Antimalarial

Mefloquine

Brand names: Lariam

Adult dose

Dose: Prophylaxis: 250mg PO weekly, starting 2–3 weeks before travel, continuing 4 weeks after return. Treatment (P. falciparum): 20–25mg/kg in 2–3 divided doses

Route: PO

Frequency: weekly (prophylaxis)

Clinical pearls

Start ≥2 weeks before travel to allow side-effect assessment
Detailed counselling about neuropsychiatric ADRs (information leaflet mandatory)

Contraindications

History of psychiatric disease (depression, anxiety, psychosis)
History of seizures
Cardiac conduction abnormalities
Hypersensitivity

Side effects

Neuropsychiatric — depression, anxiety, psychosis, suicidality (BLACK BOX, MHRA)
Vivid dreams
GI upset
Cardiac conduction
Hepatotoxicity

Interactions

Antiepileptics (reduced threshold)
QT-prolonging drugs

Monitoring

Mental state
ECG if cardiac risk

Reference: BNF; MHRA Drug Safety Update; UK malaria guidelines; https://bnf.nice.org.uk/drugs/mefloquine/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Pathways