Updated on January 3, 2019. Medical content reviewed by Dr. Joseph Rosado, MD, M.B.A, Chief Medical Officer
Asthma makes your airways swell and constrict, interfering with your ability to breathe. People with asthma deal with wheezing, coughing and shortness of breath. In severe cases, an asthma attack can put someone’s life in danger. Treating and controlling asthma is incredibly important — after all, everyone needs to breathe!
You may be surprised to learn some people are interested in using medical cannabis to treat asthma symptoms. After all, doesn’t marijuana smoke hurt your lungs? While it can slightly harm your lungs, it doesn’t hurt them nearly as much as cigarette smoke.
We’ve examined cannabinoids’ effects on asthma symptoms for more than 40 years. In 1976, Williams et al. investigated the impact of THC on asthmatic lungs. They read about marijuana’s ability to open airways in scientific literature. To expand on this knowledge, th5ey wanted to experiment in a clinical setting.
Williams et al. worked with a total of 10 patients with asthma. None of the subjects had previous experience using cannabis, so they didn’t have a built-up tolerance. For three days, the patients randomly received a placebo, THC or a typical inhaler. The researchers checked the subjects’ vitals before and after administering a dose.
The team discovered that THC worked just as well to open the airways as a standard inhaler did. While the inhaler worked more quickly, both doses reached the same level of bronchodilation after an hour.
Another study from the 1970s by Tashkin et al. examined THC’s effect on experimentally induced asthma attacks. Previous studies showed promise of cannabis’ potential to reduce airway constriction in patients with asthma. But, they didn’t involve marijuana’s effect on a patient going through an asthma attack.
Tashkin et al. worked with a total of eight asthma patients during the study. To induce asthma attacks, the team had the patients exercise or breathe in methacholine. They then administered a placebo, THC-free marijuana, marijuana with THC, saline or a standard inhaler. After the dose, they observed the patients’ airway constriction.
The THC-free marijuana and saline did not affect the subjects. But, the cannabis with THC and the inhaler immediately reduced symptoms. Patients who inhaled THC experienced some side effects like light-headedness, but these side effects were generally pleasant. Tashkin et al. were concerned about the impact of smoking marijuana on the lungs, but we now have vaping as an alternative.
Hartley et al. conducted another study observing THC’s bronchodilation ability. Previous research had focused on comparing THC to other drugs. But, this team wanted to compare different doses of THC by their effectiveness for clearing asthma patients’ airways. Since THC can cause psychoactive effects, they sought to find a compromise between small dosage and high impact.
The researchers studied five female patients who had never used cannabis before. Twelve hours before the team conducted a test, the subjects didn’t take any of their airway-clearing medication. For four days, each patient received a dosage of either THC or a placebo. Hartley’s crew then observed the patient for six hours.
Every dosage of THC worked significantly better than the placebo, and 100 milligrams worked the best. While lowering the dosage to 50 milligrams severely reduced THC’s benefits, going up to 200 milligrams didn’t have many more benefits than 100 milligrams. Since the 200-milligram dose also caused more side effects, the team concluded that 100 milligrams were ideal. They decided a small dose of THC could help asthma patients with a lower risk of side effects.
Interested in treating your asthma symptoms with medical marijuana? Check out our guide to asthma and medical marijuana to get an overview of the subject. If you think cannabis medicine could work for you, schedule an appointment with a marijuana-friendly doctor. The doctors in our database can help you qualify for your state’s medical marijuana program.