Medical Cannabis & Asthma: Should You Use It?

James Kneebone
Written by
James Kneebone
Nov 11, 2023
Last updated:
May 2, 2024

More than 2.5 million Australians report having asthma – around 11% of the population. While asthma is a chronic condition and can’t be cured, there are conventional medicines that are effective at managing it.

However, researchers are also investigating cannabis for its effects on the airways in the lungs and how certain cannabis compounds might one day be used to help manage asthma symptoms.

So far, there isn’t enough evidence to say that medical cannabis is a viable asthma treatment, but there are enough interesting results to warrant further research.

First, it’s important to understand what asthma is, how it’s usually treated and what can trigger it.

What Is Asthma?

Asthma is a chronic condition that affects the airways in the lungs. People with asthma often have trouble breathing – depending on the severity of someone’s asthma, they may struggle to breathe most of the time or only on occasion. When someone has asthma, the airways in their lungs are hypersensitive and are prone to tightening and swelling.

When someone’s airways constrict during an asthma attack, air cannot flow freely through their lungs, making it difficult to breathe. Their airways may also produce excess mucus in response to histamine release, causing further constriction and breathing difficulties.  

The type of asthma someone has depends on what triggers their symptoms and how their asthma presents. Allergic asthma is the most common type, and can be triggered by dust, pollen, mould and food items.

Other types of asthma include:

  • non-allergic asthma – when someone’s asthma is caused by something other than allergens
  • occupational asthma – triggered by chemicals, fumes and air pollution
  • exercise-induced asthma
  • thunderstorm asthma – usually triggered by rye grass pollen during thunderstorm seasons
  • nocturnal asthma – when someone’s asthma worsens at night due to temperature changes, heartburn or dust mites.

How Is Asthma Usually Treated?

People with asthma often take preventative medication and carry quick-relief inhalers. Preventative asthma medications are generally taken daily and are designed to reduce swelling in the airways, making an attack less likely. Some preventative asthma medications are inhaled while others come in pill form. Allergy medications can also help control someone's asthma if they find that their asthma attacks are often triggered by allergies.

People with asthma use quick-relief medications when they need to immediately treat an asthma attack. The most common quick-relief asthma medications are short-acting beta agonists, which are administered via an inhaler and cause bronchodilation, meaning they relax lung muscles and widen the airways.

Quick-relief asthma medications are often inhaled, as this allows them to quickly reach the lungs and provide fast symptom relief. Inhalers are also portable and convenient, making them effective at treating sudden asthma symptoms or attacks.

Does Medical Cannabis Have Any Benefits For Asthma?

There has been some research into how cannabis might benefit people with asthma, but the results aren’t conclusive and most studies are still in the preclinical stage. This means that there isn’t enough evidence to indicate medical cannabis as a treatment for asthma, but the studies that have been done may warrant further research.

For example, some studies suggest that medical cannabis may also be a mild bronchodilator, possibly by binding to cannabinoid receptors in the lungs. Whether this has clinical relevance or any potential use in treating asthma hasn’t been established, as the amount of bronchodilation may be insignificant.

One recent study focused on cannabidiol (CBD) – a non-psychotropic cannabinoid in cannabis – and found that it reduced asthma-associated inflammation in mice. Whether this is relevant to humans needs to be explored further, as currently there are very few human studies on the potential benefits of cannabis for asthma.

Does Medical Cannabis Have Any Risks For People With Asthma?

Much of the research around the risks cannabis has for people with asthma focuses on recreational smoking. Smoking cannabis isn’t approved by the Therapeutic Goods Administration (TGA) as a way of consuming medical cannabis.

This is because of the well-documented risks of smoke inhalation, especially for people with respiratory conditions including asthma. Smoking cannabis also burns away some of the medical compounds, making it less efficient than vaping and other consumption methods.

While vaporising medical cannabis is TGA-approved and safer than smoking, whether vaping poses risks for people with asthma hasn’t been thoroughly researched. If you have asthma, you should consult with your doctor before considering vaping, as inhaling any foreign substances can potentially worsen or trigger asthma.

The same goes for ingestible forms of medical cannabis: since there’s been virtually no recent research on how ingested cannabis might affect asthma, it’s best to stay on the safe side and get your doctor’s opinion on whether medical cannabis may benefit you. Ingestible cannabis also takes a long time to take effect, so any potential benefits might not apply for people who need rapid relief from asthma symptoms.

Living With Asthma

While medical cannabis may have some use as a bronchodilator, we likely won’t be seeing cannabis-based asthma medications any time soon. Medical cannabis in general is still an emerging treatment option, and it takes years of research and clinical trials before new treatments become available.

If you suspect you have asthma, we’d recommend seeing your healthcare provider and discussing treatment options. Asthma is a chronic condition and often requires lifelong treatment, but thankfully the available treatments are often effective and can help people with asthma live fulfilling and healthy lives.

James Kneebone
Written by
James Kneebone
James Kneebone is a distinguished voice in the realm of medical cannabis research and advocacy.

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