Impact of FDA Actions, DTCA, and Public Information on the Market for Pain Medication

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most important classes of prescription drugs used by primary care physicians to manage pain. The NSAID class of products has a somewhat controversial history, around which a complex regulatory and informational environment has developed. This history includes a boxed warning mandated by the Food and Drug Administration (FDA) for all NSAIDs in 2005. We investigate the impact that various information shocks have had on the use of prescription medications for pain in primary care in the USA. We accomplish this by extracting data on nearly 600,000 patients from a unique nationwide electronic medical record database and estimate the probability of any active prescription for the four types of pain medications as a function of FDA actions, advertising, media coverage, and patient characteristics. We find that even after accounting for multiple sources of information, the FDA label changes and boxed warnings had a significant effect on pain medication prescribing. The boxed warning did not have the same impact on the use of all NSAID inhibitors. We find that the boxed warning reduced the use of NSAID COX-2 inhibitor use, which was the focus of much of the press attention. In contrast, however, the warning actually increased the use of non-COX-2 NSAID inhibitors. Thus, the efficacy of the FDA's black box warning is clearly mixed.