Is mefloquine (Lariam) right for you? Weekly antimalarial explained

Is mefloquine suitable for your trip?

Mefloquine, known by brands including Lariam, is one medicine used to prevent malaria. It is not appropriate for every destination or traveller. A travel-health clinician should check your exact itinerary, local resistance, medical history and other medicines.

CDC destination guidance and the 2026 Yellow Book are useful references, but country recommendations can change. Advice should match the countries and regions you will visit, travel dates, length of stay and planned activities.

What the weekly schedule means

For suitable travellers, CDC prevention guidance describes starting mefloquine at least two weeks before travel, taking it weekly during exposure and continuing for four weeks after leaving the malaria area. The actual prescription depends on the traveller and product.

This timing allows a professional to assess tolerability before departure. It is not an invitation to start tablets without screening. Children need individual assessment and weight-based prescribing; an adult schedule is not a child's dose.

Taking malaria-prevention medicine does not replace bite avoidance. Use appropriate repellents, clothing and mosquito protection as advised for your destination.

Mental-health and neurological screening matters

The CDC and UK guidance identify important psychiatric and seizure restrictions. CDC guidance excludes people with active or recent depression, generalised anxiety disorder, psychosis, schizophrenia, other major psychiatric disorders or seizures, and advises avoiding it with a history of depression. UK guidance uses a broader history-of-psychiatric-disturbance restriction for prevention.

Do not reduce this to one checklist or assume that a relative's condition automatically determines your own eligibility. Give the clinician your personal history, previous reactions, current mental-health treatment and any cardiac conduction problems. The exact local product information governs the prescription.

What to do if symptoms appear

The MHRA warning says that nightmares, acute anxiety, depression, restlessness or confusion during preventive use can signal a more serious reaction. Stop mefloquine and seek medical advice as soon as possible if neuropsychiatric symptoms or changes in mental state develop.

A clinician should arrange replacement prevention and the correct timing. Do not improvise a switch to another antimalarial or assume stopping means your protection is complete. Severe symptoms, seizures or thoughts of self-harm require emergency help.

How alternatives are chosen

Atovaquone-proguanil, doxycycline and other options have different destination, interaction and patient restrictions. A daily-versus-weekly comparison cannot decide which is safest for you. Pregnancy, breastfeeding, kidney problems and age can change the choice.

During or after travel, fever or feeling seriously unwell needs prompt medical assessment. Tell the professional where and when you travelled, even if you took all preventive doses. Do not treat suspected malaria by taking extra prevention tablets.

Information and clinical decisions

This guide provides general information, not a diagnosis or personal treatment plan. Any clinical assessment and prescribing decision rests with an independent clinician. Prescrivia is a technology intermediary, not a medical provider or pharmacy; it does not prescribe, sell or dispense medicines. Assessment does not guarantee a prescription, medicine availability or a health outcome.

Further reading: treatment information.

Read about online consultations and their limits. Service information must not delay urgent local care.

Sources

1. CDC Yellow Book 2026: malaria — Destination-based prevention, weekly timing, psychiatric/seizure restrictions, cardiac cautions and evaluation of illness after travel.
2. CDC: choosing a malaria-prevention drug — Selection depends on itinerary, resistance and individual contraindications.
3. MHRA: mefloquine neuropsychiatric warning — UK history-based psychiatric restrictions and stop/seek-advice instructions for new neuropsychiatric symptoms.
4. UK malaria prevention guidance 2026 — Current UK preventive-drug considerations and warning symptoms, distinct from US CDC guidance.

See the current clinical, legal and language review statuses for this edition. Source checks are editorial work, not approval.