Asthma

It seems counterintuitive that cannabis would help people with asthma breathe more easily. In 1973, Dr. Donald Tashkin and his colleagues at UCLA published a study in the New England Journal of Medicine that showed that cannabis works as a bronchodilator, meaning it opens up the airways in both healthy and asthmatic people. He also found that cannabis “succeeded in reversing experimentally induced asthma, in a manner that was comparable to what could be achieved with a standard therapeutic bronchodilator that was widely used at the time.”¹

Other studies have reported improvement of asthma with cannabinoids:

• THC blocks a compound called acetylcholine, which works to maintain the muscle tone in the airways. This compound also causes tightening of the airways in an asthma attack. When THC binds to the cannabinoid receptor, it prevents the release of this compound and allows the airways to relax.²

Studies show that bronchodilation can be achieved with very small doses of THC.³

Smoking cannabis is not recommended especially for patients with asthma or other lung conditions. Heavy cannabis smoke is associated with increased risk for bronchitis and damage and inflammation of the lining of the airways has been reported in cannabis smokers.⁴

My patients with asthma who initially sought approval to use cannabis for other medical conditions have found, much to their surprise, that their co-existing asthma condition is improved and that they don’t require as much asthma medicine.

I have a few patients in my practice who have significant symptoms of asthma that require them to take a number of daily medications that often cause adverse side effects. For some, despite intensive treatment with the latest asthma medications available, they report ongoing symptoms and occasional flare-ups that require hospital visits. By adding cannabis (not smoked), they report improved control of the asthma symptoms, less flare-ups, less hospitalizations and occasionally less need for asthma medications. In my experience, patients treating asthma with cannabis are using THC-rich cannabis, mostly in low doses with vaporizers, sublingual tinctures or edibles. Some patients find chemovars rich in the terpenoids pinene and limonene, which have bronchodilatory effects, to be quite helpful.

Sources

[←1]

^{Tashkin, Donald P., Bertrand J. Shapiro, and Ira M. Frank. “Acute pulmonary physiologic effects of smoked marijuana and oral Δ 9-tetrahydrocannabinol in healthy young men.” New England Journal of Medicine 289.7 (1973): 336-341.}

[←2]

^{Grassin‐Delyle, S., et al. “Cannabinoids inhibit cholinergic contraction in human airways through prejunctional CB1 receptors.” British journal of pharmacology 171.11 (2014): 2767-2777.}

[←3]

^{Tashkin, Donald P., et al. “Effects of Smoked Marijuana in Experimentally Induced Asthma 1, 2.” American Review of Respiratory Disease 112.3 (1975): 377-386.}

[←4]

^{Tashkin, D. P. “Smoked marijuana as a cause of lung injury.” Monaldi Arch Chest Dis 63.2 (2005): 93-100.}