What is prescription labeling communicating to doctors about hepatotoxic drugs? A study of FDA approved product labeling.

Purpose The objective of this study was to evaluate the informativeness and consistency of product labeling of hepatotoxic drugs marketed in the United States. Methods We searched the Physicians' Desk Reference—2000 for prescription drugs with hepatic failure and/or hepatic necrosis listed in the labeling. We used a six-item checklist to evaluate the ‘informativeness’ and consistency of the labeling content. An informativeness score equaled the proportion of checklist items present in each drug's labeling. Results Ninety-five prescription drugs were included in the study. Eleven (12%) of the drugs had information related to hepatic failure in a Black Boxed Warning, 52 (54%) in the Warnings section and 32 (34%) in the Adverse Reactions section of the label. The mean informativeness score was 35%; the score was significantly higher, 61%, when the risk was perceived to be high. The informativeness of labeling was not affected by the time of the labeling, but differed across the Center for Drug Evaluation and Research (CDER) Review Division responsible for the labeling. Conclusions The information provided in labeling is variable and affected by many factors, including the perceived level of risk and review division strategy. Product labeling may benefit from current FDA initiatives to improve the consistency of risk-related labeling. Published in 2003 by John Wiley & Sons, Ltd.