Adequacy of FDA's prescription to over-the-counter switch criteria in physician evaluation of proposed switches of drug products

Futurists have forecast that, by the turn of the century, a majority of today's prescription drugs will be switched to over-the-counter (OTC) status. Currently, the Food and Drug Administration (FDA) evaluates potential switch candidates primarily using safety, effectiveness, and labeling criteria. These criteria may not be adequate because of the reported mishaps associated with OTC drug use. The criteria implicitly assume that consumers understand and follow labeled directions. They also do not take into consideration whether or not the switched drug product will be beneficial to consumers or is really needed in the market. Need for verbal counseling and market need for the product are two additional criteria that may be necessary for evaluating potential switch candidates. Since switch evaluation committees are comprised mainly of physicians, this project surveyed a nationwide sample of primary care and internal medicine physicians to assess on a drug-specific basis whether or not the existing FDA criteria are sufficient to evaluate potential switch candidates, and whether the two proposed criteria contribute to physicians' switch decision making process. A total of 197 physicians participated in the study. Promethazine, ranitidine, naproxen, and terfenadine, often mentioned in the trade press as potential switch candidates, were selected as the study drugs. Overall, of the four study drugs, physicians favored switching only terfenadine to OTC status; ranitidine received the lowest approval rating. For all four drugs, safety was an important factor in physician switch decisions. Market need was very important in the case of ranitidine and terfenadine switch decisions. Physicians perceived a high need for verbal counseling of all users of ranitidine, naproxen, and terfenadine. Labeling was not a determinant criterion as far as switch decisions were concerned even though it was significantly correlated with switch decisions. The two proposed criteria, market need and need for verbal counseling of all users, greatly improved the predictability of physicians' switch decisions.