Adding Marijuana To State Prescription Drug Monitoring Programs Reduces Prescribing Of Scheduled Narcotics, Study Shows

A new report examining the effects of adding medical marijuana to state prescription drug monitoring programs (PDMPs) finds that the additional tracking had mixed effects, both reducing the prescription of medications that could cause complications with cannabis and also exposing a possible bias against medical marijuana patients among healthcare providers.

On one hand, says the research article, published this month in the journal Health Economics, adding medical marijuana to state PDMPs appears to have effectively reduced prescribing of medications that are severely or moderately contraindicated with cannabis, meaning the two drugs should not be combined. That’s a good thing for patient safety, reducing the risk of complications.

On the other, the findings also showed what author Shelby R. Steuart, a post-doctoral fellow at the University of Chicago, called an “interesting spillover effect”—namely that healthcare providers were also less likely to prescribe other controlled substances, such as narcotics, to medical marijuana patients.

“This paper demonstrates that adding cannabis to PDMPs influences prescribing and thus has the potential to make cannabis use safer,” the new article says. “Conversely, this work indicates providers may have bias against patients who use cannabis and deny them life-improving medications (like controlled ADHD medication or opioids) on the basis of medical cannabis use.”

PDMPs, as the study describes, “are electronic monitoring programs that track the prescription of controlled substances within states, allowing providers to monitor patients’ prescription of some medications.” Since 2014, nine states have added cannabis to their PDMPs, the paper says.

“PDMPs were popularized during the opioid epidemic as a way to limit the amount of opioids that patients have access to,” explained Steuart in an interview with Marijuana Moment. All states monitor opioids, but individual states have also added medications such as anabolic steroids, certain benzodiazepines and others. “I think states just began to see it as an easy way to monitor who’s having access to what substances,” she said. “And that’s when cannabis started to be added as well.”

Typically, she noted, states that sought to provide a more medicalized, highly regulated form of medical marijuana access opted to add cannabis to PDMPs.

The new research is the first to causally evaluate the relationship between PDMPs that include cannabis and the prescription of other medications, Steuart said, but acknowledged that means the full picture is still developing. “It’s exciting that it’s the first piece of evidence, but it’s only the first piece of evidence.”

The article analyzed strictly medical marijuana and not adult-use programs. It looked at prescribing data from medical marijuana where the the substance was added to PDMPs alongside prescribing data from states where PDMPs didn’t include cannabis. “We’re comparing states with [medical] cannabis on a PDMP to states with just medical cannabis,” Steuart said. “So this is like, within the world of medical cannabis, we see these further declines in the states with PDMPs.”

In states with PDMPs, providers prescribed 14.4 percent fewer “units per prescription” of drugs with serious contraindications with cannabis and reduced prescribing of moderately contraindicated drugs by 7.74 percent, the analysis found.

“For the contraindicated medications, it just looks like prescriptions are getting smaller,” Steuart said, which might mean medications are taken less frequently or at lower doses to reduce risks of complications with cannabis. “That could be positive. It could be that doctors are trying to find a way to get them the mediation they need while maximizing their health and minimizing risk.”

Not only did prescriptions for severely contraindicated medications fall more significantly than moderately contraindicated ones, but they also “appear to be decreasing steadily every year, after cannabis is added to PDMPs,” the study says. “This is noteworthy since severely contraindicated drugs are more dangerous for patients to consume with cannabis than moderately contraindicated medications, which may be an additional suggestion of providers’ responsiveness to the information shock.”

As for controlled substances, Schedule IV medications saw a prescribing rate reduction of 11.4 percent and a reduction of 16.2 percent in units per prescription.

“While there does not appear to be a safety concern regarding combining cannabis with many controlled substances (with the exception of opioids, which are contraindicated for use with cannabis in addition to being controlled substances), prescribing rates of these medications are decreasing,” the research says.

It offers as a possible explanation: “One reason may be that since substances included in the Controlled Substances Act are legally required to have a higher potential for abuse, providers seeing evidence that their patients are using cannabis may trigger fear that patients are seeking medications for abuse, leading providers to decrease their willingness to prescribe controlled substances.”

Steuart told Marijuana Moment the lower prescribing of controlled substances could potentially reflect a lack of training around medical marijuana as well as the pressure on healthcare providers to limit availability of opioids and other potentially dangerous drugs.

“There is a lot of fear and also a lot of punishment just throughout the later years of the opioid epidemic,” the researcher noted. “Providers have been told over and over that they’re giving too much, they’re fueling this epidemic, they are causing a problem—and they don’t want to do that.”

Simultaneously, research suggests that in states with regulated medical marijuana programs, physicians are put in a situation “where they have to manage it in some ways, but they’re given no training on it,” Steuart said.

“I think that’s really the root of the stigma, is just that they are not systematically taught what to do,” she continued. “The ones I’ve talked to, even the ones who do seem to have a lot of stigma [toward medical marijuana], they’re trying to do the best they can.”

Notably, Schedule IV medications, which include the lower-potency opioid tramadol as well as certain benzodiazepines, is “the group of controlled substances that appear to be most affected by adding cannabis to PDMPs,” the research determined. “It is possible that lower potency opioids are considered most substitutable by cannabis.”

The study acknowledges several limitations, including that PDMPs might be redundant if patients “frequently disclose their cannabis use to providers.” Another complicating factor is that many states have legalized adult-use cannabis shortly after legalizing medical marijuana, which in many states has been followed by a decline in formal patient enrollment, presumably because patients are simply making purchases on the adult-use market.

As for what might be done to address any stigma the paper highlights, Steuart suggested that medical schools—even in states where cannabis remains illegal or highly restricted—might begin teaching students more about how to integrate cannabis into their practice. “I think some of the issue arises if you’re trained in, like, Texas, and then you go to work in Washington,” she said.

As for established providers, she added, many are already starting to seek out more information on medical cannabis, for example by attending conferences or through continuing education requirements.

“It takes a little bit to get there. It takes a little bit for the information to diffuse,” Steuart said. “I personally feel like we’re moving in the right direction, generally. It just takes a while for everyone to catch up.”

Past research on medical marijuana programs more have regularly, but not always, found reductions in other medications, though that’s presumably due to the availability of cannabis as an alternative treatment and not necessarily related to PDMPs.

For example, results of a recent study of prescribed medical marijuana for patients with chronic pain and mental health issues observed an association between cannabis use and symptom improvement, with patients reporting decreased use of pain mediations.

Relief offered by cannabis may not be everlasting, however. That report, which was funded by the government of Victoria, Australia, and published in the Journal of Pain and Palliative Care Pharmacotherapy, notes that “by the end of 12-months, some of these benefits appeared to wane.”

Another study published this summer, meanwhile, found that more than half (57 percent) of patients with chronic musculoskeletal pain said cannabis was more effective than other analgesic medications, while 40 percent reported reducing their use of other painkillers since they began using marijuana.

And another found that medical marijuana was associated with reduced prescription drug use and improved well-being and symptom intensity among Appalachian adults who suffer from anxiety, depression, insomnia and chronic pain. The researchers behind that paper urged more cannabis education for healthcare providers, who they said are a main source of information for patients.

In July, New York officials released a report finding that more than 3 in 4 state medical marijuana patients reported that cannabis allowed them to reduce their intake of prescription drugs. That included 2 in 3 (66 percent) who reported that marijuana has specifically “reduced their need for prescription opioids for pain reduction.”

And in November of last year, an article linked legalizing medical marijuana with a “lower frequency” of nonprescribed pharmaceutical opioid use.

Earlier in 2023, a federally funded study found that marijuana was significantly associated with reduced opioid cravings for people using them without a prescription, suggesting that expanding access to legal cannabis could provide more people with a safer substitute.

A separate study last year found that legal access to CBD products led to significant reductions in opioid prescriptions, with state-level drops of between 6.6 percent and 8.1 percent fewer prescriptions.

Another linked medical marijuana use to lower pain levels and reduced dependence on opioids and other prescription medications, while yet another, published by the American Medical Association (AMA), found that chronic pain patients who received medical marijuana for longer than a month saw significant reductions in prescribed opioids.

AMA also released research showing that about one in three chronic pain patients report using cannabis as a treatment option, and most of that group has used cannabis as a substitute for other pain medications, including opioids.

State-level marijuana legalization is associated with major reductions in prescribing of the opioid codeine specifically, too, according to a study that leveraged data from the federal Drug Enforcement Administration (DEA).

A 2022 study similarly found that giving people legal access to medical cannabis can help patients reduce their use of opioid painkillers, or cease use altogether, without compromising quality of life.

There’s also no deficit of anecdotal reports, data-based studies and observational analyses that have signaled that some people use cannabis as an alternative to traditional pharmaceutical drugs like opioid-based painkillers and sleep medications.

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Photo courtesy of Mike Latimer.