Researchers scrutinized ads for four drugs that have made the transition and found only 11 percent of ads mentioned side effects after the drugs became available without a prescription versus 70 percent before.

"In many, many cases information about risks simply disappeared from the ads once the drugs became over-the-counter," said Dr. Jeremy Greene of Johns Hopkins University in Baltimore, who led the work. "A commitment to fair balance in drug promotion is clearly lost when a drug moves from prescription-only to over-the-counter status."

The study, published in the Journal of the American Medical Association, was supported by CVS Caremark. It includes a sample of 133 television and print direct-to-consumer ads for Claritin (generically known as loratidine), Zyrtec (cetirizine), Xenical/Alli (orlistat) and Prilosec (omeprazole).

The U.S. Food and Drug Administration oversees ads for prescription drugs and requires them to present a "fair balance" of both harms and benefits. Ads for OTC drugs, however, are regulated by the Federal Trade Commission, which has no such requirement.

Greene said people wrongly tend to assume that safety is no longer an issue once a drug moves out onto the aisles at drugstores and grocery stores.

Common painkillers such as ibuprofen can cause bleeding ulcers in the stomach, for instance, and the liver toxicity of acetaminophen, another OTC painkiller, is the most common reason people go to the ER for poisoning, according to Greene.

"These happen to be two examples of over-the-counter drugs that are rightly placed in the sphere of self-medication," he said, "yet they certainly demonstrate that just because a drug is over-the-counter it doesn't mean it's without risks."

The results square with findings published last year by researchers at the University of Wisconsin-Madison School of Pharmacy.

In that study, which included three of the drugs that Greene and his colleagues focused on, prescription ads turned out to contain a similar number of risks and benefits. But after the drugs became available over the counter, the pros outnumbered the cons more than five-fold.

"Consumers can go into a gas station or a grocery store and buy these drugs without ever talking to a doctor or a pharmacist," said Adrienne Faerber, who worked on the previous study. "If they have questions or aren't aware of the side effects of these drugs, they won't get the information they need."

Greene's team also found that the drugs' generic names were often left out of OTC ads.

"The generic name is a very powerful tool for the patient as a consumer in that it helps tie together scientific information on the drug from different places," he told Reuters Health. "It's concerning to us that the consumer is left without that information."

Greene said he sees a couple of different solutions to the problem, including having the FDA oversee ads for OTC drugs as well, or having the FTC adhere to the "fair balance" principle.

Either way, he added, "the solution is not simply to pour out more risks on the page - it is to find a way to communicate risks more effectively."

SOURCE: bit.ly/MvXYT6 Journal of the American Medical Association, online September 11, 2012.

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