Men taking powerful pills to treat bipolar disorder and epilepsy were warned today about the risk of birth defects in their children.
Safety concerns mean Britons should use contraception when taking valproate, to prevent the “risk of problems in children”.
Health officials have warned men taking the daily pill that it can increase the likelihood of “neurodevelopmental disorders in children.”
They were also urged not to donate sperm during treatment and for at least three months after stopping it.
The “cautionary advice” on valproate side effects follows a safety review by the Medicines and Healthcare products Regulatory Agency (MHRA), which oversees the safety of drugs used in the UK.
Health officials have warned men taking the daily pill, also used to treat bipolar disorder, that it can increase the likelihood of “neurodevelopmental disorders in children.”
The drug calms manic episodes in people with bipolar disorder by blocking nerve signals.
It is also used to prevent seizures in epileptic patients by reducing the amount of electrical activity in the brain that is thought to be the culprit.
Dr Alison Cave, MHRA’s director of safety, said: ‘Valproate is an effective medicine in the treatment of epilepsy and bipolar disorder.
‘Men taking valproate should be aware that there is now evidence of a possible small increased risk of their child having a neurodevelopmental disorder if their partner becomes pregnant while taking valproate.
‘While the risk to a child is lower than the risk associated with a mother taking valproate during pregnancy, we recommend that men taking valproate and their partners follow updated guidelines and use effective contraception.
Patients taking valproate should not stop taking their medication unless directed to do so by a healthcare professional.
‘It is important to attend your next appointment to discuss your treatment plan.’
A study found that children of men who took the pill up to three months before conception had a slightly higher risk of developing learning difficulties than those taking other drugs to prevent seizures, the MHRA said.
A 2022 report found that 315 women have been prescribed sodium valproate during pregnancy since April 2018 and 30 started taking the drug when they were already pregnant, suggesting that pregnant women are still not being given full details of the risks.
Five out of 100 children whose parents took the drug received a diagnosis, compared with three out of 100 who took other drugs.
Healthcare professionals should inform male patients about this risk at their next routine treatment review and other possible treatment options available, they added.
Valproate has been linked to other problems in children born to mothers taking the drug.
The drug has been condemned as the “new thalidomide” because of its risk of causing severe deformities and learning difficulties when taken by pregnant women, a reference to the 1960s morning sickness treatment that caused potentially fatal birth defects.
A damning 2020 report concluded the government had failed the 27,000 women taking valproate because many were unaware of its risks, and then-Health Secretary Matt Hancock apologised on behalf of the NHS.
The risk to children born to fathers taking the drug is “much lower than the risk of neurodevelopmental disorders in children born to mothers” taking it, the MHRA said.
Anyone who has questions should also speak to a health care professional.
Any suspected side effects associated with valproate should be reported through the Yellow Card system.