Cannabis users may need more than triple the typical amount of anesthesia for medical procedures according to the findings of a new study.
Colorado researchers conducted the study by examining medical records of 250 patients who had an endoscopy. Of those patients, 25 used cannabis regularly between 2015 and 2017. It was found that patients who used cannabis every day or weekly required 220.5 percent higher of a dose of propofol during sedation than patients who did not. Regular consumers also required 14 percent for fentanyl and 19.6 percent more midazolam.
“We were surprised by the extent and consistency of the effect that cannabis use had on the increasing doses needed to achieve adequate sedation for the procedures. The effect was noted for all three of the common sedation medications used. This is particularly interesting, as the medications are from three different medication classes,” said lead author of the study, Dr. Mark Twardowski, doctor of osteopathic medicine. “Cannabis is very poorly studied, and this investigation begins to point out some of the challenges that chronic cannabis use poses.”
The researchers acknowledged that the small sample size in addition to the study requiring patients to be honest about their cannabis use limited the study. Twardoski stated that there simply isn’t enough data to fully understand whether there is a safe dose of cannabis and that patients need to be honest with their physicians before any procedure.
“Cannabis users cannot assume that their use will have no effects on their medical care,” said Dr. Twardowski. “Clearly the fact that use affects the effectiveness of these three medicines certainly raises myriad questions about potential effects on other medications (pain medicines, anxiety medicines etc.).”
“Because cannabis has such a long life in the body, it may take months to ameliorate the effect. Patients absolutely need to inform their providers about cannabis use prior to any procedure.”
Cannabis has been legal in Colorado, where the study was conducted, since 2012, but the researchers think it’s possible that the stigma still surrounding cannabis inhibits people from being honest with their doctors about their consumption habits. As much as patients need to be honest with their doctors, physicians equally need to understand how cannabis affects anesthesia.
“There is only a problem if patients do not tell their doctors that they are consuming cannabis and if doctors do not know the consequences of cannabis use for anesthesia,” said Dr. Winifried Hauser of Klinikum Saarbrucken in Germany.
“Most probably, the number of patients which require increased dosages of anesthetics because of recreational and/or medical use of cannabis will increase due to the legalization of medical or recreational marijuana,” said Hauser who was not a part of the study.
The study has been published in The Journal of the America Osteopathic Association. Dr. Twardowski’s team is currently developing another study to follow up on sedation requirements in addition to pain management following a procedure for regular cannabis consumers compared to non-consumers.