Scientific statement calls for lifting marijuana’s Schedule 1 status
Cannabis should be removed from Schedule 1 of the U.S. Controlled Substances Act so that it can be better researched, according to a statement by the American Heart Association (AHA).
Regulators should also start standardizing concentrations of THC and CBD content in recreational and medicinal marijuana, according to the AHA writing group led by Robert Page II, PharmD, MSPH, of University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences in Denver.
“A key concern is whether cannabis triggers or potentiates major adverse cardiovascular events such as acute MI and arrhythmias, as well as its impact on cardiovascular risk factors,” they wrote.
The still inconclusive evidence on adverse cardiovascular outcomes presents “an urgent need for carefully designed, prospective short- and long-term studies. Ideally, controlled trials of various forms and routes of administration would be tested, but rigorous study of recreational drugs remains a challenge,” the authors emphasized in a scientific statement published online in Circulation.
Page’s group noted that THC in marijuana is known to have multiple potential cardiovascular effects, as it:
- Stimulates the sympathetic nervous system
- Inhibits the parasympathetic nervous system
- Increases heart rate, myocardial oxygen demand, supine blood pressure, and platelet activation
- Associates with endothelial dysfunction and oxidative stress
Meanwhile, CBD reduces heart rate and blood pressure, improves vasodilation in models of endothelial dysfunction, and reduces inflammation and vascular hyperpermeability in diabetic models.
“Because cannabis consumption increases myocardial oxygen demand and decreases myocardial oxygen supply, patients with underlying ischemic disease could see an increase in angina, particularly when cannabis is smoked,” the authors warned.
“Research on the cardiovascular health effects of cannabis is in its infancy and we need large prospective cohort studies to fully understand the ramifications of regular use of cannabis on cardiovascular health,” commented Salomeh Keyhani, MD, MPH, of the University of California San Francisco School of Medicine, who said she agreed with the AHA’s recommendations.
Growing use of cannabis over the years has been linked to alleviation of pain, cachexia, nausea and vomiting, multiple sclerosis spasticity, and epilepsy.
Yet mechanisms of delivery may tilt the risk-benefit profile of the drug.
The AHA group highlighted the risk of edible marijuana consumption in particular, due to the increased systemic absorption, slower time to onset, and peak effect compared with smoked cannabis.
Vaping should be avoided given recent concerns about e-cigarette or vaping-associated lung injury and potential impurities in products on the market, they added.
“All clinicians (physicians, advanced practice providers, nurses, pharmacists, and others) need greater exposure to and education on the various cannabis products and their health implications during their initial training and continuing education, and they must be alert to the possibility that the use of cannabis or its potent synthetic analogs might be the underlying cause of severe cardiovascular events and pathologies,” Page and colleagues urged.