Wholesale prices for the brand-name prescription drugs widely used by older Americans rose at more than twice the rate of inflation during the year that ended March 31, the AARP says.

The price charged by manufacturers climbed 6.6 percent for a sample of 195 drugs. That's down from the 7.1 percent increase in the year that ended Dec. 31 but still well ahead of the 3 percent general inflation rate, the organization said in a report for release Tuesday.

"We are very disappointed that brand name manufacturers have failed to keep their price increases in line with inflation and we will continue to educate our members and the public about how best to find the most affordable prescription drugs to suit their needs," AARP chief executive William Novelli said.

The Pharmaceutical Research and Manufacturers of America accused AARP of using "fuzzy math."

Prescription drug prices have risen less than overall medical costs, the trade group said. And, PhRMA vice president Ken Johnson added, starting next January seniors will get savings on medicines by enrolling in Medicare's new prescription program.

The study by AARP's Public Policy Institute and the University of Minnesota found price increases for 110 brand-name drugs sampled.

For a typical older person taking three prescription drugs daily, the increase for the year ended March 31 translates to an extra $144.15 cost per year, if they use brand name products and the full price increase is passed along to the consumer, according to AARP,

Looking at the first three months of this year, the study found the biggest price increase, 6.1 percent, was for insulin sensitizing drugs for diabetics. Tied for second with 5.9 percent increases were two types of blood pressure drugs, angiotensin II receptor antagonists and calcium channel blockers.

The single largest increase was 9.5 percent for Combivent, an aerosol drug that improves breathing by helping open bronchial tubes.

The researchers also looked at generic prescription drugs. Overall costs were up 0.7 percent in a check of 75 drugs for the year ended March 31. Only three of the drugs had an increase in the first three months of this year, the report said.