• by Aaron Baar , April 1, 2008

While the damage may already have been done for the cholesterol-lowering drugs Zetia and Vytorin earlier this year, continued questions about their efficacy raise a point about the role marketing --particularly direct-to-consumer advertising--plays in prescribing medications in the United States.

Results of a study presented at an American College of Cardiology conference in Chicago on Sunday reaffirmed what had already been reported in January: that Vytorin and Zetia are no more effective than better-known and older medications called statins (a category that includes drugs such as Lipitor and Zocor) at reducing LDL (or "bad" cholesterol). The study, as well as an editorial in the New England Journal of Medicine, said that Vytorin and Zetia should only be used after other options--including statins--proved ineffective for patients.

Merck and Schering-Plough, which market Vytorin and Zetia, had already pulled advertising for these products in January after preliminary results of the study were revealed. Combined sales of the two drugs are about $5 billion globally, according to published reports.

A concurrent study in the New England Journal of Medicine also raised questions about the medical community's willingness to prescribe heavily marketed medications over others that had been proven to work, but have lesser marketing support.

According to the study, which looked at the use of Vytorin and Zetia's use in the U.S. and Canada, sales of the two drugs were four times higher in the United States than they were in Canada. One factor in the disparity, according to the study's authors, was direct-to-consumer advertising, which was widely used in the U.S., but is outlawed in Canada.

"In the United States, in 2007, more than $200 million was spent on direct-to-consumer advertising for Vytorin alone, which probably had an effect on U.S. sales," wrote the study's authors. (They also noted that prescription access and availability differences in the two countries may also have played a role.)

"[Advertising] likely played a role," Cynthia Jackevicius, one of the authors of the study, tells Marketing Daily. "Not only does [that advertising] get to consumers, prescribers will see those ads as well."

The study may lend more support to an argument that DTC advertising should be curtailed for a period of time after a drug's approval to make sure of its effect on a larger sampling of patients, Jackevicius says. "It has been suggested in the first two years [after a drug's approval], you may need to exercise a little more caution," she says. "I think some of those suggestions could come up again."

Representatives from Merck and Schering-Plough did not return calls by press time.