Research suggests the legalization of medical marijuana in some U.S. states may be reducing the use of prescription drugs.
As of last month, a total of 25 states and Washington, D.C., have legalized marijuana to treat certain health problems, such as neuropathic pain and spasticity, though doctors in these states can only recommend its use, not prescribe it.
In the remaining states, marijuana is classed as a "Schedule 1" drug under the Controlled Substances Act. This means the federal government consider the drug to have high abuse potential, no medical benefits, and major safety concerns.
The United States Food and Drug Administration (FDA) have not approved marijuana for health problems, based on lack of scientific evidence that it is safe and effective. States that have legalized the drug for such use have done so based on decisions by voters and legislators.
The legalization of medical marijuana in many U.S. states has received mixed reactions; some individuals believe it will increase use of the drug for recreational purposes, while others view marijuana as a valuable tool for treating an array of illnesses and believe its legalization will benefit the health system.
According to study co-author W. David Bradford, of the University of Georgia, nobody has really attempted to assess both sides of the medical marijuana argument since California became the first U.S. state to legalize its use back in 1996.
With this in mind, Bradford and colleagues set out to determine how legalization of medical marijuana has affected prescription drug use, which serves as an indicator of whether people really are using the drug for medical purposes.
Medical marijuana being adopted as an alternative treatment
To reach their findings, the team analyzed information on prescriptions filled by Medicare Part D enrollees between 2010-2013.
The researchers looked at what medical conditions the prescriptions were filled for and pinpointed those for which marijuana could be considered an alternative treatment. These conditions included depression, anxiety, nausea, pain, and glaucoma.
Up to 2013, 17 U.S. states and Washington, D.C., has legalized medical marijuana.
The results of the analysis revealed that the overall use of prescription medication fell during the 3-year period. For example, daily doses of prescription drugs for pain and depression fell by 1,826 and 265, respectively.
These findings indicate that many people are turning to medical marijuana as an alternative treatment.
The researchers estimated that in 2013, this reduced prescription drug use led to a total savings of $165.2 million. What is more, they estimated that if all U.S. states had legalized medical marijuana in 2013, this could have led to a saving of around $468 million.
Legalized marijuana may be encouraging patients to seek treatment
The team also found evidence that, in some cases, legalization of medical marijuana in the U.S. may be encouraging more people to seek treatment.
For example, when the researchers assessed prescription drug use for glaucoma - a condition caused by a buildup of eye pressure - they found it had increased by around 35 daily doses between 2010-2013.
The authors note that marijuana can reduce eye pressure by around 25 percent, though only for about an hour. Because recommending marijuana use every hour is impractical, the researchers expected to see a rise in prescription drug use for the condition.
"It turns out that glaucoma is one of the most Googled searches linked to marijuana, right after pain," says Bradford. "Glaucoma is an extremely serious condition that can lead quickly to blindness. The patient then goes into the doctor, the doctor diagnoses the patient with glaucoma, and no doctor is going to let the patient walk out without being treated."
Overall, the researchers say their findings indicate that in U.S. states where medical marijuana is legal, people really are using it to treat their ailments, rather than just for recreation.
However, Bradford still has some concerns about the legalization of medical marijuana, particularly when it comes to how patients obtain the drug.
"Doctors can recommend marijuana and in some states can sign a form to help you get a card, but at that point you go out of the medical system and into the dispensaries," he says.
"What does this mean? Do you then go less frequently to the doctor and maybe your non-symptomatic hypertension, elevated blood sugar and elevated cholesterol go unmanaged? If that's the case, that could be a negative consequence to this."
He and his colleagues plan to adress this question in future research.