Concerns are being raised as hundreds of Kiwis are forced to switch brands of the epilepsy medication primidone.
The last time an epilepsy drug was changed in New Zealand - lamotrigine - a Coronial inquest was held to decide whether it was linked to six deaths.
Pharmac says the latest switch is out of their control because the supplier is leaving the New Zealand market.
Last year, Newshub revealed Canadian pharmaceutical giant Apotex was pulling out of New Zealand. It's prompted a series of brand switches - epilepsy drug primidone is one causing concerns.
"We know that some people may experience adverse outcomes, many people experience adverse outcomes and worse still a loss of seizure control," says Epilepsy NZ CEO Ross Smith.
Apotex's decision to withdraw from New Zealand follows the mystery murder of its founder and his wife in their home in 2017.
It's left Pharmac scrambling to find new suppliers for 41 medications, including primidone.
"We've been spending our time trying to find alternative treatments and find the best options," says Pharmac director of operations Lisa Williams.
It's secured another supplier, Teva, but it will mean the 800 people taking primidone will need to change brand.
Guidelines in the United Kingdom divide epilepsy drugs into three categories.
Category 3 is medications that can be switched without concern; category 2, which includes lamotrigine, are drugs that should only be changed in consultation with the patient; and category 1, which primidone falls under, recommends patients should not be switched.
"We would expect everybody, including the family and health professionals, to show an abundance of caution here," Smith says.
A recent inquest into the brand switch for another epilepsy drug, lamotrigine, ruled six deaths were not linked to the change in medication, but the coroner said better communication with patients was needed.
Pharmac says lessons have been learned.
"Our main concern is to make people know that this could be a change in the future and they have time to go and visit their general practitioner and talk to them about the options that they have," Williams says.
The current Apotex brand of primidone is available until October.
