HealthInfo Waitaha Canterbury

Medicinal cannabis (marijuana)

Tarutaru rongoā

Medicinal cannabis is used to relieve symptoms of a medical condition. It can be in various forms: tablets, spray, drops or tea.

To get medicinal cannabis you need a prescription from a health professional who is a registered prescriber.

These products aren't subsidised so there is a significant cost. Most pharmacies do not hold them in stock and have to order them, so there may be a delay in getting your medicinal cannabis.

Medicinal cannabis is different from recreational cannabis, which is used to give a 'high'.

Cannabis intended for smoking or as a food does not qualify as medicinal cannabis.

Using ordinary cannabis (marijuana)

GPs recommend that you do not try using recreational cannabis, for several reasons.

• You do not know how much of the active ingredients you're getting.
• You do not know what other chemicals may be mixed with the cannabis.
• It has a higher risk of unpleasant side effects.
• It's illegal.

When cannabis-based products are useful

Currently there is not much scientific evidence for medicinal products being safe and effective medicine. Medicinal cannabis is not considered the first option for any medical condition.

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 has not 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 is only limited evidence that it will be helpful.

While there is some evidence that it helps a bit with cancer-related pain, it doesn't always seem to improve quality of life.

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

Currently there is no evidence to support use of cannabis-based products for other conditions such as:

• Anxiety or depressive disorders
• Post-traumatic stress disorder
• Obsessive-compulsive disorder
• Autism
• Inflammatory bowel disease such as Crohn's disease or ulcerative colitis.

However, if other treatments aren't working, your GP may consider using a cannabis-based product. To do this, they may also need to talk to your specialist about it.

Side effects of medicinal cannabis

Cannabis-based products can cause side effects which may differ between people and products.

Common side effects include:

• Nausea (feeling sick)
• Stomach pain and upset
• Dizziness
• Confusion
• Tiredness
• Dry mouth

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

  HealthInfo recommends the following pages

• Ministry of Health – Information for consumers about medicinal cannabis

  Information about medicinal cannabis.

• Healthify He Puna Wairoa – Commonly asked questions about cannabis-based products

  Information about cannabis-based products that may be prescribed to treat medical conditions.

Written by HealthInfo clinical advisers. Last reviewed March 2023.

Sources

Page reference: 431386

Review key: HICAN-431386