After he was diagnosed with diabetes a few years ago, Rob Kilbourn and his doctor settled on a pill that controlled his blood sugar perfectly. Eight months later, his health insurer took it off the list of drugs it pays for, sending him into a weekslong scramble for a substitute that would work as well.

Now he has to inject his meds in addition to taking a pill, and it took several doctor visits and lab tests to find the right combination.

"I went from taking a pill working wonderfully and now I'm injecting myself. It is frustrating that our health care is being determined by insurance companies and not by our doctors," said Kilbourn, of Lakeville.

Nearly a half million Minnesotans have diabetes, and hundreds of them go through this ordeal every year, sometimes more than once, when insurers update their drug formularies. But the problem extends far beyond diabetes, with thousands of Minnesotans battling chronic conditions such as depression, asthma and high blood pressure forced to switch medications.

The changes can mean higher costs for new drugs and more co-payments for office visits to get new prescriptions and lab tests. They also can lead to medical complications as patients transition from one drug to another, doctors say.

"It is always worrisome when you are having to switch someone from a drug that they are on," said Dr. David Thorson, a family practitioner at Entira Family Clinics in White Bear Lake. "Medically you would never do that if you didn't have to."

Medication switches are driven by the same market forces that can cause higher drug prices. Health insurers rely on pharmacy benefit managers (PBMs) to negotiate deals with drug companies, which pay rebates back to the insurers in exchange for higher sales, especially if a drug is selected exclusively among competitors for the formulary.

Recently, U.S. Health and Human Services Secretary Alex Azar, himself a former drug company executive, said that PBMs have an incentive to select higher-priced drugs because they earn higher fees if they select drugs that have higher rebates.

"It is what I call a reverse perverse market," said Stephen Schondelmeyer, a nationally recognized drug market researcher at the University of Minnesota College of Pharmacy. "I would argue it is a deceptive market practice."

The federal government is considering doing away with rebates altogether. Lawmakers in St. Paul are also considering bills that would license PBMs, regulate drug prices, require transparency about prices and rebates and prohibit health plans from changing formularies during the plan year.

For diabetics, it is not just insulins that get switched. Diabetic supplies, like blood testing strips and meters that are used to monitor blood sugar levels, are frequently changed.

Kilbourn was forced to change testing strips three times in one year.

"My insurance is decent, but it is a problem if you are forced to switch and if you have to pay for a new meter or part of a new meter," he said.

Quinn Nystrom, who has type 1 diabetes, recalls being forced to switch drugs and supplies at least seven times over the last several years, including three times for insulin.

Two years ago her health plan wanted her to change to an insulin that she had previously tried but that gave her bad side effects. Under the health plan rules, she could appeal the change but only after trying the insulin that had failed her in the past.

"They make you do this thing called 'fail first.' They make you go on [a different drug] to prove to them that it does not work. To me it is so absurd that that process would be OK," said Nystrom.

With the help of her doctor and many phone calls and faxes to the health plan, Nystrom was able to stay on her insulin. But her victory was short-lived. She still has to grapple with its high price — she recently paid $595 for her monthly supply of two vials of insulin.

"You have to pony up that money or you are going to jeopardize your life," said Nystrom, of Baxter, Minn.

Schondelmeyer, who advises the university's employee drug plan, said the program's insulin spending is eight times higher than 12 years ago.

"Incomes haven't gone up that much. The cost of living hasn't gone up that much," he said. "It is a market run amok."

Altogether, prescription drug spending in Minnesota has increased 7 percent each year between 2012 and 2016, according to a report released last week by the Minnesota Health Department. That's higher than overall health care spending, which grew 4 percent each year.

When diabetics switch insulins, they often have to make more trips to the doctor for blood tests, which are different from the pinprick tests they do at home.

"There are hidden costs that go beyond simply the cost of the medication," said Thorson. "With diabetics, we work hard to get them to a controlled state. You have to be more careful because you don't know if they are going to react badly to that one brand."

Dr. Alexis Vosooney, a family practitioner in West St. Paul, has to cope with formulary changes every January when the plan year starts. But she is also seeing many changes during the middle of the year. Insulin switches are common, but she has also seen it with antidepressants.

"It is really difficult for a patient who has achieved a great place with their mental health to suddenly change their medication," she said. "When people go to the doctor, they trust that the doctor is choosing the right medication for them."

Sometimes the formulary offers a doctor only one choice.

Take the Blue Cross and Blue Shield HMO formulary for people on Medicaid and MinnesotaCare. In 2017, it offered six options for basal insulin, which is taken between meals. In 2018, that dropped to three. This year it is just one.

Eagan-based Blue Cross said that it works with its PBM, Prime Therapeutics, to strive to get safe drugs at the lowest cost.

"To this end, our Blue Plus HMO has focused the brand basal insulin coverage on our Medicaid formulary to the most effective and affordable option available," said a company statement.

As with most formularies, patients can appeal to get the drug that they want.

"A lot of people don't know that they can fight back," said Nystrom, who considers herself a diabetes advocate. "They think that is the final decision."

Sen. Matt Little, DFL-Lakeville, has introduced a bill that would prohibit plans from making switches for diabetes medications during the plan year.

"How people with diabetes are being treated is one of the most egregious areas in terms of what is happening with the broader problem of pharmaceuticals," he said.

Another bill introduced by Sen. Carla Nelson, R-Rochester, would ban midyear formulary changes for all drugs.

"Nobody should be able to change that contract in midstream," said supporter Sen. Mary Kiffmeyer, R-Big Lake. "That is really harmful."

Glenn Howatt • 612-673-7192 Twitter: @GlennHowatt