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HealthInfo West Coast-Te Tai Poutini

Medicinal cannabis (marijuana)

There's been a lot of publicity about using cannabis with terminal illness to ease pain, nausea (feeling sick), and other symptoms. However, using cannabis and cannabis-based products for these reasons hasn't been well researched, and in most situations it's not clear that it actually works.

Treatments that contain chemicals extracted from cannabis plants are called cannabis-based products. At the moment, there's only one approved medicinal product (Sativex) that can be used in New Zealand and doctors may need Ministry of Health approval to prescribe it. Even with approval, Sativex isn't funded – anyone using it has to pay the full cost of the medicine.

Using ordinary cannabis (marijuana)

GPs recommend that you don't try using recreational cannabis, for several reasons.

When cannabis-based products are useful

GPs can prescribe cannabis-based products to people with multiple sclerosis. The medicine is used to treat bad muscle spasticity (when your muscles are continually contracted and stiff) if other medicine hasn't helped.

Cannabis-based products can be used in palliative care to treat cancer-related pain, or to treat nausea caused by chemotherapy. However, even in these situations there's only limited evidence that it will be helpful.

While there's some evidence that it helps a bit with cancer-related pain, it doesn't always seem to improve quality of life. Side effects such as dizziness, tiredness, confusion, and a dry mouth are common.

For nausea and vomiting, it doesn't seem any better than standard treatments.

However, if other treatments aren't working, your GP may consider using a cannabis-based product. To do this, they may need to apply to the Ministry of Health for permission, and they may also need to talk to your specialist about it.

If you have any further questions about cannabis or cannabis-based products, talk to your GP.

Written by HealthInfo clinical advisers. Last reviewed March 2019.


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Review key: HICAN-431386