Pharmac's set to change another epilepsy drug -- saying the decision is beyond its control.

Current primidone supplier, Apotex, is discontinuing its supply to New Zealand in October.

Pharmac has reached a provisional agreement with medicine supplier Teva - meaning 800 people could have to change brands.

The drug-funding agency's now seeking feedback on the proposal.

Operations director Lisa Williams told Heather du Plessis-Allan getting a different brand is the only option to have ongoing supply of the medicine.

"So the key thing that patients are going to need to do is engage with their doctors or their prescriber about what's the best thing for them to do going forward."

Pharmac came under fire for its communication of brand switches at a coronial inquest into six sudden epilepsy deaths last year.

The inquest found 'no clear evidence' between the deaths and the decision to change the brand of an anti-seizure medicine to a generic form called Logem. 

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