Q. What is paroxetine?
Paroxetine is a drug that can help with the symptoms of depression, anxiety and obsessive-compulsive disorders. It's one of a group of drugs called selective serotonin reuptake inhibitors (SSRIs). These drugs increase the level of a chemical in your brain called serotonin.
The brand name for paroxetine is Seroxat (marketed as Paxil in the US)
Q. Does paroxetine cause birth defects?
A series of new studies suggests that birth defects are more common in babies whose mothers took paroxetine early in their pregnancy.
The most recent study followed a group of women and recorded the outcomes of their pregnancies. 958 women in the study took paroxetine in the first three months of their pregnancy.
Together these new studies suggest that:
However, this type of study (a cohort study), which follows a group of people, isn't as reliable/scientifically robust as another type of study used to test drugs (a randomised controlled trial). This means that the study can't show for certain that paroxetine causes birth defects.
Q. Why are you saying something now?
We're saying something now because the new research suggests there might be a link between paroxetine and birth defects. Earlier independent studies haven't found any increased risk of birth defects for women who took paroxetine early in their pregnancy.
We have made this information available now so that women can decide with their doctors what is right for them and their baby.
Q. So, is it safe to take paroxetine during pregnancy?
We can't say for certain. We don't have much evidence on how safe it is to take many drugs during pregnancy. This is because testing drugs on pregnant women isn't usually allowed.
We have sought advice on the safety of paroxetine from experts on the Commission on Human Medicines. The Commission on Human Medicines is an independent committee responsible for providing expert advice on drug safety. Based on the available evidence, the Commission considers the risk of birth defects appear to be small. But it agreed there is still a lot uncertainty around the risks of taking paroxetine when you're pregnant.
What we do know is that most women who took paroxetine in the studies had a healthy baby.
Q. What sort of birth defects did the babies have?
The babies affected mainly had heart defects, such as a hole in the heart (doctors call this ventricular septal defect). Sometimes the hole closes by itself, but some babies need surgery.
The study also found problems such as a cleft lip or palate (this is when parts of the mouth don't grow together properly) and problems with the digestive system. For example, some babies were born with a narrowing of the lower part of the stomach, which makes them vomit forcefully (called pyloric stenosis) or with an anus that didn't open properly. Babies with these problems usually need surgery.
There is a small risk of these problems even if you don’t take paroxetine when you are pregnant.
Q. What is the Agency going to do?
We were brought up to date on the latest results from the researchers in early November. Since that time, we've been in discussion with the Commission on Human Medicines about the meaning of the results and how they fit with the results from other studies.
This has led the Agency to:
Urgent work is taking place to obtain more scientific information and to better understand the information we have at the moment. The company are conducting further studies to examine this issue. If anything changes we will publish further advice.
Q. What should women do if they are pregnant and taking paroxetine?
If you are pregnant, you shouldn't stop taking paroxetine without talking to your doctor. It's important to weigh up the possible risks of paroxetine with the need to treat your depression.
Depression often comes back after you stop treatment. It is possible that individual women may need to take paroxetine during pregnancy.
There isn't enough research to say whether switching to another SSRI will lower your chances of having a baby with birth defects.
Q. What should women do if they are taking paroxetine and want to get pregnant?
If you are thinking about trying for a baby, we advise that you talk to your doctor about the possible risks of paroxetine. You and your doctor will need to balance the risks against the benefits of this drug.
Q. Should I switch to another antidepressant?
There isn't enough evidence to say for certain whether the risks of birth defects are lower with other SSRIs. Other SSRIs include:
Guidelines for doctors advise them to prescribe SSRIs to pregnant women only if the benefit to the mother is thought to be greater than the risk to the baby.
A company funded study suggests that birth defects might be a greater problem for paroxetine than for other SSRIs, but it does not prove this.
Q. If I want to stop taking paroxetine, can I stop straight away?
It's important not to stop taking paroxetine suddenly unless your doctor tells you to. If you stop taking paroxetine suddenly, you may get withdrawal symptoms. These can include nausea, dizziness and headaches. Other withdrawal symptoms are sweating, problems sleeping and a return of your depression or anxiety.
Your doctor can help you reduce your dose gradually over several weeks. This is to reduce the risk that you'll get withdrawal symptoms.
Q. But isn't my baby at risk if I keep taking paroxetine?
There's still considerable uncertainty about the risks, if any, of taking paroxetine during pregnancy. The new study does suggest that birth defects are slightly more common in babies born to women taking paroxetine. But it doesn't prove that paroxetine caused the problems. Also, most women who took paroxetine had a healthy baby. And every woman has a small risk of having a baby with an abnormality whether she takes paroxetine or not.
If you take paroxetine while you are pregnant, doctors will need to closely monitor your baby for at least 24 hours after he or she is born. This is because some babies get withdrawal symptoms [such as irritability, constant crying, sleeping problems and breathing difficulties], especially if their mother took paroxetine in the last three months of her pregnancy.
Q. What if my partner is taking paroxetine?
These studies did not examine the risk of birth defects in babies whose fathers took paroxetine. There is no clear evidence to suggest that babies are more likely to have birth defects if their father took paroxetine.
Q. Does this information apply to women in the later stages of pregnancy?
These new studies included women who took paroxetine in the early stages of and/or throughout pregnancy. It is during the early stages (first three months) that most of the baby’s organs and limbs are either formed or well on the way to being formed and therefore the baby may be more susceptible to potentially harmful effects of some medicines.
Some studies suggest that use of paroxetine in the later stages of pregnancy may result in withdrawal symptoms or serotonergic effects in the newborn baby. Careful monitoring of the baby is recommended in these circumstances.
Q. Breastfeeding
Very small amounts of paroxetine can be found in the breast milk. However, if you are taking paroxetine you should talk to your doctor before you start breastfeeding
Q. Can the defects be picked up on scans?
You should discuss with your doctor or midwife about whether it is necessary for you to have additional ultra sound examinations.
Q. What does the MHRA do?
The MHRA is a Government agency which is responsible for ensuring that medicines and medical devices work, and are acceptably safe. We keep watch over medicines and devices, and take any necessary action to protect the public promptly if there is a problem.
In keeping with our aim to protect the public's interests, the Agency also works to make sure that the public is kept informed and updated on the best scientific evidence and advice on drug safety issues.