Medication Information Leaflet

​What is this medication for?

Mefloquine is a medication used to prevent malaria. 

Malaria is a disease caused by a parasite (Plasmodium species), which can spread to humans by the bite of an infected female Anopheles mosquito.

How should I take/use this medication?

• The medication is usually taken once every week, preferably on the same day of the week, unless directed otherwise by your pharmacist or doctor.
• This medication should be taken after meals, preferably with a full glass of water.
• Check with your pharmacist or doctor for the correct dose if your weight is 45 kg or below.
• Start two to three weeks before entering the area with malaria risk, and continue to take the medication once a week during the trip. After leaving the area with malaria risk, continue to take the medication for four consecutive weeks after travel or once you return to Singapore. It is important to complete the full course of medication for complete protection.
• If you find it difficult to swallow the tablets, you can crush or mix the medication with small amounts of water, milk or other beverages.
• Do not stop taking your medication before checking with your healthcare professional.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. However, if it is near the time for your next dose, skip the missed dose and go back to your usual schedule. Do not take two doses to make up for the missed dose. 

What precautions should I take?

Inform your healthcare professional if: 

• You are allergic to this medication or any other ingredients of this medication.
• You have an allergy to quinine, quinidine or chloroquine.
• You are pregnant or breast-feeding. Avoid pregnancy and use contraceptives while taking this medication and for 3 months after the last dose.
• You are taking any other medications, including supplements, traditional medications and herbal remedies.
• You have a history of seizures (epilepsy or convulsions) or psychiatric disorders (including depression, generalized anxiety disorders, psychosis and schizophrenia) or heart conduction abnormalities.
• You are taking Mefloquine for a year or longer.

Avoid activities that require a high degree of alertness, sense of balance or performance of skilled tasks until you know how Mefloquine affects you. You may feel dizzy or lose your balance. This could happen for months or years after you stop taking Mefloquine and it can be permanent in rare cases.

What are some common side-effects of this medication?

• You may experience nausea, vomiting and abdominal pain.
  • Take the medication after food to minimise gastric side effects.
  • If you vomit within 30 minutes of taking the medication, take the medication again.
  • If you vomit 30 to 60 minutes after taking the medication, take half the dose of the medication again.
• You may experience headache and insomnia.
  • You should continue taking the medication unless you are unable to tolerate the side effects.
• Most side effects from this medication usually occur before the second dose. 

What are some rare but serious side-effects that I need to seek medical advice immediately?

• Vivid dreams
• Dizziness
• Loss of balance
• Ringing in the ears
• Acute anxiety, depression, restlessness and confusion
• Liver problems
  • Symptoms include dark urine or light coloured stools, nausea, vomiting, loss of appetite, stomach pain, yellowing of your eyes or skin.
• Fast or abnormal heartbeats
• Changes in your eyesight or eye pain
• Drug allergy (symptoms include one or more of the following)
  • Swollen face/eyes/lips/tongue.
  • Difficulty in breathing.
  • Itchy skin rashes over your whole body.

Some side effects of Mefloquine may last for a few months or can last longer and not go away even after the drug is stopped.

If you experience any of the above symptoms, stop taking Mefloquine and inform your doctor right away. You may require a different medication to prevent malaria. 

What food or medication should I avoid when I take this medication?

• Mefloquine may interact with alcohol and increase your risk of experiencing certain side-effects such as dizziness or drowsiness. Limit your alcohol intake while taking Mefloquine and do not drink alcohol on the day you take your Mefloquine tablet.
• Check with your healthcare professional if you had or intend to receive vaccines. Mefloquine might affect how well the vaccines work on you.

Inform your pharmacist or doctor if you are taking any of the medications below:

• Halofantrine (used to treat malaria)
• Ketoconazole (used for fungal infections)
• Quinine (Qualaquin) or Quinidine (used to treat malaria or irregular heart beat)
• Chloroquine (Aralen) (used to treat malaria) 

This is not a complete list of all possible drug interactions with this medication. Check with your healthcare professional if you are unsure.

What else can I do to prevent malaria?

To prevent malaria, you may protect yourself against mosquito bites by:

• Wearing long-sleeved clothing and long trousers between sunset and sunrise.
• Applying insect repellent containing more than 20% DEET (N-Diethyl-meta-toluamide) for adults or 10% and less DEET for children on exposed skin. DEET is a common active ingredient in mosquito repellents.
• Using mosquito coils in the room at night.
• Sleep with mosquito nets around your bed, with the net edges tucked under the bed or sleep in a screened room.
• Spray insecticide where mosquitos may rest. Mosquito larvae survive well in clear, slow-flowing streams.
• Avoid going to an area where malaria is common.

Following these guidelines and medication does not mean that you will not get malaria. If you have a fever or experience chills between 1 week and up to 1 year after your return, you should seek medical attention. Inform the doctor that you have been to a country where malaria is common. Malaria can be effectively treated if discovered early. A delay in treatment may result in serious health problems.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How should I throw away this medication safely?

Pack the medication into a bag and bring it back to the pharmacy where you received the medication from.
 

Disclaimers

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last reviewed on September 2019