The Opposition is calling for answers from the Government about why it took two weeks for the public be told an epilepsy drug switch by Pharmac had been potentially linked to three deaths.
Pharmac on November 15 reversed a decision to move 11,000 patients from more expensive brand of the drug lamotrigine to a generic, Logem, three days after safety agency Medsafe issued a public notice.
While urging patients to continue taking Logem, Medsafe said there had been reports of suspected negative reactions to the change to the new drug by some patients, including three deaths.
"A causal link between brand changes of lamotrigine and the adverse reactions described here has not been established," it said.
• Fourth death linked to Pharmac's epilepsy medication switch
• Logem anti-epileptic drug deaths: Chief Coroner Deborah Marshall to investigate
• Three deaths following epilepsy drug brand switch
• Pharmac knew of epilepsy deaths for weeks but stayed silent
Afterwards it was revealed a fourth death earlier in the year had also been potentially linked to the switch and all four are now being probed by a coroner.
Radio NZ now reports Pharmac, Medsafe and the Minister of Health had all been informed of the deaths by October 29, two weeks before the reversal.
National Party health spokesman Michael Woodhouse says answers are needed about that delay and is repeating calls for a ministerial inquiry into the deaths.
"I think the question is why Pharmac waited. They informed the minister but it was ultimately Pharmac's decision to suspend the drug swap," Woodhouse told reporters on Tuesday.
"There are some very serious questions to ask both of Pharmac and of the minister and why he didn't ask them to act sooner … Why they waited another fortnight is something that needs to be answered and answered quickly."
Woodhouse said his calls for a probe had been ignored.
But Health Minister David Clark defended Pharmac's processes, saying the cases has been worked through carefully to ensure "family privacy".
"It's certainly something I raised with Pharmac and received assurances about on the international evidence base that supported their decision," he said.
"I think it's important that Pharmac makes clinical decisions at arm's length from government so that it's not something that politicians interfere with."
Pharmac had acted out "of appropriate caution" in reversing its decision, he said.
In a statement, the drug-buying agency confirmed it had been notified on October 29.
"Pharmac has very limited information about the reported fatalities and we may not know the details, including whether there is any connection with the funded brand change, until after the coroner's investigations are completed," director of operations Lisa Williams said.
"We considered that, in the context of the level of public concern being expressed, the volume of applications had been relatively low such that it needed to be more widely promoted and widened to make it easier for people on lamotrigine to stay on their current brand, if their doctor thinks they should."
Epilepsy New Zealand chief Ross Smith said there was a feeling of surprise about the delay.
"The epilepsy community would have thought the agency acted a bit more promptly," he said.
"They let people carry on doing what they were doing knowing there had been potentially three deaths at that stage."
Smith said it was important to keep an open mind that the link between the new drug and the deaths had not been proven yet and the coroner's investigation needed to be awaited.
"We don't want to be out pedalling a message that Logem is not a safe drug ... What we are talking about is a small number of people that had adverse reactions," he said.