Pharmac has replaced its epilepsy drug - but some patients and families aren't happy about it.

It's switching to a generic form of lamotrigine called Logem, but there's concern Logem lead to seizures in some people.

A 23-year-old New Zealander who switched her epilepsy medication died suddenly on the morning of September 20.

Bella Gubay, who's daughter suffers from epilepsy, told Heather du Plessis-Allan Pharmac's subcommittee made the decision to switch drugs without consulting patients or doctors.

"Our paediatric neurologist is not onboard, and without Medsafe onboard, who staunchly oppose this move, we're not switching our daughter, even if that means paying for the drug ourselves."