Proguanil

What is it?

Proguanil (Paludrine^®) is a medicine that is taken to prevent malaria infection. It usually needs to be taken with another antimalarial medicine such as chloroquine, or with atovaquone in a medicine called Malarone^®.

Malaria is a serious illness that is spread by mosquito bites and can result in death. Malaria infection in pregnancy can be dangerous to the health of both mother and baby. Pregnant women are therefore advised to avoid travelling to areas where there is a risk of catching malaria. If you are pregnant or planning a pregnancy and cannot avoid travelling to a high risk malaria area, ask your doctor for advice as soon as possible. It is important that your doctor prescribes a medicine or combination of medicines that are likely to work against the type of malaria that is present in the region you are travelling to. You may need to start taking an antimalarial medicine a few weeks before you travel. Your doctor is the best person to help you decide what is right for you and your baby.

Is it safe to take proguanil in pregnancy?

If you are travelling to certain regions you may be advised to take proguanil. You should not avoid taking proguanil because you are pregnant. The risk of harm to you and your baby from malaria is likely to be far greater than any potential risk from taking proguanil.

No antimalarial medicine is 100% effective and it is very important that you also reduce the chance of being bitten by using insect repellents, mosquito nets, and covering as much skin as possible with clothing, particularly between dusk and dawn. Please read our bump leaflet on insect repellents for more information on which products are advised for use in pregnancy.

Can taking proguanil in pregnancy cause a miscarriage?

There is currently no scientific evidence that use in pregnancy of proguanil or proguanil combination products causes miscarriage. Three studies have investigated this outcome in a total of around 300 women. Malaria infection during pregnancy has however, been shown to increase the risk of miscarriage.

Can taking proguanil in pregnancy cause my baby to be born with birth defects?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.

Proguanil works by blocking folic acid production in the malaria parasite. There is therefore a theoretical concern that proguanil could reduce a woman’s folic acid levels. In pregnancy, folic acid is needed for the normal formation of a baby’s spine and skull.

There is no convincing scientific evidence to suggest that women who take proguanil or proguanil combination products in pregnancy have a higher chance of of having a baby with a birth defect. However, only around 400 women who took proguanil during the first three months of pregnancy have been studied. Because large numbers of women need to be studied (sometimes thousands) before an increased risk of individual birth defects can be ruled out, it is currently recommended that women who need to take proguanil during the first trimester also take high dose folic acid (5 milligrams per day) until week 12 of pregnancy. In the UK high dose folic acid needs to be prescribed by a doctor.

Can taking proguanil in pregnancy cause preterm birth?

Use of proguanil or proguanil combination products in pregnancy has not been shown to cause a baby to be born earlier in either of the two studies that have investigated this. Because rates of premature delivery have been studied in only a small number of women, more research into this subject is required. Studies have however shown that women with malaria infection in pregnancy have a higher chance of preterm birth.

Can taking proguanil in pregnancy cause my baby to be small at birth (low birth weight)?

There is no convincing evidence that use of proguanil or proguanil combination products in pregnancy causes a baby to be smaller than expected at birth. Three studies have investigated this and all showed that women taking proguanil were not at increased risk of having a low birth weight baby (<2,500g) or a baby that was smaller than expected. There are some isolated reports of women who were taking proguanil to treat malaria infections having low birth weight babies. This is, however, thought to be due to the effects of the malaria infection in these women, as malaria in pregnancy is known to increase the risk of having a baby weighing less than 2,500g.

Can taking proguanil in pregnancy cause stillbirth?

No scientific studies have investigated the chance of stillbirth following use of proguanil in pregnancy

Can taking proguanil in pregnancy cause learning or behavioural problems in the child?

A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour. 

One small study of 17 one year old children who had been exposed to proguanil in the womb showed that they were no more likely to have developmental problems than one year olds who were exposed in the womb to other antimalarial medicines.

Because only a very small number of children were included in this study, and there are many aspects of learning and behaviour that have not yet been studied in relation to proguanil exposure in the womb, much more research into this subject is required. It has been suggested that malaria infection during pregnancy might affect a baby’s developing brain, but this too needs to be confirmed in further studies.

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care, most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.

Taking proguanil during pregnancy is not expected to cause any problems that would require extra monitoring of your baby. However, if you have been infected with malaria during your pregnancy your doctor may wish to monitor your pregnancy more closely. 

Are there any risks to my baby if the father has taken proguanil?

No studies have specifically investigated whether proguanil used by the father can harm the baby through affects on the sperm, however most experts agree that this is very unlikely. More research on the effects of drug and medicine use in men around the time of conception is needed.

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.