February is National Heart Month: Here’s what we know about medical marijuana and the cardiovascular system
February is National Heart Month! Maitri’s Pharmacy team has put together the below guide for patients who want to use medical marijuana for a qualifying condition, but aren’t sure how it could interact with a pre-existing heart condition. As always, we recommend you consult with your cardiologist and a medical marijuana pharmacist on a dosing regimen that can be safe for you.
Effects of cannabinoids on the cardiovascular system:
As is often the case with medical marijuana, research is limited. However, the studies we do have point to the following.
The endocannabinoid system--our body’s natural receiving system for marijuana cannabinoids--runs from our head to our toes. The heart, specifically, contains CB1 and CB2 receptors.
Typical doses of medical marijuana slightly decrease blood pressure and increase heart rate.
High doses of medical marijuana can increase heart rate 20-50 beats per minute because cannabinoids cause vasodilation (the widening of your blood vessels) which also activates the CB1 and CB2 receptors
Low doses of THC activate the CB2 receptors and have been shown to be cardioprotective
Cannabinoids can dilate blood vessels, improving blood flow, and animal studies suggest that some cannabinoids could prevent or reduce atherosclerosis (hardening of the arteries)
In rodents, ultra-low doses of THC have been shown to limit the damage of heart attack while preserving cardiac function and promoting faster healing
Very high doses of medical marijuana and synthetic cannabinoids could be dangerous to the heart, especially in patients with pre-existing heart conditions.
Inhaled THC could trigger heart attack or irregular heart rhythms in individuals who are unable to tolerate a drop in blood pressure, increased demand on the heart, or a rapid heart rate.
Aside from the acute adverse effects of inhaled medical marijuana in patients with heart disease, some of the compounds in medical marijuana are protective against cardiovascular disease.
Dosing
Our pharmacy team recommends products with a 1:1 THC:CBD ratio for higher risk patients, because CBD can block the THC’s activation of the CB1 receptor. CBD is also cardioprotective.
Medical marijuana, cardiovascular disease, and blood thinners
Although marijuana is believed to temporarily increase blood pressure after use, there is still much debate over the correlation, if any, marijuana use has with cardiovascular disease. This study concluded that “neither cumulative lifetime nor recent use of marijuana is associated with the incidence of cardiovascular disease in middle age.” Another study found that marijuana users may have decreased risks of atrial fibrillation (AFib) and in-hospital mortality.
Some studies do show, however, that there may be a drug interaction between marijuana and common blood thinners. THC, the most well-known cannabinoid in the cannabis plant, inhibits the enzyme that breaks down common blood thinners, causing a higher chance of bleeding by those who use both simultaneously. Patients who consume medical marijuana and take blood-thinners should keep an accurate medication log, as well as consult a physician as to when to medicate with what.
Heart health 101
Early recognition of a heart attack or stroke is critical. Click here to learn more about the warning signs of a heart attack and stroke. If you or someone around you is experiencing any of these signs, call 911 and seek immediate medical attention. The faster treatment is received, the more likely the chances will be positive.
Eating healthy, managing stress, getting enough quality sleep, and quitting smoking can help reduce your risk for heart disease. If you’re looking for tips and motivation to make some healthy lifestyle changes like these, click here.
Studies show that the earlier CPR is started, the greater the chance of survival. CPR is not used just for heart attacks. It can also be life-saving after drownings, severe allergic reactions, choking, drug overdoses and suffocation. Click here to find a CPR training near you.
References
Carbone, Federico, et al. "Cannabinoid receptor type 2 activation in atherosclerosis and acute cardiovascular diseases." Current medicinal chemistry 21.35 (2014): 4046-4058.
Waldman, M., et al. "An ultra-low dose of tetrahydrocannabinol provides cardio protection." Biochemical pharmacology 85.11 (2013): 1626-1633.
Pacher, Pal, et al. "Cardiovascular effects of marijuana and synthetic cannabinoids: the good, the bad, and the ugly." Nature Reviews Cardiology 15.3 (2018): 151. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6064852/pdf/JAH3-7-e009099.pdf
Pacher P, Bátkai S, Kunos G. Cardiovascular pharmacology of cannabinoids. Handb Exp Pharmacol. 2005;(168):599–625. doi:10.1007/3-540-26573-2_20
Coronary Artery Risk Development in Young Adults Study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2228270/pdf/nihms38134.pdf
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