Is CBD Oil Safe and Beneficial to Take Before Surgery?
Individuals scheduled for surgery should always disclose their CBD or cannabis use to the surgeon and anesthesiologist who would handle the procedure.
Also, patients should ask the presiding surgical doctor if they should be ingesting any cannabinoid at all, and take that advice seriously.
CBD for Anxiety
Some people may be interested in using CBD to manage anxiety before surgery. This interest is understandable since the compound has been shown to possess anti-anxiety characteristics that might benefit those who are anxious about an upcoming operation.
A study published in the Journal of Psychopharmacology found that CBD decreases anxiety levels in individuals with a social anxiety disorder (SAD) with results indicating that, relative to placebo, CBD was associated with significantly decreased subjective anxiety (1).
In the said study, the brain scans showed that CBD regulates chemical uptake and blood flow in the brain.
CBD can help people with anxiety disorders by impacting the CB1 cannabinoid receptors in the brain and modifying the signaling process of serotonin (the “feel-good” chemical) receptors.
However, note that taking CBD too close to a surgery schedule could pose risks, especially since many doctors still do not quite understand the full effects of CBD oil.
CBD vs Anticoagulants
Individuals on any anticoagulant (blood thinner) medication should altogether avoid taking CBD or any cannabis-related product long before going to surgery.
Blood coagulation studies show that CBD showed mild anticoagulating effects (2). Research indicates that CBD can potentially exacerbate bleeding after surgery and slow down wound healing, especially for those who suffer from any clotting disorder.
Whenever one takes CBD or any medicine, it passes through the digestive system to the liver, where an enzymatic pathway, called the cytochrome P450 (CYP450) family of enzymes, metabolizes or breaks down the substance ingested.
Liver enzymes CYP450 process about 60% of all medications, including blood thinners, like warfarin. When used with blood thinners, CBD may decrease how quickly the liver breaks down some medications.
In theory, taking CBD, along with some pharmaceuticals that are broken down by the liver, may increase the concentration and side effects of the drug (3).
A 2017 study showed that CBD is broken down further via the same liver pathways as most prescription anticoagulants (4).
This metabolism is dose-dependent but can affect the potency of the drug. Therefore, those who are taking prescription blood thinners should always consult with their doctor before starting a CBD regimen.
Patients should insist on regular blood checks, as CBD and cannabis can decrease the degradation of the drugs (such as warfarin) in their body, and doses should be adjusted accordingly.
Taking CBD in conjunction with anticoagulants can cause serious complications that may put an individual’s health or life at risk.
CBD vs Anesthetic Risk
Anesthetic risk has many variables and is often related to one’s unique medical issues and specific surgery.
Individuals who use cannabis products do so in many ways, forms and amounts. Thus, CBD’s effect on the body is difficult to predict when combined with a wide variety of anesthetic agents and techniques.
Currently, there is not enough evidence to say that cannabis alone increases one’s anesthetic risk when stopped at an appropriate time.
Still, it is recommended that one abstains from cannabis use as long as possible before surgery.
Below is the minimum time a patient would be expected to stop before receiving an anesthetic, as suggested by the Royal Victoria Regional Health Centre of Canada (5).
|Cannabidiol (CBD)||Cannabis (Marijuana)|
|Oral Dosing/Ingested: Stop 4 hours before surgery||Ingested: Stop 12 hours before surgery|
|Smoked/Vaporized: Stop 12 hours before surgery|
The attending anesthesiologist has a legal obligation to provide patients with the safest care possible during surgery.
However, there may be rare occasions when surgery is delayed, postponed, or canceled at the doctor’s discretion.
Still, under no circumstances shall anyone intoxicated (affected by any drug or alcohol) can receive an anesthetic for non-emergency surgery.
With CBD’s numerous purported therapeutic characteristics, there are several ways that it may benefit individuals in the days before surgery.
However, most experts would suggest avoiding CBD in the hours before a surgical procedure, the same time a doctor recommends avoiding other medications, beverages, and foods.
Thus, those who use CBD regularly or took any CBD in the days before surgery must inform their doctor and their anesthesiologist first.
On the other hand, those who are looking to try CBD for the first time must only do so after consulting with a doctor experienced in cannabis use.
- Crippa JA et al.Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report.J Psychopharmacol. 2011 Jan;25(1):121-30. DOI: 10.1177/0269881110379283. Epub 2010 Sep 9. DOI: 10.1177/0269881110379283.
- Coetzee C, Levendal RA, van de Venter M, Frost CL. Anticoagulant effects of a Cannabis extract in an obese rat model. 2007;14(5):333–337. https://doi.org/10.1016/j.phymed.2006.02.004.
- MedlinePlus. (2020, Jan 21). Cannabidiol. Retrieved from https://medlineplus.gov/druginfo/natural/1439.html.
- Grayson L, Vines B, Nichol K, Szaflarski JP; UAB CBD Program. An interaction between warfarin and cannabidiol, a case report. Epilepsy Behav Case Rep. 2017;9:10–11. Published 2017 Oct 12. DOI:10.1016/j.ebcr.2017.10.001.
- The Royal Victoria Regional Health Centre. (2018, Nov 29). Cannabis Before Surgery. Retrieved from https://www.rvh.on.ca/surgery/SiteAssets/SitePages/preoped/Cannabis%20Before%20Surgery%20Patient%20Information%20Sheet.pdf.