Wholesale prices for popular brand-name prescription drugs rose an average 7.1% in 2004, more than twice the general inflation rate, a new study commissioned by the nation's largest seniors lobby says.

The increase is the biggest in the five years that AARP, with 35 million members, has sponsored the study. It's just slightly higher than the 7% price rise in 2003. The group, which has pushed for lower drug prices, is set to release its report today.

The findings come from an examination of prices charged by manufacturers on 195 brand-name prescription drugs widely used by Americans 50 and older. The study's authors said such increases are routinely passed on to consumers in retail prices.

Bill Novelli, the group's CEO, called the increases disappointing, particularly in the year after President Bush signed a sweeping overhaul of Medicare. The new law will provide seniors with a prescription-drug benefit next year. But it prohibits the government from negotiating drug prices on behalf of consumers.

Manufacturers “have failed to keep their price increases in line with inflation, despite consumer appeals for them to hold the line,” Novelli said. “Much more needs to be done to slow down spiraling drug pricing.”

Ken Johnson of Pharmaceutical Research and Manufacturers of America, the trade group of brand-name drugmakers, called the study “exaggerated and misleading.” He said the use of wholesale prices excludes factors such as rebates that could cut retail costs.

“Price data clearly shows prescription-drug prices have increased about 4% a year,” Johnson said. He called that in line with growth in other health costs.

AARP supported the 2003 Medicare law, which gave a big political boost to Bush's effort to pass the legislation. But the group also backed giving the federal government the power to negotiate lower drug prices, something Bush opposed and the law prohibited.

This year, AARP is the most powerful opponent of Bush's proposal to establish private investment accounts with Social Security taxes. It has come under attack from groups such as USA Next, which bills itself as “the conservative alternative to AARP” and gets financing from corporations, including drugmakers.

The “Rx Watchdog Report” study was conducted by the AARP Public Policy Institute and the PRIME Institute, an independent research organization at the University of Minnesota's College of Pharmacy.

Compared with 2003 wholesale prices, the average 2004 price increase was 2½ times the general inflation rate of 2.7%, as measured by the federal Consumer Price Index for all urban consumers.

Since the end of 1999, the study says, manufacturers of 153 brand-name drugs measured in each of those years have raised prices an average of 35.1%. Total inflation during that same period was 13.5%.

The study details wholesale price increases for the most popular prescription drugs among seniors in commonly used dosages. Lipitor, used to control cholesterol, jumped 6.4%. Celebrex, for arthritis, rose 6.6%; Norvasc, for high blood pressure, increased 4.2%. The heart disease drug Plavix went up 7.9%.

The AARP study said that wholesale prices for 75 commonly used generic drugs rose 0.5% in 2004.