Mefloquine for malaria prevention

  • These tablets are used to protect against malaria when travelling into areas where there is a malaria risk.
  • They are one of a number of measures that can be taken to reduce the risk of malaria - others include wearing suitable clothing, using insect repellents and sleeping in screened rooms or beds.
  • It is important that you take these tablets for two weeks before you travel, during your stay and for four weeks after you return.

About mefloquine

Type of medicine Antimalarial
Used for To prevent and treat malaria
Also called Lariam®
Available as Tablets

Mefloquine tablets are used to help to prevent and treat malaria. Malaria is a serious infection. It is common in tropical countries such as parts of Africa, Asia and South America. Malaria is a disease which is passed on to humans by infected mosquitoes. A parasite called plasmodium lives inside the stomachs of infected female mosquitoes and is passed on to humans by a bite. Mefloquine works by killing the parasites passed into your body from the bites of infected mosquitoes.

Because the pattern of malaria varies with the part of the world you are travelling to, as well as the season and the type of activity you have planned, you should always obtain the latest advice about malaria prevention from your doctor, pharmacist or travel organiser. A back-packing trip may well require different preventative measures against malaria than a business trip to a city.

Although mefloquine to prevent malaria can only be obtained on a prescription from a doctor, it is not prescribable on the NHS. This means that you will be given a private (non-NHS) prescription and you will be asked to pay for the tablets.

Before taking mefloquine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking mefloquine it is important that your doctor or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have epilepsy or have ever had convulsions (fits).
  • If you have heart problems.
  • If you have ever had depression or any other mental health problem.
  • If you have liver problems.
  • If you are taking other medicines, including those available to buy without a prescription, herbal and complementary medicines.
  • If you have ever had an allergic reaction to any medicine. It is particularly important that you tell your doctor if you have ever had a bad reaction to a medicine called quinine.

How to take mefloquine

  • Before you take mefloquine, read the manufacturer's printed information leaflet from inside the pack. The leaflet will give you more information about mefloquine and any possible side-effects from taking it.
  • Take the tablets exactly as your doctor has told you. The dose to prevent malaria in an adult, is one 250 mg tablet once a week. Your dose will also be on the label of the pack. (If you have malaria and you are taking mefloquine to treat it, your dose will be different to this.)
  • Take the tablets on the same day of each week.
  • Start taking the course of tablets at least two weeks before you travel and continue to take them for four weeks after you return.
  • Take each tablet with plenty of water at a mealtime (or just after some food).
  • If you are giving mefloquine to a child, the dose prescribed will depend on the weight of your child. Check the label carefully to make sure you are giving the correct dose. The tablets can be crushed and mixed with food (such as jam or honey) to make it easier for a child to swallow. If you do this, mix the tablet in the food just before you give it to your child.
  • If you do forget to take a dose, take it as soon as you remember. Do not take two doses together. You should complete the course of these tablets unless you are told otherwise by a doctor.

Getting the most from your treatment

  • These tablets help to prevent malaria, but it is also important that you take the following precautions against being bitten by mosquitoes:
    • Cover up bare areas of arms and legs with long-sleeved, loose-fitting clothing, long trousers and socks. This is especially important if you are outside after sunset, as this is when mosquitoes feed.
    • Use an effective insect repellant spray on your clothing and any area of your skin which is bare.
    • Check your sleeping areas for mosquitoes, and spray the room with an insecticide each evening a couple of hours before going to bed. Pay particular attention to furniture and areas under the bed where insects can hide.
    • If you are sleeping in an unscreened room, use a mosquito net impregnated with an insecticide.
  • Your doctor will discuss with you the possibility of unwanted side-effects. If you develop any changes in your moods, thoughts or behaviour, you should see your doctor before your next dose is due so that you can be given an alternative antimalarial medicine.
  • If you have been advised to have an oral vaccine to protect you against typhoid, you should arrange to have this at least three days before you start taking mefloquine. This is because mefloquine can stop the vaccine from working properly.
  • It is possible that mefloquine may make you feel dizzy and affect your balance. These effects may continue for a while, even after you have stopped mefloquine. Make sure you know how you react before you drive or use machines or tools.
  • Reliable contraception should be used to prevent pregnancy during a course of mefloquine and for three months afterwards. If this affects you, ask your doctor for advice about which forms of contraception are suitable.
  • If you buy any other medicines, check with a pharmacist that they are safe to take alongside mefloquine.
  • If you feel ill or develop a fever or flu-like symptoms while you are travelling or within one year of returning home, you should see your doctor straightaway. This is important, even if you have taken your antimalarial medication correctly.

Can mefloquine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common mefloquine side-effects What can I do if I experience this?
Feeling or being sick, indigestion, abdominal pain, Stick to simple foods, and avoid spicy or rich foods
Diarrhoea Drink plenty of water to replace lost fluid
Feeling dizzy, loss of balance If this happens, do not drive or use tools or machines. This may continue for a while even after you have stopped taking mefloquine
Headache Ask your pharmacist to recommend a suitable painkiller
Difficulties sleeping, feelings of panic, restlessness or anxiety, mood swings, confusion, hallucinations Speak with your doctor as soon as possible (this must be before your next dose is due)

If you experience any other symptoms which you think may be due to this medicine, discuss them with your doctor or pharmacist.

How to store mefloquine

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.