The study, published January 19 in Health Economics, found a significant reduction in pharmacy-based codeine distribution among states that have legalized cannabis for recreational use. From a public health perspective, it’s a promising finding, continuing to affirm that cannabis is leading people away from prescription opioids, which contribute to more than 10,000 overdose deaths annually.
Codeine has seen a rise in popularity as a recreational drug over the last several years, especially among teens. Users often mix codeine cough syrup with soda (often called Lean, Purple Drank or Sizzurp); while it often leads to a feeling of relaxation and happiness, the feelings are not long-lasting, one reason for the substance’s high potential for abuse.
Generally, codeine (especially in syrup form) is prescribed in conjunction with other medications to reduce coughing and relieve pain.
“A reduction in the misuse of opioids will save lives,” said doctoral candidate and lead author Shyam Raman in a Cornell University blog post discussing the study. “Our research indicates that recreational cannabis laws substantially reduce distribution of codeine to pharmacies, an overlooked potential benefit to legalizing recreational cannabis use.”
The study is believed to be one of the first to separately examine the impact on recreational cannabis laws on shipments of opioids to hospitals, pharmacies and other endpoint distributors. The authors additionally note that the study adds to existing literature by examining the impacts of recreational cannabis laws on prescription opioid dispensing “across all payers and endpoints,” to adjust for important opioid-related policies such as prescribing limits and modeling opioids separately by time.
Ultimately, the research revealed a 267% reduction in pharmacy-based distribution of codeine and as much as a 37% reduction after recreational cannabis laws were in effect for four years or more. There was, however, “a minimal impact” on distribution of other opioids, like oxycodone, hydrocodone and morphine in any setting. The study authors also noted a “minimal impact” on codeine distribution by hospitals, which they say have “less permissive policies than pharmacies.”
Senior author Coleman Drake, of the University of Pittsburgh’s School of Public Health, called these findings particularly meaningful, citing previous studies’ focuses on more potent opioids. Codeine, he said, is “a weaker drug with a higher potential for addiction.”
Drake continued, “It indicates people may be obtaining codeine from pharmacies for misuse, and that recreational cannabis laws reduce this illicit demand.”
W. David Bradford (University of Georgia) and Johanna Catherine Maclean, Ph.D. (George Mason University) were also authors on the study.
Maclean spoke about the similarities and differences between cannabis and opioids based on health, noting that while the two substances can both be used to minimize chronic pain symptoms, they aren’t equivalent when it comes to the impact on an individual’s health. The authors conclude that codeine is particularly likely to be used non-medically; therefore, the findings further support the promise of legal cannabis from a public health perspective.
“Increasing legal access to cannabis may shift some consumers away from opioids and toward cannabis,” Maclean said. “While all substances have some risks, cannabis use is arguably less harmful to health than the nonmedical use of prescription opioids.”
The study follows a number of other recent analyses similarly looking at the impact of cannabis legalization on drug use, prescribed or otherwise. In September 2022, one study found that nearly four out of five patients reported “cessation or reduction in pain medication use” after they began using medical cannabis regularly.
American youth have also been shown to steer away from booze in favor of cannabis over the years, with cannabis use rising 245% since the year 2000 in the U.S., while alcohol use has steadily declined over that same period. Another adjacent outcome, a new federally funded study found that people living in states with legal cannabis experience lower rates of alcohol use disorder, compared to those states where cannabis is still criminalized.