Category	Details
Type of Medicine	Prescription anti-malarial tablet
Health Conditions Prescribed For	Malaria prevention
Active Ingredients	Mefloquine
Brand Names	Lariam
Available Strengths	250mg
Available As	Oral Tablets
Possible Side Effects	Dizziness, Sleep Disturbances, mood changes, nausea
Manufacturers	Roche and other licensed manufacturers

What is Lariam (Mefloquine)?

Lariam is a prescription antimalarial tablet containing the active ingredient mefloquine hydrochloride. It is used to prevent malaria in adults travelling to areas where the malaria parasite is present and resistant to other medicines.

Lariam works by interfering with the malaria parasite’s ability to grow and multiply in the blood. It is taken once a week, which makes it convenient for long trips when daily tablets might be difficult to remember.

What is Lariam Used For?

Malaria Prevention: Lariam is prescribed for adults who are travelling to malaria-risk regions, such as parts of Africa, Asia, and South America, where the parasite remains sensitive to mefloquine.
Not for Treatment: At 123Meds we supply Lariam only for prevention of malaria. It is not used to treat an active malaria infection.

How Lariam Works

Mefloquine targets the malaria parasite during the red-blood-cell stage of its life cycle.

Blocks Parasite Growth: It interferes with the parasite’s ability to reproduce inside red blood cells, stopping the infection from taking hold.

Long Half-Life: Its long action allows weekly dosing for convenient prevention.

When to Use Lariam for Malaria Prevention

Begin Lariam at least two to three weeks before entering a malaria-risk area, continue weekly during travel, and for four weeks after leaving the area.

Your prescriber will review your medical history and travel plans to make sure mefloquine is the right option for you.

Can Lariam Be Bought Over the Counter?

No. Lariam is a Prescription-Only Medicine (POM) in the UK. You must have a consultation with a UK-registered prescriber, either in person or through a regulated online service such as 123Meds, to confirm suitability and dosage.

Alternative Antimalarials

If Lariam is not suitable, other prescription options include:

Atovaquone/Proguanil (Malarone): Daily tablet, started 1–2 days before travel and continued for 7 days after return.
Doxycycline: Daily capsule, started 1–2 days before travel and continued for 4 weeks after return.

Your prescriber will recommend the best choice based on your destination, medical history, and tolerance.

Directions: How to Take Lariam

Dose: Adults usually take one 250 mg tablet once a week on the same day each week.

Timing: Start 2–3 weeks before entering the malaria-risk area, continue weekly during travel, and for 4 weeks after leaving.

With Food: Swallow the tablet whole with a meal and a full glass of water to aid absorption.

Missed Dose: If you forget a dose and it’s less than a week late, take it as soon as you remember and then return to your usual schedule. If it’s nearly time for your next dose, skip the missed tablet—never double up.

Lariam Ingredients

Active Ingredient: Mefloquine hydrochloride 250 mg (equivalent to 228 mg base).

Inactive Ingredients: May include microcrystalline cellulose, maize starch, povidone, magnesium stearate, and film-coating agents. Inactive ingredients can vary slightly by manufacturer.

Always read the patient information leaflet (PIL) in your pack for the complete list of ingredients, and to check for any you might be allergic to.

Lariam Side Effects

Most travellers tolerate Lariam well, but some people experience side effects.

Common Effects

Nausea, stomach upset or diarrhoea
Headache or dizziness
Vivid dreams or sleep disturbance

Occasional Effects

Mood changes such as anxiety, depression, or irritability
Balance or coordination problems

Serious—Seek Urgent Help (GP, NHS 111, or A&E)

Severe anxiety, low mood, panic attacks, hallucinations, or thoughts of self-harm
Irregular heartbeat or fainting
Severe allergic reaction (swelling of face/lips, difficulty breathing)

Safety Advice

• Tell your prescriber if you have a history of depression, seizures, or mental health conditions—Lariam may not be suitable.
• Stop the tablets and get medical help immediately if you experience significant mood changes, confusion, or severe dizziness.
• Continue to use mosquito bite precautions (nets, repellent, long sleeves) even while on medication.

What is malaria?
Malaria is a serious tropical disease caused by a parasite (Plasmodium) transmitted through the bite of an infected female Anopheles mosquito. It can lead to severe illness and even be fatal if not treated quickly.
Where is malaria most common?
Malaria is found in many tropical and subtropical regions, including parts of Africa, Asia, Central and South America, and some areas of the Middle East. Always check the latest travel guidance at NHS Fit for Travel.
What are the symptoms of malaria?
Malaria symptoms usually develop 7 to 18 days after being bitten by an infected mosquito. The most common symptoms include high fever and chills, sweating, headache, tiredness, nausea, vomiting or diarrhoea, and muscle aches.
If you develop these symptoms during or after travel to a malaria-risk area, seek medical attention immediately, as malaria can become life-threatening without prompt treatment.
How do malaria tablets work?
Antimalarial tablets help your body kill or suppress the malaria parasite before it can multiply and cause illness. They must be taken before, during, and after travel to an affected area to provide full protection.
What types of malaria tablets are available?
The most commonly prescribed antimalarials are atovaquone/proguanil (Malarone), doxycycline, and mefloquine (Lariam). The best option for you depends on your travel destination, the level of resistance in that region, and your personal medical history. Our clinicians can advise on the most suitable and effective medication for your trip.
When should I start taking malaria tablets?
Start taking the tablets before you enter a malaria area (usually 1–2 days to a few weeks beforehand, depending on the medication). You must continue taking them during your trip and for a set period after leaving the risk area.
Do I still need to avoid mosquito bites if I’m taking antimalarials?
Yes. While malaria tablets significantly reduce your risk, no medication is 100% effective. Always use insect repellent, wear long-sleeved clothing, and sleep under a mosquito net in risk areas.
Are there side effects to malaria tablets?
Some people may experience side effects such as nausea, stomach upset, or skin sensitivity to sunlight. These vary depending on the type of tablet. Always read the patient information leaflet and speak to a clinician if you have concerns.
Can I buy malaria tablets online?
Yes. At 123Meds, you can complete an online consultation, and if suitable, our UK-registered clinicians will issue a prescription. Your medication will then be delivered discreetly to your door.