Regular marijuana use could affect a person's ability to stay sedated during surgical procedures that require anesthesia.
In a small study of 250 people, researchers found that those who reported regular marijuana use either with smoking or edibles needed more medication to remain sedated during medical procedures.
The study, published in the May issue of The Journal of the American Osteopathic Association, looked at the medical records of 250 people who underwent endoscopic procedures that required sedation medication.
25 of the records reviewed came from people who said they used marijuana regularly, which was defined as daily or weekly use of marijuana flower or edibles, and 225 of the records came from people who did not report regular use.
The researchers found that people who used marijuana daily or weekly needed 14% more fentanyl, 19.6% more midazolam, and 220.5% more propofol (all medications that are used for sedation) for the full length of their procedures than their counterparts who didn't use as much marijuana.
According to lead study author Dr. Mark Twardowski, the researchers couldn't pinpoint exactly what caused regular cannabis users to need more medication, but they believe marijuana could potentially desensitize some of the body's receptors that allow sedatives to take effect.
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"Our team is hoping some other [researchers] will pick this up and try to tease what the interaction is," Dr. Twardowski told INSIDER.
Too much sedation medication could increase blood pressure or make it hard for patients to breathe on their own
Dr. Twardowski said regular marijuana users don't have to worry about waking up during procedures, since doctors can give them more medication in order to stay sedated, but he did warn of the risks associated with increased doses of these drugs.
"The real risk is suppressing the respiration and shutting off someone's breathing," he said. When a person is sedated during surgery, they are typically able to still breathe on their own since they are still conscious. The more sedation medication a person receives, however, and it could affect their ability to remain conscious and breath independently of a respirator device.
If a person needs a respirator during a procedure, it increases their risks of developing pneumonia, lung infection, and lung damage, according to the National Institutes of Health (NIH).
Large amounts of sedation medication could also cause a person's blood pressure to spike or make it more difficult to wake up following the procedure, but Dr. Twardowski said his team didn't find this specific risk in the patients they studied.
There were caveats to the study. All of the records reviewed came from patients who had their surgeries completed at the same trauma center in Colorado, making the study results difficult to generalize to a larger population. Dr. Twardowski also said that, despite the legal status of recreational marijuana in Colorado, stigma still exists around using the substance and could have led to people underreporting their overall marijuana use.
For this reason, he thinks his study's preliminary findings act as a warning for marijuana users. "[Patients] need to be honest and disclose cannabis use to their providers," he said. "[Doctors] need to encourage honesty because it could affect medical care."
