Do Regular Marijuana Users Require More Anesthesia?

With marijuana being legalized for both medical and recreational use in many states throughout the United States, more people are now using the drug and the amount is increasing everyday. Ten states have legalized the recreational use of marijuana and twenty-one states have made the use of medical marijuana legal. Between 2007 and 2015, the use of marijuana increased 43% in the United States, where an estimated 13.5% of adults use marijuana, according to a United Nations report. The increasing marijuana use throughout the country is affecting medical care in different ways and is bringing about many questions and studies hoping for more answers. A new study aims to answer the question do regular marijuana users require more anesthesia?

Researchers at Community Hospital in Grand Junction, Colorado performed a study where they collected data from 250 Colorado patients who had colonoscopies and other endoscopic procedures between January 1, 2016, and December 31, 2017, which was years after the state legalized recreational marijuana in 2012. The study, which was published in the Annals of the American Osteopathic Association, compared marijuana users and non-users to see if there was any difference in the amount of anesthesia needed during a procedure.

Results showed that patients who reported using marijuana on a daily or weekly basis required 14% more fentanyl, 20% more midazolam and 220% more propofol to achieve optimum sedation for routine procedures. For example, it took 13.83 milligrams of propofol, on average, for 225 nonusers to be sedated, compared to an average of 44.81 milligrams that was needed by marijuana users.

“Although marijuana use has been legalized for recreational and medical use in many states, it’s been a very poorly studied substance,” said the study’s lead author, Dr. Mark Twardowski, a specialist in internal medicine who is in private practice in Colorado. “So we can’t say it doesn’t have an effect on other medications and substances that patients might be using. Our study demonstrates that it seems to have an effect on at least the classes of medication used for sedation for simple endoscopic procedures.”

Although this study offers some interesting insight, there is still a great amount of research that needs to be done on the topic. It does however, highlight the importance of patients telling their surgeons about marijuana use. Twardowski said “Knowing if someone is using marijuana regularly might affect how we do anesthesia.”