CHICAGO – A wave of new television advertisements for some of the nation’s most expensive drugs has insurers and economists bracing for their effect on health-care costs.

In particular, the ads could affect Medicare, which will begin covering some of these expensive treatments over the next two years as a broader prescription benefit for the elderly is rolled out.

The companies are ramping up advertising for treatments for anemia, cancer and rheumatoid arthritis that can cost several hundred dollars for one injection or more than $10,000 for a year.

Critics say there is little reason to advertise such treatments on television because they come under a doctor’s area of expertise. Specialists know what the latest treatments are, critics of the ads say.

“Why on earth would you have to do direct-to-consumer advertising on a drug that costs between $10,000 or $20,000 a year?” asked Dr. Allan Korn, chief medical officer of the Chicago-based Blue Cross and Blue Shield Association, a trade group representing some of the nation’s largest health plans.

“If a consumer could self-treat, they want certain information about options but they are not going to be self-treating with these really expensive drugs,” Korn said. “For nondiscretionary kinds of things, these ads make no sense.”

But drugmakers say TV ads for specialized treatments encourage patients who might not be on medication to see their doctor. The medicines also can prevent more expensive hospitalizations or surgeries, drugmakers say.

Johnson & Johnson, known for its consumer marketing prowess, blazed a trail in 1998 with its TV ads for Procrit, an anemia drug that can cost about $10,000 a year.

In the last year, its new ads have touted Procrit as an energy boost for cancer patients who are asked to see their doctors if they are feeling fatigued. The drug helps produce red blood cells.

For the campaign, J&J last year increased TV ad spending on Procrit by nearly 10 percent, to $56 million, from 2002 levels, according to TNS Media Intelligence/CMR of New York.

“We have data that show 70 percent of chemotherapy patients suffer from chemotherapy-related anemia and all of the fatigue associated with that,” said J&J spokesman John Kouten.

But health plans say the ads pressure doctors to prescribe something that may not be necessary. And there are other fatigue treatments.

“To say you need to take this drug because you are feeling tired or run-down isn’t right,” said Korn, an oncologist. “Chemo makes you feel tired or run-down no matter what your hemoglobin level is.”

Spending on direct-to-consumer advertising, which includes mostly television, will triple this year from 1997, to more than $3 billion.

Insurers noticed an increased demand for prescription drugs in early 1998, within months after the Food and Drug Administration’s August 1997 decision to loosen restraints on radio and TV advertisements for prescription drugs.

Those early ads were for routine maintenance drugs to treat allergies, heartburn and high cholesterol, medicines such as Prevacid for heartburn, Zoloft for depression or Lipitor for high cholesterol that cost a few dollars a pill.

As TV ad spending increased, prescription spending, which had risen about 11 percent annually in the mid-1990s, rose to 18.4 percent in 1999. It has hovered in the mid-to-high teens since, according to most industry estimates.