Medicaid pharmacy costs for the blood-thinning drug Plavix jumped at around the same time the drug’s maker started advertising it to consumers - even though the number of people prescribed the drug didn’t change, new research shows.

In the current issue of the Archives of Internal Medicine, Dr. Michael R. Law of the University of British Columbia in Vancouver and colleagues note that spending by government insurers for prescription drugs rose about 15 percent each year between 1994 and 2004. There’s been an assumption that advertising drugs to consumers helps drive up prescription drug costs but there’s little evidence to back this up.

To investigate, Law and his team looked at Medicaid costs for Plavix from 1999 through 2005. The drug’s maker, Bristol Myers Squibb/Sanofi-Aventis, didn’t start advertising the drug to consumers until 2001. Medicaid, which helps pay for health care for low income people, accounts for two-thirds of all government spending on prescription drugs.

Before and after 2001, Law and his team found, the number of Plavix pills dispensed for every 1,000 enrollees in the plans they studied stayed the same. But starting in 2001, Plavix cost 40 cents more per pill, a 12 percent increase that translated to an additional $207 million in Medicaid pharmacy spending.

While the study didn’t look into why the per-pill cost of Plavix rose in 2001 - in the same quarter that the company launched its consumer ad campaign for the medication - “the timing of this increase in price is certainly suspect,” Law told Reuters Health.

In a written response to Reuters Health, a spokesperson for the drug company said: “The Bristol Myers Squibb/Sanofi pharmaceuticals partnership support direct-to-consumer advertising as a way to encourage consumers to play a more active role in their healthcare.”

In previous research, Law noted, he and his colleagues found that advertising drugs to consumers didn’t result in a rise in people taking the medication. “The public should rightly wonder why they’re paying millions in extra drug costs to pay for advertising campaigns that don’t work,” Law said.

A related study in the same issue suggests that another type of campaign could be more effective. Dr. William G. Weppner from the Veterans Affairs Medical Center in Boise, Idaho, and his colleagues found that 30 of the 50 most commonly prescribed medications offered some type of discount or free sample voucher on-line. They also found that a Google search for a drug often steered consumers directly to Web sites making such offers.

Studies suggest doctors’ prescribing habits may be influenced by the availability of free samples, and that physicians may prescribe drugs to patients who request a medication after seeing it advertised even if that patient doesn’t need it, Weppner and his team note. They also found that discount and free sample offers emphasized a drug’s benefits while making information on risks less prominent.

“Through such marketing, patients and consumers may be poorly served by risk information that is not well presented and be misled by a discount whose true value is only a fraction of the true cost for a prescription with no generic alternative,” the researchers say.

“When it comes to prescription drugs, a lot more effort goes into marketing than informing,” Drs. Steven Woloshin and Lisa M. Schwartz of the Veterans Affairs Medical Center in White River Junction, Vermont, note in a commentary accompanying the studies. They call the link between advertising and rising costs found in Law’s study “plausible.”

While the Food and Drug Administration has been criticized for being too cozy with the pharmaceutical industry, Woloshin and Schwartz add, it’s actually “a gold mine” of unbiased information for doctors and patients that should be made more accessible to consumers. “It’s time for the FDA to bring its information to the market,” they conclude.

SOURCE: Archives of Internal Medicine, November 23, 2009.