Effects of Cannabis Use on Sedation Requirements for Endoscopic Procedures, Mark A. Twardowski et al., 2019

Effects of Cannabis Use on Sedation Requirements for Endoscopic Procedures

Mark A. Twardowski, Margaret M. Link,  Nicole M. Twardowski

The Journal of the American Osteopathic Association, 2019 (Published online April 15, 2019).



Context : Cannabis (or marijuana) became legal for recreational use in Colorado in 2012, and this legislation change has created both challenges and opportunities in medicine. More patients are using cannabis, and more patients are now willing to admit cannabis use than in the past, which increases the likelihood that they will be forthcoming about use during medical questioning. Cannabis use may have implications during medical care, including procedural sedation.
Objective : To determine whether regular cannabis use had any effect on the dose of medication needed for sedation during endoscopic procedures.
Methods : A total of 250 medical records were reviewed from 1 endoscopy center and 1 endoscopist to minimize the variability in sedation technique for the study purposes. The cohort was reviewed with regard to age and gender to determine whether differences were present among different groups as to the relative amount of sedation medication required in cannabis users vs nonusers.
Results : Medical records from 250 patients were reviewed, and researchers found that compared with people who did not regularly use cannabis, people who regularly used cannabis required an amount of sedation for endoscopic procedures that was significantly higher (P=.05). The statistical significance persisted when adjusted for age, sex, and use of alcohol, benzodiazepines, and opiates.
Conclusion : Determining cannabis use before procedural sedation can be an important tool for planning patient care and assessing both medication needs and possible risks related to increased dosage requirements during endoscopic procedures.

Keywords : cannabis, endoscopy, marijuana, sedation

Cannabis (or marijuana) has been used both recreationally and medicinally for thousands of years. According to a report1 by the United Nations Office on Drugs and Crime in 2017, global cannabis use in 2015 was estimated to be 183 million people, or 3.8% of the adult population. The largest increase in cannabis use occurred in the United States, where usage increased by 43% between 2007 and 2015. An estimated 13.5% of the adult population used cannabis during this period. The largest increase in use was in people aged 26 years or older. Currently, 10 states (Alaska, California, Colorado, Maine [allowed to possess but not buy], Massachusetts, Michigan, Nevada, Oregon, Vermont, and Washington) and Washington, DC, have legalized cannabis for recreational use, although amounts that are allowed to be carried on a person or personally grown vary from state to state. Thirty-three states have legalized medicinal cannabis.2 These numbers suggest that an ever-increasing population of cannabis users will be seen by medical professionals. It will be important to know how cannabis use may affect medical care and the administration of certain medications, including sedatives and opioids. Current research shows that the half-life of tetrahydrocannabiol, the main component of cannabis, is between 5 and 13 days. Total elimination from the system may take up to 25 days. Hypotheses have been proposed that tetrahydrocannabiol interacts with specific cannabinoid receptors, which could include opioid and benzodiazepine receptors, among other mechanisms of pharmacologic action.3 Thus, the interaction of opioids or benzodiazepines with these receptors in patients who regularly use cannabis may be altered.

Because cannabis is considered a Schedule I drug by the US Drug Enforcement Agency, research has been almost absent regarding its interaction with medications and its effects on patient response to medications. Gaining information on these issues has been further complicated by the hesitance of patients to report use of an illegal substance. Since the 2012 legalization of cannabis in Colorado, more patients use and disclose their use of cannabis.4 With new openness about cannabis use, a question specifically addressing this issue was added to our hospital’s nursing preprocedure questions in January 2015. A trend seemed to emerge that suggested people who regularly use cannabis may require more sedation to complete endoscopic procedures than people who are non- or infrequent users. The availability of the new specific information allowed for a medical record review to be undertaken to help answer this question.

Before initiating the medical record review, a literature search was conducted to procure research available in this area to date. It was evident that research relating to the effects of cannabis use on the dose requirements for sedation medications was lacking. One Australian study5 from 2009 reviewed the induction dose of propofol required in patients using cannabis and compared 30 users with 30 nonusers. The research concluded that cannabis use increased the need for propofol during anesthesia when inserting a laryngeal mask. Two other articles6,7 were single patient case studies, 1 in Pakistan in 2014 and 1 in Berlin in 2015.6,7 The Pakistan case study6 found a possible association with cannabis use and the need for increased anesthesia; the patient was switched from propofol to thiopental for induction of anesthesia when he did not respond to the propofol after a total dose of 300 mg.6 The Berlin case study7 also found an increased need for anesthesia, in particular, propofol and morphine.7 The only US article we found on the topic was not a research article, but an overview of multiple drugs and toxins, including cannabis, that described the effects on the body and potential complications or tolerance to anesthesia in the perioperative setting.8 The objective of the current study was to determine whether self-reported regular cannabis use had any relationship to medication needs during procedural sedation. If so, it could affect patient care and add to the limited knowledge base regarding cannabis use and the potential influence on medication interactions, including increased risks and costs associated with the administration of additional doses of medication.