Study touts targeted drug ads

The controversy that brought Vioxx into the national spotlight is dying down, but several Penn professors think there is more to be learned from the incident.

Vioxx, a painkiller, was withdrawn from the market after evidence emerged that the drug caused severe heart problems in a few cases. One of its direct competitors, Celebrex, which works by the same mechanism, remains on the market but carries the Food and Drug Administration's most severe warning, the "black box."

Pharmacology researchers Garret FitzGerald, Tilo Grosser, and Susanne Fries argue in separate articles this month in the journals Gastroenterology and the Journal of Clinical Investigation that marketing to the drug solely to patients at risk for gastrointestinal bleeding would have been appropriate.

Instead, the drugs were promoted and prescribed widely.

Fries found that gearing a drug toward a smaller portion of the population is "surprisingly very easy to do" and thinks it should be used for most drugs during clinical trials. She said the "pharmaceutical industry isn't interested because they cannot sell to a large group" if treatments are targeted toward smaller segments of the market.

This new, more targeted form of medicine is just beginning to emerge as a field, and BiDil a drug targeted specifically toward blacks, just passed FDA scrutiny.

Merck & Co. Inc. which manufactures Vioxx, has come under intense scrutiny from scholars and has been hit with thousands of lawsuits contending that the firm deliberately withheld data on the risks of the drug.

A category of painkillers called COX-2 inhibitors were developed to reduce the risk of gastrointestinal bleeding seen in traditional non-steroidal anti-inflammatory drugs, known as NSAIDs.

The irony, says Grosser, is that heart problems caused by Vioxx are "rare events" and occur at about the "same rate as gastrointestinal side effects in traditional NSAIDs." The researchers believe doctors would see better outcomes if patients at risk for gastrointestinal bleeding took COX-2 inhibitors and patients at risk for heart attack took traditional NSAIDs.

Comparing Vioxx and Celebrex, both COX-2 inhibitors, gave them some idea of just how much an individual's genes and lifestyle can affect treatment. Vioxx is the stronger inhibitor, but many patients taking Celebrex showed even more of an effect than those taking Vioxx.

Since COX-2 inhibition is thought to be responsible for the cardiovascular side effects seen with Vioxx, other drugs may have similar problems in certain segments of the population. Identifying what groups are at risk and what might be causing the variation is a project largely for the future, Grosser said.

Gerontological Nursing professor Sarah Kagan saw the study as "putting forth a more sophisticated argument about what the future should look like."

Kagan said the issue of differences in how people take medicine adds to the variation in individual responses to that medicine. She added that human beings are not "rats in the lab, where ... we know the rats drink 'X' amount" of a drug.

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