Asthma and Medical Cannabis

Asthma and Medical Marijuana

Definition

Asthma is a long-term inflammatory disease, and the symptoms include shortness of breath, wheezing, coughing, chest tightness, bronchospasm and air flow restriction. Attacks are more likely to happen at night, and may become worse after exercise. Some people suffer from exercise-induced asthma aka exercise-induced bronchoconstriction.

Potential Efficacy / Quality of Evidence (Low, Average, High) of Medical Marijuana for Asthma

Average

Cannabinoids, Terpenes/Terpenoids, Strains and Ratios that May Help

THC and pinene. CBD may help as an antispasmodic, preventing the muscles in the lungs from contracting during an asthma attack.

Medical Cannabis Pros

Cannabis is full of anti-inflammatory terpenoids like myrcene, linalool, Delta-3-Carene, and alpha- and beta- pinene. [1]
Cannabis also has anti-bacterial, anti-fungal and anti-microbial terpenoids like camphene and alpha-bisabolol. [2]
Some cannabis terpenes are bronchodilators, helping to open up the airway and/or aid breathing, such as limonene, borneol and eucalyptol.
THC may also be a bronchodilator. [3]
Targeting CB1 and CB2 receptors may present a “novel preventative therapeutic strategy in asthmatic patients” [4] – because both CB1 and CB2 receptors help protect the lungs.
CBD has anti-spasmodic effects, making it can make it easier for asthmatic patients to breathe. Cannabidiol reduces airway inflammation and fibrosis in experimental allergic asthma.

Medical Cannabis Cons

Whilst terpenes like delta-3-carene can be effective anti-inflammatories, they can also sometimes lead to decreases in respiratory frequency. [5] Burning terpenes releases hydrocarbons, which can cause inflammation in the respiratory system.
Smoking cannabis is not ideal for asthma patients. [6]
The terpenes found in cannabis may cause an allergic reaction in some.
Vaporizers can vary in quality
Inhalers may be the ideal ingestion method, as other methods like tinctures and edibles may not be best for sudden asthma attacks. However, inhaler safety still needs to be tested for – cannabinoids work differently from corticosteroids.

More About the Condition

Asthma is a long-term inflammatory disease that can cause shortness of breath, wheezing, coughing, chest tightness, bronchospasm and air flow restriction. Asthma attacks are more likely to happen at night, and may become worse after exercise. Some people may get several attacks a day or week. Allergies, environmental factors (e.g. living in an area with high amounts of dust and pollutants), and genetic factors are thought to cause asthma. Asthma can also be related to allergies/hayfever or chronic pulmonary obstructive disease. Asthma could be an autoimmune condition. [7]

Over 3,500 people die from asthma attacks, or asthma-related causes in the US every year. There are approximately 19.2 million adults and 5.5 million children in the US who have asthma. Asthma is the primary diagnosis for 1.6 million emergency department visits. [8] Asthma sufferers are more likely to contract pneumonia, or suffer other complications arising from cold or flu.

Asthma is usually treated by the use of reliever inhalers (for immediate relief) and preventer inhalers (to prevent asthma attacks from occuring in the first instance). These inhalers contain short- and long- lasting beta 2 agonists like albuterol (ProAir HFA, Ventolin HFA, others) and levalbuterol (Xopenex) and/or steroids like fluticasone (Flovent) or budesonide (Pulmicort). Leukotriene modifiers like montelukast (Singulair), zafirlukast (Accolate) and zileuton (Zyflo) help relieve asthma symptoms for up to 24 hours. Theophylline (Theo-24, Elixophyllin, others) is a daily pill that helps keep the airways open (bronchodilator) by relaxing the muscles around the airways, but is rarely used nowadays. Allergy injections like Omaliizumab (Xolair) may also be used.

Quotes from the Experts

“Cannabis has a bronchodilator effect on the airways and might have an anti-inflammatory effect on asthmatic patients. However, harmful effects on the lungs are mainly attributed to smoking and include airway irritation and the development of chronic bronchitis symptoms.” Jarjou’i A, Izbicki G. Isr Med Assoc J. 2020 Apr;22(4):232-235. https://www.ncbi.nlm.nih.gov/pubmed/32286026 [9]

“CBD seems to be a potential new drug to modulate inflammatory response in asthma.” Francieli Vuolo, Fabricia Petronilho, Beatriz Sonai, Cristiane Ritter, Jaime E. C. Hallak, Antonio Waldo Zuardi, José A. Crippa, Felipe Dal-Pizzol
Mediators Inflamm. 2015; 2015: 538670. Published online 2015 May 25. doi: 10.1155/2015/538670 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4458548/ [10]