Minnesota lawmakers struck a meticulous balance in 2014 when passing the medical-marijuana law. After hearing from those who believe the plant offers relief traditional drugs do not, legislators combined compassion with common sense. The state now allows marijuana pills or liquid for a narrow group of medical conditions, providing access for those who might benefit while deterring recreational users.

The Legislature also delegated authority to state Health Commissioner Ed Ehlinger to expand the law, and it set a swift deadline for him to do so. Before January, he must decide whether to add a new approved use — “intractable pain” — that could allow thousands of Minnesotans to access medical marijuana for the first time.

Ehlinger should approve the change, and Gov. Mark Dayton should support it. The medical evidence for marijuana’s effectiveness in pain treatment is stronger than it is for some conditions the state has already approved. Research also suggests that providing marijuana as an alternative to prescription pain drugs could significantly reduce overdose deaths from them.

Moreover, the state law has a built-in safeguard to ensure that expanding it in this way would not upset the equilibrium between medical need and necessary safeguards against recreational use.

Stories like little Elisa McCann’s are a powerful reminder of why Minnesota lawmakers allowed access to marijuana, long an illegal drug. Elisa, featured in an Oct. 18 Star Tribune story, is a 2-year-old St. Paul toddler who suffers terribly from a disease that causes her skin to blister easily. But her parents are understandably leery of prescription opioid drugs, whose use carries risks, and want to try medical marijuana as an alternative.

Unfortunately, the pain control needed by Elisa and thousands of other Minnesotans coping with pain from conditions such as neuro­pathy or rheumatoid arthritis doesn’t fit into the law’s current list of nine approved medical conditions: AIDS or HIV, Crohn’s disease, Tourette syndrome, glaucoma, ALS, seizures, muscle spasms, and cancer or a terminal illness that is accompanied by pain or wasting disease.

While medical research on marijuana’s value is far from robust, studies do exist. In June, the prestigious Journal of the American Medical Association (JAMA) published an analysis of studies on 79 medical trials involving 6,462 participants who used cannabinoids (drugs derived from marijuana). The authors’ conclusion: “There was moderate-quality evidence to support the use of cannabinoids for the treatment of chronic pain and spasticity. There was low-quality evidence suggesting that cannabinoids were associated with improvements in nausea and vomiting due to chemotherapy, weight gain in HIV infection, sleep disorders and Tourette syndrome.”

It should be noted that an accompanying JAMA editorial did not endorse medical marijuana’s use, citing among other reasons the dearth of research about the effects of repeated exposure, especially in children, as well as interactions with other drugs.

What Minnesota’s law does is allow a medical professional — doctor, advanced nurse practitioner or physician assistant — to use their best judgment on a case-by-case basis to determine if medical marijuana is an appropriate alternative. Expanding this latitude to help those in pain is a reasonable step.

Like Minnesota, Arizona requires medical approval. But unlike Minnesota, pain treatment is an approved condition, providing a useful comparison in the debate here over expanding the law. Arizona has about 80,000 approved users. Pain is by far the most common reason for its use, said the University of Arizona’s Will Humble, who oversaw the law’s implementation for the state. Humble said the prevalence of young men using the drug to treat pain (a demographic group unlikely to require pain treatment) suggest that recreational users are abusing the law.

But, Humble noted, Arizona’s 2010 voter-approved initiative may have enabled this by allowing “naturopaths,’’ an alternative type of health care provider, to prescribe medical marijuana. “If your statute excludes naturopaths, you’re almost all the way there in terms of implementing it responsibly,” Humble said. Minnesota’s law does not include naturopaths, suggesting that expanding the law here would not lead to widespread recreational use as many in law enforcement fear.

A 2014 research article published in JAMA Internal Medicine also found an unexpected benefit to allowing marijuana as a pain treatment alternative: The “annual number of deaths from prescription drug overdose is 25 percent lower than in states where medical marijuana remains illegal.’’ Opioid addiction is a national health crisis. The Star Tribune Editorial Board shares Humble’s view that medical marijuana for pain could be key in getting a handle on this dangerous epidemic — another reason to expand the law here.