SIOUX FALLS, S.D. — It seems like a simple problem to solve: More pain requires stronger painkillers.

But new research that looked at opioid painkiller prescriptions given to about 50,000 Veterans Affairs patients shows boosting painkiller doses for some patients didn't do much more to ease pain than those whose doses were kept the same.

Put simply, for opioid painkillers, more is not better. In fact, more can be much, much worse.

The research was recently published in the Jan. 9 issue of the journal Pain by researchers from the Minnesota and Central Arkansas VA systems and three universities, with a companion study that appeared Jan. 16 in the journal Addiction, that showed increased risk of side effects from higher doses.

“What we found in one paper was that the pain relief the provider and the patient are going for really isn’t there when they increase their doses,” said pharmacist Dr. Corey Hayes, co-author of the studies and an assistant professor in the Center of Health Services Research in the College of Medicine Department of Psychiatry at the University of Arkansas for Medical Sciences.

“You don’t see the benefit, but you do see the risk," he said. "Our overall message is, when you’re thinking about increasing the dose, you need to realize the risk it brings, too.”

Researchers compared medical records of 53,187 VA patients prescribed opioids for chronic pain between 2008-2015. Nine in 10 of the veterans studied were male. Seven in 10 were white.

About 32,000 received about their usual average daily dose. About 21,000 patients had their dose increase more than 20%. Researchers compared how those in each group reported their pain. They found that patients who got higher doses did not describe feeling less pain.

While opioids are effective pain relievers, they also have a high risk of abuse and addiction. In the companion research reported in the journal Addiction, researchers concluded boosting the dose of opioid painkillers also boosted the risk for substance abuse and adverse effects such as attempted suicide and accidental falls.

“For people who escalated their dose, compared to people who just maintained their dose, the increase in risk for developing a substance use disorder was about 30% when we look at all substance use disorders,” said pharmacist Dr. Brad Martin, a professor in the UAMS College of Pharmacy’s Division of Pharmaceutical Evaluation and Policy. “Not surprisingly, it was highest for opioid use disorders, which increased about 50%. Use of other drugs and alcohol use disorders went up about 15-20%.”

The new study was funded by the National Institutes of Health. In addition to VA, the authors represent the University of Arkansas for Medical Sciences, University of Minnesota Medical School and the University of Florida.