People who regularly use cannabis “CBD or Marijuana” may need more than twice the usual dose of anesthesia for surgery, a U.S. study suggests.
As a growing number of United States legalize marijuana for medical and recreational use, more patients who use the drug are showing up in operating rooms across the country. To get a clearer picture of how cannabis impacts the effectiveness of different types of anesthesia, researchers studied 250 patients who had minimally invasive procedures requiring anesthesia in Colorado, where recreational marijuana use is legal.
Twenty-five patients, or 10 percent, said they regularly used
cannabis. Compared to other patients, cannabis users needed more than twice as much of the anesthetic propofol, the study found. Cannabis users also needed 14 percent more of the analgesic fentanyl and 20 percent more of the sedative midazolam.
“Cannabis users cannot assume that their use will have no effects on their medical care,” said lead study author Dr. Mark Twardowski of Western Medical Associates in Grand Junction, Colorado.
“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.),” Twardowski said by email.
“Because cannabis has such a long life in the body, it may take months to ameliorate the effect,” Twardowski said. “Patients absolutely need to inform their providers about cannabis use prior to any procedure.”
Most of the patients in the study underwent colonoscopies.