PORTLAND – A shift away from generic drugs to newer and costlier brand names is helping push up the costs of prescription drugs in Maine, according to a new study.

The study by the Maine Health Information Center looked at 10 large businesses to determine trends between 1999 and 2000. According to the study, the amount spent on medications increased 18 percent even though use of prescriptions increased only 6 percent.

Aside from price inflation, costs were driven up by a preference for heavily advertised brand names such as the cholesterol-reducing drug Lipitor and the arthritis medication Vioxx.

“You hear a lot of anecdotal talk about the role of advertising,” said Jim Harnar, president of the Manchester-based data gathering organization. “Now you can see how that marketing is affecting people in Maine.”

The use of generic drugs declined 1 percent while the use of brand name drugs increased 9 percent in 2000, the study found.

Generic drugs accounted for 28 percent of drug use, but only 9 percent of cost.

The study found that increased pharmacy costs account for 46 percent of the increase in employers’ combined medical and pharmacy claims. Some aggressively marketed products were found to be leading contributors to higher costs.

“It’s just the wholesale use of the latest and greatest drugs,” said Doug Libby, executive director of the Maine Health Management Coalition, which commissioned the study.

Libby stressed that some of these drugs may be more effective, and that increased use can reflect new care guidelines that keep patients healthier, such as those surrounding cholesterol levels.

At the same time, some health plans have made it more difficult for patients to use the newer, more expensive medications, Libby said. In some cases, he said, patients may have to pay out of pocket for them.

The study was done for 10 employers that belong to the Maine Health Management Coalition, a group of 32 businesses and health organizations with more than 90,000 workers.

The employers that took part in the study are: Lucas Tree, Hussey Seating, Hannaford Bros., L.L. Bean, St. Mary’s Regional Medical Center, state of Maine, Maine Municipal Association, University of Maine System, Maine Medical Center and Bowdoin College.