminoquinoline (e.g. primaquine) is needed to prevent relapse
  • Prophylaxis of P. falciparum and P. vivax malaria, including chloroquine-resistant P. falciparum
  • Severe malaria should be treated first with an intravenous antimalarial

Dosing

  • Treatment, adults: five tablets (1250 mg) as a single oral dose, not on an empty stomach, with at least 8 oz (240 mL) of water; if no improvement within 48 to 72 hours, use an alternative
  • Prophylaxis, adults: one 250 mg tablet once weekly on the same day, preferably after the main meal; start 1 week before arrival and continue for 4 weeks after leaving the endemic area
  • Treatment, children: 20 to 25 mg/kg; splitting into 2 doses 6 to 8 hours apart may reduce adverse effects; prophylaxis about 5 mg/kg once weekly – see the full text
  • Hepatic impairment: elimination may be prolonged with a higher risk of adverse reactions

Contraindications

  • Hypersensitivity to mefloquine or related compounds (e.g. quinine, quinidine) or any excipient
  • For prophylaxis: active or recent depression, generalized anxiety disorder, psychosis, schizophrenia or other major psychiatric disorders, or a history of convulsions

Important warnings

  • Neuropsychiatric reactions: anxiety, paranoia, depression, hallucinations, psychotic behavior, suicidal ideation; may persist for months or years after stopping
  • Neurologic reactions: dizziness or vertigo, tinnitus and loss of balance, permanent in some cases; stop prophylaxis if they occur; caution with driving and similar activities
  • Potentially fatal QTc prolongation with halofantrine or ketoconazole (not within 15 weeks of the last mefloquine dose); ECG changes with quinine or quinidine
  • Long-term use: periodic liver tests, neuropsychiatric and eye examinations

Side effects

  • Prophylaxis: vomiting (3%) was most frequent; dizziness, syncope, extrasystoles
  • Treatment: dizziness, myalgia, nausea, fever, headache, vomiting, chills, diarrhea, skin rash, abdominal pain, fatigue, loss of appetite, tinnitus
  • Serious: psychiatric reactions, seizures, encephalopathy, cardiopulmonary arrest (with propranolol)

Interactions

  • Halofantrine, ketoconazole: contraindicated combination because of QTc prolongation
  • Other drugs affecting cardiac conduction (antiarrhythmics, beta blockers, calcium channel blockers, antihistamines, tricyclic antidepressants, phenothiazines) may add to QTc prolongation
  • Anticonvulsants (valproic acid, carbamazepine, phenobarbital, phenytoin): reduced seizure control – monitor levels
  • Live oral typhoid vaccine: complete vaccination at least 3 days before the first dose; rifampin lowers mefloquine levels

Pregnancy and breastfeeding

  • Published studies show no increased risk of birth defects or adverse pregnancy outcomes; use during pregnancy only if clearly needed

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Patient information (US)

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

Austria

  • LariamCheplapharm Arzneimittel Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Brand names in 10 more European countries
Belgium
Lariam
Cyprus
Eloquine
Finland
Lariam
France
Lariam
Italy
Lariam
Luxembourg
Lariam
Netherlands
Lariam
Norway
Lariam
Portugal
Mephaquin Lactab
Sweden
Lariam

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

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Sources

  1. U.S. Food and Drug Administration. Mefloquine Hydrochloride (Teva Pharmaceuticals USA, Inc.) – Prescribing Information, 2025-09-26. DailyMed (NLM), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=09716a24-d7da-42b2-af29-c03a1b6670bd
  2. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  3. Wikidata (CC0): ATC P01BC.

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: U.S. Food and Drug Administration (FDA), prescribing information, via DailyMed (NLM); public domain. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.