The mother of the first New Zealander to be granted an exemption to use medicinal cannabis says a decision to allow doctors to prescribe cannabidiol without Ministry of Health approval is a "great day for New Zealand medicine".

Photo: RNZ

The government is lifting restrictions on cannabidiol (CBD), a substance found in cannabis with potential therapeutic value and little or no psychoactive properties.

It means doctors will be able to prescribe products containing CBD without Ministry of Health approval. Cannabidiol is currently a controlled drug under the Misuse of Drugs Act.

Rose Renton, who has lobbied for medicinal cannabis since the death of her son, said she hoped the law change would keep others from suffering the same fate.

Ms Renton's son, Alex, died of severe epilepsy in 2015. He became the first New Zealander to be granted an exemption to use medicinal cannabis a month beforehand.

Today's announcement had been a long time coming, but it was "a great day for New Zealand medicine", she said.

"I know Alex, when he was here, cared about people. He would say this is going to help many people. That's what his memory has become."

She said her son's "outcome could have been very different" had the law been relaxed much sooner.

Photo: Facebook

"It should have been there. It should never have been removed from the medicine cabinet. It should have a first line treatment, not a last line treatment."

And she said she would not stop fighting until medicinal cannabis was available across the board.

"It's still only half the plant. There's a lot of conditions that benefit from the THC [the main psychoactive part]. We've won half the race."

Very few current products will meet standards - Dunne

Associate Health Minister Peter Dunne said the law change was part of a deliberate policy to broaden access to medicinal cannabis in line with standards "to make sure people aren't getting junk, but are getting reputable quality products".

He said it was a move towards legalising medicinal cannabis, but wouldn't "immediately bring about a revolution".

"In the longer term as the international market develops and as more quality products come available, I think it will prove to be beneficial to New Zealand patients."

Strict import and export restrictions on cannabidiol products sourced from other countries would hold back their supply to New Zealand, Mr Dunne said.

And he said there were currently very few products that met the quality standards necessary to be prescribed.

"However, we do know of at least one CBD product in development made to high manufacturing standards that will contain two percent or less of the other cannabinoids found in cannabis," Mr Dunne said.

"Really what today's announcement is about is future-proofing the system ... Once the quality products become available, it means they will be able to be prescribed without any form of ministerial or other interventions."

Law change wins praise

Medical Cannabis Awareness has been pushing for patients to have more access to the drug.

Right now, the charity is advocating for a 12-year-old child who suffers from severe seizures to be given CBD.

Spokesperson Shane Le Brun said the latest move should smooth the road in future.

"This basically removes all the paperwork of having to get peer review, having to go to the ministry for approval. Once these products are more readily available, they'll just be able to [prescribe] them like they hand out Panadol."

He said he believed Mr Dunne was doing as much as he could to push for the full legalisation of medicinal cannabis within the National government.

"They've got to do it in such a way to not damage delicate sensibilities of certain National Party politicians and their conservative support base."

The move has won praise from the Medical Association too.

Its chair, Dr Kate Baddock, said she hoped more products would become available now CBD was easier to prescribe.

"They are an effective pain relief ... the CBDs have very little, if any, effect on the mind. They are medicinal."

And she rejected suggestions that doctors were reluctant to use it to treat patients.

"To be honest, I don't put a lot of stock in it. Most GPs who are in practice ... Baby Boomers grew up in the '60s and '70s. That was when marijuana was widely used."