A human study found that Δ9-tetrahydrocannabinol (THC) produced significant bronchodilation in people with stable bronchial asthma. In the double-blind crossover trial, researchers compared smoked marijuana and oral THC with placebo and measured changes in airway function. Oral THC significantly increased specific airway conductance and reduced airway resistance, showing that THC was able to measurably open the airways. The bronchodilator effect lasted for at least two hours, providing early clinical evidence that THC can directly affect respiratory function in people with asthma.
“The acute effects of smoked 2 per cent natural marijuana (7 mg per kg) and 15 mg of oral Δ9-tetrahydrocannabinol (THC) on plethysmographically determined airway resistance (Raw) and specific airway conductance (SGaw) were compared with those of placebo in 10 subjects with stable bronchial asthma using a double-blind crossover technique.
After smoked marijuana, SGaw increased immediately and remained significantly elevated (33 to 48 per cent above initial control values) for at least 2 hours, whereas SGaw did not change after placebo. The peak bronchodilator effect of 1,250 µg of isoproterenol was more pronounced than that of marijuana, but the effect of marijuana lasted longer.
After ingestion of 15 mg of THC, SGaw was elevated significantly at 1 and 2 hours, and Raw was reduced significantly at 1 to 4 hours, whereas no changes were noted after placebo.
These findings indicated that in the asthmatic subjects, both smoked marijuana and oral THC caused significant bronchodilation of at least 2 hours’ duration.”
https://pubmed.ncbi.nlm.nih.gov/4816823
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“After experimental induction of acute bronchospasm in 8 subjects with clinically stable bronchial asthma, effects of 500 mg of smoked marijuana (2.0 per cent delta9-tetrahydrocannabinol) on specific airway conductance and thoracic gas volume were compared with those of 500 mg of smoked placebo marijuana (0.0 per cent delta9-tetrahydrocannabinol), 0.25 ml of aerosolized saline, and 0.25 ml of aerosolized isoproterenol (1,250 mug).
After methacholine-induced bronchospasm, placebo marijuana and saline inhalation produced minimal changes in specific airway conductance and thoracic gas volume, whereas 2.0 per cent marijuana and isoproterenol each caused a prompt correction of the bronchospasm and associated hyperinflation. After exercise-induced bronchospasm, placebo marijuana and saline were followed by gradual recovery during 30 to 60 min, whereas 2.0 per cent marijuana and isoproterenol caused an immediate reversal of exercise-induced asthma and hyperinflation.” 
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“Despite its controversial nature, the use of medical marijuana and cannabis-derived medicinal products grows more popular with each passing year. As of November 2016, over 40 states have passed legislation regarding the use of either medical marijuana or cannabidiol products. Many providers have started encountering patients experimenting with cannabis products for a wide range of conditions. While the debate continues regarding these agents for both medicinal and recreational use in the general population, special consideration needs to be made for pediatric use. This review will deliver the history of marijuana use and legislation in the United States in addition to the currently available medical literature to equip pediatric health care providers with resources to provide patients and their parents the best recommendation for safe and appropriate use of cannabis-containing compounds.” 
“LH-21 is a triazol derivative that has been described as a low-permeant neutral CB1 antagonist, though its pharmacology is still unclear. It has been associated with anti-obesity actions in obese rats. However, its role in preventing type 2 diabetes (T2D) onset have not been studied yet. Given CB1 receptors remain as potential pharmacological targets to fight against obesity and T2D, we wanted to explore the metabolic impact of this compound in an animal model of obesity and pre-diabetes as well as the lack of relevant actions in related central processes such as anxiety. These results suggest that LH-21 can be a new candidate to fight against diabetes onset. Indeed, this compound shows potential in counteracting obesity-related anxiety.”