Leflunomide
(Date: October 2022. Version: 4)
This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by the UK Health Security Agency (UKHSA) on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.
Quick read
Leflunomide is not used in pregnancy because experiments in animals have suggested that it might affect the developing baby.
What is it?
Leflunomide (Arava®) is used to treat psoriatic and rheumatoid arthritis.
What are the benefits of using leflunomide in pregnancy?
Leflunomide reduces the symptoms of inflammatory arthritis by stopping the immune system from attacking the joints. However, leflunomide is not recommended in pregnancy as animal experiments suggest that it might cause birth defects.
Leflunomide stays in the body for a long time after treatment is stopped. Women who have taken leflunomide in the last two years and are planning a pregnancy or discover they are pregnant should contact their doctor. They might be offered a treatment to ‘wash out’ leflunomide from the body.
What are the risks of using leflunomide in pregnancy?
It is unclear if there are any risks. While animal experiments suggest leflunomide can cause birth defects, information from human pregnancies does not show this.
There is quite a lot of evidence that women who become pregnant while taking leflunomide, or soon after treatment has stopped, are not at high risk of having a baby with a birth defect if they are given treatment in early pregnancy to ‘wash out’ the leflunomide from the body.
Are there any alternatives to using leflunomide in pregnancy?
Usually. Other drugs that are safer in pregnancy can be used to treat inflammatory arthritis. Some women find that an inflammatory illness improves during pregnancy and so a doctor may advise that treatment can be altered.
Women taking leflunomide who are planning a pregnancy or who become pregnant should arrange to see their doctor or specialist as soon as possible to decide on the best treatment, and also determine whether leflunomide ‘wash out’ treatment is required.
What if I prefer not to take medicines during pregnancy?
Poorly controlled inflammatory disease puts pregnancies at risk as it is linked to miscarriage, preterm delivery, and low infant birth weight. To help reduce the chance of these outcomes and to stop an inflammatory disease from flaring, most women will be advised to take some form of medication during pregnancy.
A doctor will only prescribe medicines when necessary and will be happy to talk about any concerns.
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, although extra growth scans may be offered.
Are there any risks to my baby if the father has taken leflunomide?
The manufacturer of leflunomide suggests that men taking leflunomide should not father a pregnancy until three months after treatment has been stopped and a ‘wash out’ treatment has been given. Men taking leflunomide who are planning to father a pregnancy should speak to their doctor or specialist for advice.
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 allows women with a current or previous pregnancy to create a digitally secure ‘my bumps record’. You will be asked to enter information about your health, whether or not you take any medicines, and your pregnancy outcome. 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 https://www.medicinesinpregnancy.org/Login/ to register.
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General information
Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks. They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.
Medicines use in pregnancy
Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby. There are, however, some medicines that can harm a baby’s normal development. How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.
If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.
When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.
Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.
www.medicinesinpregnancy.org