A look at cannabis, CBD, and blood pressure

A look at cannabis, CBD, and blood pressure
Ask MedicalCannabisMD.com
By David Ostrow, MD
This issue’s column responds to two related questions sent in by readers that illustrate the complexity of understanding how the 100+ active ingredients in whole cannabis produce different effects depending on the genetic strain, how and where it was grown and harvested, an individual’s sensitivity to these different compounds, how much and by what route it was ingested and, as always, the setting in which it is used and what other drugs it may be combined with. To help answer these complex questions, Sunil Aggrawall, PhD, has provided most of the following information from his recently completed thesis on The Medical Geography of Cannabinoid Botanicals in Washington State: Access, Delivery, and Distress, available at sunilaggarwal.net.

Question 1: What is Cannabidiol (CBD) and do its effects on the body differ from THC?

A: There are over 100 compounds in whole cannabis — including at least 108 different cannabinoids (which, structurally, are 21-carbon terphenophenolics), flavonoids, sesquiterpenoids, and phytosterols — all pharmacologically active to varying degrees. A good general rule is that indica strains produce more CBD, and are better for chronic bodily pain and sedation; while sativa strains produce more THC and are better for antidepressant and energizing effects. But, as indicated above, these are only the two best-studied components of whole cannabis and the actual properties and effects of a particular strain or preparation, such as hash or kief, may depend more on the interplay between the total set of active ingredients — what Dr. Ethan Russo calls the “entourage effect.”

That is why medicinal cannabis users often find relief from not just depression or pain, but also inflammation, nausea/vomiting, and muscle spasticity. In addition, basic and clinical researchers are testing whole cannabis and its components for anti-cancer and anti-aging properties.

Question 2: Is cannabis good for controlling blood pressure? Since it can make your heart beat faster, is there a risk of heart attack with cannabis use? A friend once passed out from using cannabis while drunk on wine. It was very scary and made me afraid to combine cannabis with alcohol.

A: Any drug that can lower blood pressure in some individuals and at specific doses, but produce the opposite effect in others or at different doses, is considered “biphasic.” Most often, this is related to dose — one phase of the drug effect predominates at lower doses while the other phase predominates at higher doses. But with whole cannabis, we are dealing with over 100 active compounds, so it is difficult to impossible to predict what dose will have what effect beforehand. Your friend who passed out was probably reacting more to the wine they consumed than to the cannabis. When used alone, cannabis usually causes a mild increase in heart rate (tachycardia) and an insignificant rise in blood pressure.

However, persons with a variety of heart conditions, particularly those with irregular heart rhythms (dysrhythmias) or uncontrolled abnormal blood pressure, can experience more severe changes in heart rate and blood pressure from cannabis, and thus should consult with their cardiologist (who, hopefully, is knowledgeable about the pharmacology of cannabis) before using it. While there are no reported deaths due to cannabis use, there have undoubtedly been persons whose abnormal blood pressure or heart rhythm was worsened by it. This can rarely, if not recognized, lead to a heart attack, stroke or even death.