Cannabis users need up to twice the sedation for medical procedures, study suggests
Cannabis is now legal in 10 US states, all of Canada and - like many of the remaining US states - Europe is embracing decriminalisation. As the green tide spreads, so too does the normalisation of cannabis use. According to a United Nations report, the use of the drug increased by 43 per cent in the US between 2007 and 2015.
As the medicinal uses of cannabis are promoted, conversations around the link between cannabis and psychosis have died down. However, one side effect has yet to be considered by many of its users.
A study has found that regular cannabis users may need up to twice the level of sedation, compared to nonusers, for medical procedures. Researchers tested fentanyl, midazolam and propofol - three drugs commonly used for endoscopy.
The study was undertaken by researchers at Community Hospital in Grand Junction, Colorado, and was published in the Journal of the American Osteopathic Association. The researchers initially looked at the medical records of 250 people who had undergone endoscopic procedures in a two-year span. (This time period commenced three years after cannabis had been legalised in Colorado, in 2012.)
It found that, compared to nonusers, those who smoked cannabis or consumed edibles on a daily or weekly basis required 14 per cent more fentanyl, 20 per cent more midazolam and a considerable 220 per cent more propofol to achieve optimum sedation for routine procedures, such as colonoscopies.
“A total of 250 medical records were reviewed from 1 endoscopy centre and 1 endoscopist to minimise the variability in sedation technique for the study purposes,” the authors of the study explain. “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.”
In more granular terms, the study found that it took an average of 44.81 milligrams of propofol for the cannabis users to drift off, while the nonusers required an average of just 13.83 milligrams. Furthermore, a link was found between how heavy a user the patient was and how much of the sedative drugs were required.
“Some of the sedative medications have dose-dependent side effects, meaning the higher the dose, the greater likelihood for problems,” explains lead researcher Dr Mark Twardowski. “That becomes particularly dangerous when suppressed respiratory function is a known side effect.”
With "continued increase in legalisation and use of cannabis, the field of anaesthesia and sedation needs further studies with greater depth," the study explains. It suggests that probing patients on their cannabis intake "can be an important tool for planning patient care and assessing both medication needs and possible risks during endoscopic procedures."
The research is certainly not without its limitations, especially considering that of the 250 patients, 25 were cannabis users. “This study really marks a small first step,” says Dr Twardowski. “We still don’t understand the mechanism behind the need for higher dosages, which is important to finding better care management solutions.”
Furthermore, there may be other factors to consider such as the possible increased likelihood of cannabis users taking other drugs. While the information is certainly eye-opening, a direct causal link has not yet been found between regular cannabis use and the need for higher doses of drugs for medical sedation.
Nonetheless, this is an important and often overlooked potential side-effect of a drug which is becoming increasingly popular. “A strong correlation appears to exist between the regular use of cannabis and the need for increased doses of the sedative medications fentanyl, midazolam, and propofol required in the performance of endoscopic procedures,” the study explains.
“The correlation could prove to be important in making medical decisions related to the sedation of cannabis users,” the conclusion adds. “Knowledge of a patient's use of cannabis prior to sedation can help prepare endoscopists, nurses, and anesthesia providers for the potential need for more medication, increased costs, and possible risks associated with dose-dependent adverse events.”
The use of the drug increased by 43 per cent in the US between 2007 and 2015, according to a United Nations report. However, the legal status of cannabis in the United States remains a complicated topic.
“[It is] an odd situation that the US drove the international prohibition of cannabis and more recently seems to be driving its liberalisation,” drug expert Dr David Morris told VT. “However, that is all at state level. Federally, cannabis use in America is still an offence ... and with Trump making noises about gangs and drugs, there are some interesting tensions there ... or not.”
“I say or not,” Dr Morris continues, “because the legal cannabis industry in the US may have created enough of a distinction between cannabis 'the drug' and cannabis 'the medicine' that many no longer think of cannabis as one 'thing'. So Trump could elevate the 'war on drugs' including cannabis, but also tolerate a legal cannabis industry.”
Ultimately, expressing sovereignty over your own body is as much about protecting it as it is about exercising what many would argue is the right to choose your poison. One would hope that we know certain things, like murder, are wrong regardless of whether they are illegal. However, since the green tide started to spread across America, cannabis use has increased significantly - going at least some way to show how keen we are to take the government’s lead on our health.