Pubdate: Thu, 07 Jul 2016
Source: Boston Globe (MA)
Copyright: 2016 Globe Newspaper Company
Author: Kay Lazar


The arrival of medical marijuana in Massachusetts and other states is 
changing the way doctors prescribe conventional medications, a study 
published Wednesday reports.

The study, one of the first to investigate whether medical marijuana 
laws alter prescribing patterns, analyzed data from 17 states and 
Washington, D.C. It found that after medical marijuana laws were 
adopted, doctors wrote fewer prescriptions for Medicare patients 
diagnosed with anxiety, pain, nausea, depression, and other 
conditions thought to respond to marijuana treatment.

That translated to about $165 million less spent on prescription 
drugs in just one year in the Medicare program, which provides health 
insurance for older adults, according to the study published in the 
journal Health Affairs.

Analysts said the findings are especially significant coming amid the 
nation's opioid crisis and campaigns to reduce the prescribing of 
potentially addictive painkillers.

Researchers not involved in the study described the findings as 
important and provocative, but said more scrutiny is needed to 
definitively say whether marijuana laws are influencing physicians' 
prescribing practices.

W. David Bradford, a health economist at the University of Georgia 
and the study's senior researcher, said an ongoing review of the 
government's Medicaid database, which includes a younger population 
more likely to use marijuana, suggests an even stronger correlation 
between prescribing trends and medical marijuana laws. Medicaid 
insures mostly younger patients who are poor and disabled.

"This research says there is evidence that physicians are responding 
as if marijuana is medicine, and as if there is clinical benefit," 
Bradford said.

The researchers analyzed millions of drugs prescribed by physicians 
from 2010 through 2013 in the Medicare Part D database. They focused 
their analysis on drugs that treat conditions for which marijuana 
might be an alternative treatment, including anxiety, depression, 
glaucoma, nausea, pain, psychosis, seizures, sleep disorders, and a 
muscle control disorder known as spasticity.

They found that for all conditions, except glaucoma and spasticity, 
fewer prescriptions were written when a medical marijuana law was in effect.

To confirm the link to marijuana laws, and not other factors, the 
researchers compared results from the states with medical marijuana 
to states that had not legalized it. They did not see a similar 
decline in prescribing in states without marijuana laws.

As a further test, the researchers selected four drugs prescribed for 
conditions for which there are no studies suggesting benefit from 
marijuana treatment. Those drugs included blood-thinners, 
antibiotics, antivirals to treat the flu, and a drug used in 
dialysis. They found no decline in prescriptions for these drugs.

A medical marijuana law went into effect in Massachusetts in January 
2013, and researchers found that Medicare spending on the drugs 
included in the study declined about $13.9 million for that year in 

Dr. Timothy Naimi, a physician and researcher at Boston Medical 
Center who specializes in substance abuse policy but was not involved 
in the marijuana study, described the findings as "very interesting 
and provocative." But he said it is unclear whether the drop in 
prescriptions was linked to the availability of marijuana for medical use.

"What would be helpful to know would be what proportion of Medicare 
beneficiaries in these states are actually using medical marijuana, 
because that would help to determine whether reductions in 
prescribing are actually due to marijuana laws, or to other factors," 
Naimi said.

But that type of comparison is difficult to make because there are 
not government databases tracking medical marijuana use in the same 
way conventional drug prescriptions are followed.

Avi Dor, a health economist and professor of health policy and 
management at George Washington University's Milken Institute, called 
the study "impressive and timely," given concerns about prescription 
opioid abuse. Opioids are often prescribed for many of the conditions 
the researchers studied.

"We can't be sure about the causality [in the study], but the 
evidence is strong in favor of the marijuana laws leading to the 
substitution away from certain drugs," said Dor, who was not involved 
in the research.

"We just don't know if, over time, the effects they find will wash 
out or become amplified," Dor said. "Physicians and their patients 
are only beginning to experiment with the new therapeutic alternative 
of medical marijuana."

The Health Affairs study estimated that if medical marijuana had been 
available in all states in 2013, the Medicare prescription program 
would have saved about $468 million because of fewer prescriptions 
for just that year - an amount equal to one-half of 1 percent of 
Medicare prescription spending that year.

But the researchers acknowledged that savings for Medicare might 
translate into more costs for patients who pay for medical marijuana 
out of their own pockets, because insurance doesn't cover the drug.

Dr. Kevin Hill, an assistant professor of psychiatry at McLean 
Hospital and Harvard Medical School who studies marijuana, said the 
Medicare savings are important. But he noted physicians remain 
reluctant to recommend marijuana to their patients because they feel 
the evidence supporting its use is insufficient, or they are 
concerned about legal ramifications if they suggest a drug the 
federal government classifies as dangerous.

"Medical marijuana may reduce prescription costs in some cases, but 
there is a risk that medical marijuana may be used for conditions 
that are not supported by evidence," Hill said.
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MAP posted-by: Jay Bergstrom