Apparently, there’s a key change in advertising when a prescription drug goes over the counter.

Although a prescription drug’s risk-and-benefit profile doesn’t change in moving to O-T-C status, consumer advertisements for the O-T-Cs contain much less information about the drugs’ potential risks than the ads for when the medicines were prescription-only, a CVS Caremark-sponsored study finds.

Researchers from CVS, Harvard University, and Brigham and Women’s Hospital analyzed all print and broadcast ads for four prescription drugs — loratadine, omeprazole, orlistat and cetirizine — that had extensive direct-to-consumer (DTC) promotion before and after going O-T-C. The ads were reviewed for descriptive characteristics, presentation of health benefits (specific indications and claims of general health improvement) and potential health harms (side effects, contraindications, warnings and precautions).

Ads for the O-T-C versions of the drugs had significantly less information about the risks of the medications, with only 11% of the ads discussing potential risks for the O-T-Cs, compared with 70% of the ads when the drug was prescription only.

The researchers noted that DTC advertising for prescription drugs is regulated by the Food and Drug Administration and requires balanced information about the risks and benefits. But when a prescription drug switches to O-T-C status, oversight of consumer advertising goes to the Federal Trade Commission, which holds drug ads to the same standards of truthfulness and nondeception as any other consumer product.

That practice should be reconsidered, since public safety is at issue.