Mefloquine

Date: November 2024, Version 4

Quick take

Mefloquine can be used in pregnancy if a doctor thinks it is the best option to prevent or treat malaria. This is very important as malaria can be life-threatening to both you and your unborn baby.

What is it?

Mefloquine (Lariam®) is an antimalarial drug. It may be recommended to prevent malaria when travelling to certain areas. It is also occasionally used to treat malaria in people who have caught the infection.

Benefits

What are the benefits of using mefloquine in pregnancy?

Mefloquine can prevent and treat malaria. This is important as malaria infection can be life-threatening and has been linked to stillbirth, preterm delivery, low infant birth weight, and death of the baby after birth.

Risks

What are the risks of using mefloquine in pregnancy?

There are no known risks to your baby. If mefloquine is needed, it should not be avoided just because you are pregnant.

Alternatives

Are there any alternatives to using mefloquine in pregnancy?

Possibly. Other antimalarial medicines are available. However, if mefloquine is recommended, this is because it is the best drug to prevent malaria in the area of travel or is needed to treat a malaria infection.

Women who are pregnant or planning a pregnancy and need to travel should speak to their GP or local travel clinic to find out which antimalarial medicine is best.

No treatment

What if I prefer not to take mefloquine during pregnancy?

If possible, travel to areas with malaria should be avoided during pregnancy. If travel is essential, any recommended antimalarial drugs should be taken as advised by a GP or travel clinic. It is important that these medicines are taken carefully to ensure that they work properly.

As well as taking antimalarial medicines, women should avoid mosquito bites by taking appropriate measures, such as wearing a DEET-based insect repellent, covering up bare skin with clothing as much as possible, avoiding being outdoors at dawn and dusk when mosquitos are most active, and using bed nets which have been treated with insect repellent.

Will I or my baby need extra monitoring?

As part of routine antenatal care in the UK, women are invited for a very detailed scan at around 20 weeks of pregnancy to check the baby’s development. No further scans to check for birth defects will be required due to use of mefloquine, although women who have had a malaria infection in pregnancy will be offered extra monitoring of the baby’s growth and wellbeing.

Are there any risks to my baby if the father has used mefloquine?

There is currently no evidence that mefloquine used by the father can harm your baby through effects on the sperm.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.