People who regularly use cannabis can require more than twice the usual level of sedation when ongoing medical procedures, a new study warns.
"Some of the sedative drugs have dose-dependent side effects, which means that a greater dose, greater probability of problems," said lead researcher Mark Twardowski of Western Medical Associates in Colorado, USA.
"It becomes particularly dangerous when suppressed respiratory function is a known side-effect," added Tvardovski.
For the study, researchers in Colorado examined the medical records of 250 patients who received endoscopic procedures after 2012, when the state legalized recreational cannabis.
Patients who smoked or swallow cannabis on a daily or weekly basis claimed 14 percent more fentanyl, 20 percent more midazolam and 220 percent more propofol to achieve optimal sedation for routine procedures, including colonoscopy, showed the findings published in The Journal of the American association for osteopathy.
"Cannabis has some metabolic effects that we do not understand and patients need to know that the use of cannabis can make other drugs less effective." We see some problematic trends anecdotally and virtually no formal data to get a sense of scope or suggest protocols based on evidence, "Tuvarovski said.
The use of cannabis in the United States increased by 43 percent between 2007 and 2015. About 13.5 per cent of the adult population used cannabis in this period, with the highest increase seen in people aged 26 and over, according to the study.