Substance abuse risk not greater in those using medical marijuana with prescribed opioids

Among people who use medical cannabis for chronic pain, those who also take prescription pain medications are not at increased risk for serious alcohol and other drug involvement, according to a study in the May issue of the Journal of Studies on Alcohol and Drugs.

Although medical cannabis is being used increasingly often as an alternative to opioids for chronic pain, in many patients it is being used in conjunction with opioids. This use has raised concerns that the combination could increase the risk of patients using substances such as alcohol and other drugs as well.

In this study, researchers looked at data from 273 patients at a medical cannabis clinic in Michigan. More than 60 percent of the participants reported also using prescription pain medication within the past month. There were no significant differences in the rate of co-occurring substance use between those who used prescription pain medication and those who did not.

This intersection of medical cannabis and prescription pain medication has not been widely studied, but the results still surprised the researchers, says lead study author Brian Perron, Ph.D., of the School of Social Work at the University of Michigan.

"We expected that persons receiving both cannabis and prescription opioids would have greater levels of involvement with alcohol and other drugs," Perron said. "However, that wasn't the case—although persons who were receiving both medical cannabis and prescription opioids reported higher levels of pain, they showed very few differences in their use of alcohol and other drugs compared to those receiving medical cannabis only."

Overall, subjects in the study reported higher rates of alcohol and other (noncannabis) drug use, both in their lifetime and in the past three months, than in the general population. But use of other drugs—including alcohol, cocaine, sedatives, street opioids, and amphetamines—did not differ between medical cannabis users who took prescription pain medications and those who did not.

Because prescription pain medications carry a more serious risk of addiction or overdose, medical cannabis may be a safer alternative in pain management, assuming that cannabis has efficacy for longer-term analgesia and is used as intended, according to Perron. But communication between doctor and patient is key.

"We actually know very little about who is receiving both medical cannabis and prescription pain medications," said Perron. "Physicians do not actually 'prescribe' medical cannabis—they only certify whether the patient has a qualifying condition, which allows the patient to gain access to medical cannabis. The system of dispensing medical cannabis is completely separate from prescription medications, so physicians may not know whether a given patient is using medical cannabis, how much, and in what form."

Perron points out that this was an observational study, so inferences must be made carefully. But he does conclude that it is important that health care providers become knowledgeable about medical cannabis laws and can have open conversations with their patients, especially as more states give access to cannabis for medical and recreational purposes.

"Managing a pain condition ultimately requires open communication between the health care professional and the patient," said Perron.