Many of the brand-name medications most commonly taken by older adults increased in price by almost 10 times the average annual rate of inflation from 2012 to 2017, according to a Senate report released Monday.

Findings contained in “Manufactured Crisis: How Devastating Drug Price Increases are Harming America’s Seniors,” released by Sen. Claire McCaskill (D-MO), the ranking member of the Senate Homeland Security and Governmental Affairs Committee, “underscore the need for further investigation by the committee and other policymakers into dramatic price spikes and their impact on healthcare system costs and financial burdens for the growing U.S. senior population,” the report concludes.

“Can you imagine if you went to an auto dealership and last year’s exact model was being sold at a 20 percent markup, and then you went back the next year and it had happened again?” said McCaskill, who also is the former ranking member of the Senate Special Committee on Aging and remains a member of that committee. “That’s exactly what’s happening in the prescription drug industry, where the cost of identical drugs skyrockets year after year,” she added.

The report looked at overall price increases among the top 20 most commonly prescribed brand-name drugs for older adults in the Medicare Part D program and found that prices for these medications had increased 12%, on average, every year for the past five years. That’s 10 times more than the average annual rate of inflation, according to the report.

Also, 12 of the drugs had increased in price by more than 50% in those five years, and six of the 20 had price increases of more than 100% during that time. In one case, the weighted average wholesale acquisition cost for a single drug increased by 477%.

Although 48 million fewer prescriptions were written for the top 20 most commonly prescribed brand-name drugs for seniors between 2012 and 2017, total sales revenue resulting from these drugs increased by almost $8.5 billion during the same period, according to the report.

The report cites data from the Centers for Disease Control and Prevention that 91% of adults aged 65 or more years take at least one prescription medication, 67% take at least three, and 41% take five or more. Twenty percent of out-of-pocket healthcare expenses paid for by Medicare beneficiaries (excluding premiums) are for prescription medications, according to the report, citing Centers for Medicare & Medicaid Services cost and use data.