A new study commissioned by the European Medicines Agency suggests there may be an increased risk of neurodevelopmental disorders in children fathered by men taking valproate in the three months prior to conception compared with men on other antiseizure medicines.

In the study, around five children in 100 born to fathers treated with valproate around conception were diagnosed with a neurodevelopmental disorder, compared to three in 100 children whose fathers were taking lamotrigine or levetiracetam.

This risk is much smaller than the risk associated with valproate in pregnancy, says the MHRA, which has publicised the outcome of the study as part of its ongoing monitoring of the safety of valproate.

The MHRA advises that, as a precaution, male patients on valproate who are planning a family in the next year should talk to their healthcare professional about their treatment.

There are no implications from the study for the new strengthened safety measures being introduced this month as a result of the safety review into valproate launched in 2022.

These new measures mean that valproate must not be started in new patients (male or female) younger than 55 years, unless two specialists independently consider that there is no other effective or tolerated treatment, or there are compelling reasons that the reproductive risks do not apply.

For the majority of patients, other effective treatment options are available, says the MHRA, but no one should stop taking valproate without advice from their healthcare professional.

All women who could become pregnant and girls who are currently taking valproate will be reviewed at their next annual specialist review, using a revised valproate Annual Risk Acknowledgement Form, which will include the need for a second opinion’s signature if the patient is to continue with valproate.

A similar system will be introduced later in 2024 for male patients currently taking valproate. This follows advice from the Commission on Human Medicines.