In January 2023, the American Society of Regional Anesthesia and Pain Medicine published guidelines recommending that all patients undergoing anesthesia be screened and questioned about cannabis use, including how much and how often they use, how they take it and when they last used it.

One of the largest studies on the effects of cannabis use on sedation, published in the Journal of Osteopathic Medicine, looked at 250 patients undergoing an endoscopy while under anesthesia. Those that reported regular cannabis use required significantly higher doses of anesthesia than nonusers. Another study, published in the journal PLOS ONE, found that daily cannabis users required a higher dose of sedatives prior to an endoscopy than weekly or monthly users.

On a related note, a 2018 study published in the journal Patient Safety in Surgery reported that marijuana use may interfere with painkillers after surgery. The study looked at 261 trauma center patients and concluded that marijuana use, especially chronic use, may affect the pain response to injury and require higher doses of opioids for pain management.