The medicine pregabalin has been associated with some reports of breathing difficulties in people taking it, the Medicines and Healthcare products Regulatory Agency (MHRA) said last week.
A recent European review of the safety data around pregabalin (brand name Lyrica) found that the way pregabalin affects the nervous system could cause breathing difficulties in some people.
In epilepsy, pregabalin is used as an add-on treatment for focal seizures. Some people taking this medicine may need a lower dose to reduce the risk of these side-effects.
The MHRA advises that people should speak to their doctor if they notice new or increased problems with their breathing. People should also consult a doctor or pharmacist about other medicines they take as well as pregabalin. This is because some medicines taken with pregabalin may increase the risk of breathing problems.
People should avoid drinking alcohol if taking pregabalin, the MHRA has added.
Epilepsy Action says people should not reduce or stop their medicine without speaking to their doctor first. Reducing or stopping epilepsy medicines can cause breakthrough or worsened seizures.
The MHRA has said it will include new warnings about this possible side-effect in the patient information leaflet for pregabalin.
The MHRA said the review had found a small number of cases worldwide where people experienced breathing difficulties. The majority of cases reported were in older people (over the age of 65).
People may also be more at risk if they have other underlying health problems. These include conditions affecting breathing, the kidneys or the brain.
Pregabalin is also given for pain caused by the nervous system and for anxiety disorder.