On average, rates of death resulting from opioid analgesic overdoses are lower in states that allow medical use of marijuana compared with states without such laws. Opioid analgesics, such as OxyContin, Percocet, and Vicodin, are prescribed for moderate-to-severe pain, and work by suppressing a person’s perception of pain.
A new multi-institutional study, published in JAMA Internal Medicine (2014; doi:10.1001/jamainternmed.2014.4005) and led by researchers at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, examined the rates for death caused by opioid overdoses between 1999 and 2010.
Results revealed that annual opioid overdose mortality rate was, on average, 24.8% lower in the 13 states that enacted medical marijuana laws than in states without the laws, indicating that the alternative treatment may be safer for patients suffering from chronic pain related to cancer and other conditions.
Approximately 60% of all deaths resulting from opioid analgesic overdoses occur in patients who have legitimate prescriptions. In addition, the proportion of patients in the United States who are prescribed opioids for non-cancer pain has almost doubled in the past decade, indicating the need to do a more focused examination on the safety and efficacy of these and other treatment options. In states allowing the use of medical cannabis, the drugs may be prescribed as an alternative to opioids.
While noting that evidence for the pain-relieving properties of cannabis is limited, some studies have suggested cannabis may provide pain relief for some patients, said lead author Marcus A. Bachhuber, MD, Robert Wood Johnson Foundation Clinical Scholar at Penn and the Philadelphia VA Medical Center. “In addition, people already taking opioids for pain may supplement with medical marijuana and be able to lower their painkiller dose, thus lowering their risk of overdose.”
Additional results of the study show that the relationship between lower opioid overdose deaths and medical marijuana laws strengthened over time; deaths were nearly 20% lower in the first year after a state’s law was implemented, and 33.7% lower 5 years after implementation.
Although safer treatment of chronic pain may help to explain lower rates of overdose deaths, medical marijuana laws may also change the way people misuse or abuse opioid painkillers, as marijuana and opioids stimulate similar areas in the brain’s pathways. The authors suggest that as more states implement medical marijuana laws, future studies should examine the association between such laws and opioid overdoses to confirm their findings.