August 26, 2014
Medical Marijuana Laws May Be Linked To Decrease In Prescription Overdose Deaths
April Flowers for redOrbit.com - Your Universe Online
Despite controversy and federal laws, a few states have made marijuana legal for medical use to manage chronic pain and other conditions. A new study, published in JAMA Internal Medicine, reveals that those states have a 25 percent lower rate of death by prescription drug overdose than in states where marijuana remains illegal.
The research team included scientists from Johns Hopkins Bloomberg School of Public Health, the Philadelphia Veterans Affairs Medical Center, and the Perelman School of Medicine at the University of Pennsylvania. Medical marijuana laws are controversial, and opponents have raised concerns that such laws might promote the use of marijuana among children. The study findings, however, show that these laws have unintended benefits, as well. The researchers acknowledge that more research is needed, but suggest that the broader availability of medical marijuana might help reduce the alarming growth in overdose deaths attributed to prescription pills.
In particular, the study looked at opioid analgesics such as Vicodin, OxyContin and Percocet, which are all prescribed for moderate to severe pain. These drugs work by suppressing a person's perception of pain.
"Prescription drug abuse and deaths due to overdose have emerged as national public health crises," Colleen L. Barry, PhD, an associate professor in the Department of Health Policy and Management at the Bloomberg School, said in a statement. "As our awareness of the addiction and overdose risks associated with use of opioid painkillers such as Oxycontin and Vicodin grows, individuals with chronic pain and their medical providers may be opting to treat pain entirely or in part with medical marijuana, in states where this is legal."
The researchers used Centers for Disease Control and Prevention (CDC) death certificate data, finding that the rate of prescription painkiller overdose deaths increased across all 50 states from 1999 to 2010. The rates of opioid analgesic overdose deaths, however, was approximately 25 percent lower in 13 states with medical marijuana laws active during the study period.
As of June 2014, 23 states and Washington DC have enacted medical marijuana laws. These laws allow patients with chronic or severe pain from conditions such as cancer or multiple sclerosis to use marijuana to relieve their symptoms. Patients with nausea and depressed appetite have also found relief.
"In absolute terms, states with a medical marijuana law had about 1,700 fewer opioid painkiller overdose deaths in 2010 than would be expected based on trends before the laws were passed," said Marcus Bachhuber, MD, of the Philadelphia Veterans Affairs Medical Center and the University of Pennsylvania. The mechanism underlying these results is not yet clear, but Bachhuber says that it might be due to people with chronic pain choosing alternative treatments. Medical marijuana laws could also be causing the decrease in overdose deaths by changing the way people abuse or misuse prescription pain medications.
Most deaths, approximately 60 percent, resulting from opioid analgesic overdoses occur in patients who have legitimate prescriptions. The rate of non-cancer patients who are prescribed opioids for pain has almost doubled in the last ten years. States that allow medical marijuana use also allow doctors to prescribe marijuana instead of such opioids. Trevor Hughes of USA Today reports that more than 15,000 US citizens die annually from prescription painkiller overdose.
"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," Bachhuber said in a separate statement.
The benefits and risks of using medical marijuana to treat pain remain unclear, according to Brendan Saloner, PhD, an assistant professor in the Department of Health Policy and Management at the Bloomberg School. "Given the fast pace of policy change, more research is critical to understand how medical marijuana laws might be influencing both overdose deaths and the health trajectories of individuals suffering from chronic pain," he said.
Other key findings of the study suggest that the relationship between medical marijuana laws and lower overdose rates has strengthened overtime. The first year after the state's law was implemented, deaths decreased by nearly 20 percent, while five years after the rate was 33.7 percent lower. The authors suggest that more states should enact such laws and that more studies are needed to understand the relationship between medical marijuana use and the decrease in opioid overdoses.
In a related commentary, Marie J. Hayes, Ph.D., of the University of Maine, Orno, and Mark S. Brown, M.D., of the Eastern Maine Medical Center, Bangor, write, "If medical marijuana laws afford a protective effect, it is not clear why. If the decline in opioid analgesic-related overdose deaths is explained, as claimed by the authors, by increased access to medical marijuana as an adjuvant medication for patients taking prescription opioids, does this mean that marijuana provides improved pain control that decreases opioid dosing to safer levels?"
Kevin Sabet, director of the Drug Policy Institute at the University of Florida College of Medicine, expressed concern over the method of data collection and analysis in this study. He told Hughes that the study should have differentiated between states with strict and lax medical marijuana laws, as well as examine emergency-room admissions and prescription data. He would also like to have seen them include data on the impact of methadone clinics, finding it hard to believe that there is such a sweeping reduction in predicted deaths.
"In today's supercharged discussions, it could be easily misunderstood by people," he said of the study, which he faulted for drawing distinct conclusions based on limited data. "There may be promise in marijuana-based medications but that's a lot different than 'here's a joint for you to smoke.'"