More investigation is needed into sudden unexpected deaths in epilepsy (Sudep), including the possible effects of Pharmac's funded medication brand change, an Auckland doctor says.

Sudep is the leading cause of death in people with uncontrolled seizures, with new research out today showing 166 people died from it in the 10 years to 2016.

It's unknown how people die from a seizure - some researchers say it causes an irregular heart rhythm, while others have shown that breathing difficulties following a seizure can lead to death.

Two-thirds of these people were compliant with their medication. Researchers suspect these numbers are widely unreported.


The New Zealand Medical Journal study comes after four people have died shortly after changing from a branded version of the anti-epilepsy drug lamotrigine to a generic version, Logem.

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Auckland City Hospital neurologist and epilepsy specialist Dr Peter Bergin, who led the study, said it was too simplistic to assume that these deaths were caused by the brand change.

"People have been dying from this condition for many years well before Pharmac made this change, there is clearly a baseline rate where up to 26 people a year have died of Sudep."

He stressed that this study did not rule out the possibility that patients died as a result of the brand change and it was still a "major concern", but it was too early to jump to that conclusion.

"At the moment we don't know enough about the circumstances of Sudep to give confident advice to people about how to lower the risk and much of that comes down to gaps in data collection."

In response to this review, a new database called EpiNet has been launched in a bid to track changes in Sudep rates. Auckland researchers will also be leading a major international case-control study in the hope of learning more about the risks factors and ways to reduce risks.

"We don't want to distress people with epilepsy by saying that there is a risk of dying but we recognise that like motor accidents Sudep is something that does happen so we want to hear about every possible case so we can learn from that.