By Pat Anson, Editor

Medical marijuana can significantly reduce pain levels in older adults and reduce their need for opioid pain medication, according to a small study of cannabis users. The findings add to growing -- and sometimes conflicting evidence -- that medical marijuana reduces demand for prescription opioids.

To gauge how effective medical marijuana is at managing chronic pain and reducing opioid use, researchers at Northwell Health, a healthcare network based in New York State, surveyed 138 patients who started using medical marijuana in the previous month. The patients have chronic conditions such as osteoarthritis, spinal stenosis, and chronic hip and knee pain.

The 20-question survey focused on how often they used marijuana, in what form they took it, how much it reduced pain and whether they were able to cut back their use of painkillers.

A month after they started using medical marijuana, most patients reported that their average pain score dropped from 9 (on a scale of 0-10) to a more moderate pain level of 5.6.

Nearly two-thirds said they were able to reduce or stop their use of painkillers, with 27% saying they were able to stop completely. Over 90% said they would recommend medical marijuana to others.

"My quality of life has increased considerably since starting medical marijuana," one patient said. "I was on opiates for 15 years."

"It (medical marijuana) is extremely effective and has allowed me to function in my work and life again. It has not completely taken away the pain, but allows me to manage it," another patient said.

About 45% of patients said they ingested marijuana using vaporized oil, 28% used pills and 17% used marijuana-laced oil. Most said they used marijuana daily, with 39% using it more than twice a day.

"What I'm seeing in my practice, and what I'm hearing from other providers who are participating in medical marijuana programs, is that their patients are using less opioids," said Diana Martins-Welch, MD, co-author of the study and a physician in the Division of Geriatric and Palliative Medicine at Northwell Health. "I've even gotten some patients completely off opioids."

Research in Israel also found that cannabis can significantly reduce chronic pain in elderly patients. But the evidence is less certain that it reduces opioid use.   

A recent study of Medicare and Medicaid patients found that prescriptions for morphine, hydrocodone and fentanyl dropped in states with medical marijuana laws, but daily doses for oxycodone increased. A second study found nearly a 6% decline in opioid prescribing to Medicaid patients in states with medical marijuana laws.  Both studies were conducted during a period when nationwide opioid prescribing was in decline.

A recent study by the RAND corporation found little evidence that states with medical marijuana laws experience reductions in the volume of legally prescribed opioids. RAND researchers believe some pain patients may be experimenting with marijuana, but their numbers are not large enough to have a significant impact on prescribing. 

Despite the uncertainty of the evidence, the Illinois Senate recently passed legislation that would expand the state’s medical marijuana program by allowing doctors to prescribe marijuana to any patient who is prescribed opioid medication.  The idea is to get patients off opioids before they become addicted or dependent on the drugs.

"We know that medical cannabis is a safe alternative treatment for the same conditions for which opioids are prescribed," said Sen. Don Harmon, the bills’ sponsor. "This legislation aims to stop dependence before it begins by providing an immediate alternative."

Although 29 states and the District of Columbia have legalized medical marijuana and a handful of states allow its recreational use, marijuana remains illegal under federal law.