Research finds cannabis consumers may require more sedation

Experts have highlighted the need for doctors to be more aware of their patients cannabis use, as research suggests consumers may require higher levels of sedation.

As cannabis is legalised in more places and usage continues to rise, researchers in Canada said clinicians should be aware of patients’ cannabis consumption, and prepare themselves for increased sedation and the risks that come with it.

It comes as a new study has associated cannabinoid use with increased odds of requiring higher total sedation during gastric endoscopies – a procedure that begins with the insertion of a tube and camera through the throat – than non-users.

The authors of the study conducted a prospective cohort study of 419 adult outpatients undergoing endoscopic procedures at three Canadian centres.

Procedures were conducted under conscious sedation, which leaves the patient relaxed and comfortable but partially conscious during the procedure.

Researchers did not examine its impact on propofol sedation, which is more commonly used in the UK and US so more research would be needed to determine the wider impact of cannabis use on sedation.

“Patients didn’t have increased awareness or discomfort during procedures, but they did require more drugs,” said Yasmin Nasser, MD, PhD, lead researcher on the study and assistant professor at Snyder Institute for Chronic Diseases at the University of Calgary.

Each patient completed two questionnaires, one before the procedure about their cannabis use and another afterwards, indicating their awareness and comfort level during the procedure. The questionnaires were analysed along with details about the use of the sedatives midazolam, fentanyl and diphenhydramine during the procedure.

Cannabis use was associated with increased odds of requiring higher total sedation—defined as more than 5 mg of midazolam, or more than 100 mcg of fentanyl, or the need for diphenhydramine.

Interestingly, cannabis use was not associated with higher use of sedation during colonoscopy. Researchers said this could be because gastroscopy generally requires more sedation than colonoscopy due to the irritation caused in the upper part of the gastrointestinal tract.

Cannabinoid use was not independently associated with fentanyl use or adverse events, nor was it associated with intra-procedural awareness or discomfort, the authors found.

This study looked at whether patients were users or non-users of cannabis, but did not examine the timing, quantity or route of cannabis intake prior to the procedure. Researchers say these variables could be the basis for future studies.