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Call for Standardization and Quality Assurance for Medical Marijuana Products

Marijuana edible products often are mislabeled, leading to calls to reschedule marijuana and install better oversight of this burgeoning industry.
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Practical Pain Management interviewed Gregory T. Carter, MD, MS; Marghie Giuliano, RPh, CAE; Amanda Reiman, PhD, MSW;  Michael M. Miller, MD; and Ryan Vandrey, PhD, for this article.

New research has added fuel to the ongoing debate about medical marijuana. In a proof-of-concept study, researchers found that many edible medical marijuana products sold in a sample of dispensaries in 3 major metropolitan areas had higher or lower amounts of active ingredients than was indicated on the product labels, placing patients at risk for not achieving the desired medical outcome or experiencing adverse effects, as reported in a recent issue of JAMA.1

“If this study is representative of the medical cannabis market, we may have hundreds of thousands of patients buying cannabis products that are mislabeled,” said lead author Ryan Vandrey, PhD, Associate Professor of Psychiatry and Behavioral Sciences at the Johns Hopkins University School of Medicine, in Baltimore.

Calling for better regulation and oversight of marijuana edibles, Dr. Vandrey and his colleagues noted that patients who consume products that contain more delta-9-tetrahydrocannabinol (THC) than is stated on the label could experience side effects, including anxiety and psychotic reactions. Patients purchasing products that are overlabeled may be undertreated, the authors noted.

Less Than 20% of Products Accurately Labeled

The study assessed the levels of THC and cannabidiol (CBD) in 75 edible cannabis products, including baked goods, beverages, and candy/chocolates. The products were manufactured by 47 different brands and were legally purchased from 3 medical marijuana dispensaries in Seattle, San Francisco, and Los Angeles.

With respect to THC content of the 75 products, 17% were accurately labeled (ie, within 10% of the labeled value), 23% were underlabeled, and 60% were overlabeled. The analysis of CBD content showed that 54 products (59%) had detectable levels of CBD, but only 13 products listed CBD on the label. Of these 13 products, 4 were overlabeled and 9 were underlabeled.

In addition, the median THC:CBD ratio of products with detectable CBD was 36:1; 7 had ratios of less than 10:1; and only 1 had a 1:1 ratio. This finding indicates that most products contained high levels of THC and low relative concentrations of minor cannabinoids, “raising questions about whether there is much difference in therapeutic effect or tolerability of these products compared with dronabinol [Marinol], an FDA-approved medicine containing pure synthesized THC in capsules intended for oral ingestion and manufactured following strict pharmaceutical standards,” Dr. Vandrey said.

“The testing methods utilized in this study have been validated to be accurate in testing cannabis-infused brownies,” Dr. Vandrey continued. “However, it was not possible for the study team to manufacture the variety of food products obtained in the study to confirm the analytical methods are reliable in all food products. This highlights the need to develop standards for analytical testing, in addition to product manufacturing, and also highlights the fact that the plethora of edible products currently available can create difficulties for developing and implementing quality assurance methods,” he said.

No other medicine is “available in such an assortment of preparations … that add unnecessary complexity to manufacturing and testing methods,” said Dr. Vandrey. “There is no reason that cannabis medicine needs to be available in the form of popcorn, soda, chocolate, and lollipops,” which increase the risk that marijuana “will be unintentionally ingested,” he said.

Need to Standardize Medical Marijuana Products

The study illustrates the need to standarize dosing and laboratory testing of medical marijuana products, as is done with pharmacologic agents, experts suggest.

“We are stuck in a catch 22 situation,” said Gregory T. Carter, MD, MS, a physiatrist who specializes in neuromuscular medicine and practices in Spokane, WA. “Standardized products would be easily developed if it were not for federal regulatory and funding limitations. These limitations also have hampered research and led to clinical trials that are generally small and of short duration, particularly when compared to industry-sponsored trials.”

However, Dr. Carter said that the argument that the lack of standardization makes it difficult to dose cannabis can be countered by applying the “principle of beginning therapy with low doses and gradually increasing the dose as tolerated” to maximize benefit and minimize adverse events. Data show that most patients achieve analgesia with average doses of less than 5 grams of marijuana per day, he said. “However, some patients may require a larger amount to obtain relief,” said Dr. Carter, who recommends medical marijuana to selected patients with chronic pain (see Recommending Medical Marijuana for Pain Conditions).

“We have come leaps and bounds in terms of standardization, packaging, labeling, and testing of cannabis products,” noted Amanda Reiman, PhD, MSW, Manager of Marijuana Law and Policy at the Drug Policy Alliance, in Berkeley, CA. “States like California have been self-regulating for the past 20 years, and the evolution that we have seen from a brownie wrapped in cellophane to a brownie that is in a sealed opaque package with the ingredients listed and that has been tested shows how far we have come,” Dr. Reiman said.

“One piece that is still missing … is that there is no third-party verification system in place for laboratories. Dispensaries may have an amazing staff that knows how to work the equipment, but that is not necessarily something that is fluid throughout the industry … in states that are still trying to put their regulations together. Thus, we do still have far to go, and this means that it is really up to us to educate consumers and explain how to titrate the dose, read labels, and think about consumption,” Dr. Reiman said.

“I believe that the standardization will catch up. We’re looking at a practice and behavior that is 5,000 years old and we are just now starting to institute the same type of standardization and technologies of a modern-day industry. [The improvement] is going to be piecemeal, but I think we are definitely headed in the right direction,” Dr. Reiman said.

Ways to Improve Standardization

The expanding use of medical marijuana has created an ”urgent need for regulation and quality control,” according to Dr. Vandrey. “Regulations should be consistent across states where medical cannabis is allowed, and, most importantly, they should be monitored and enforced.”

Typically, food and drugs are regulated by the FDA, but “medicinal cannabis is not recognized by the FDA,” he said. In the absence of federal regulation, he suggested that “states with medical marijuana laws need to account for the quality and testing of medical marijuana products sold to their residents.”

Last updated on: September 21, 2015
First published on: September 1, 2015
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Recommending Medical Marijuana for Pain Conditions