Consistency in the safety labeling of bioequivalent medications
Article first published online: 8 OCT 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Pharmacoepidemiology and Drug Safety
Volume 22, Issue 3, pages 294–301, March 2013
How to Cite
Duke, J., Friedlin, J. and Li, X. (2013), Consistency in the safety labeling of bioequivalent medications. Pharmacoepidem. Drug Safe., 22: 294–301. doi: 10.1002/pds.3351
- Issue published online: 1 MAR 2013
- Article first published online: 8 OCT 2012
- Manuscript Accepted: 31 AUG 2012
- Manuscript Revised: 22 AUG 2012
- Manuscript Received: 23 JAN 2012
- Regenstrief Institute. Dr. Duke is also supported by a Young Investigator's award from the Indiana Clinical Translational Sciences Institute. Grant Number: KL2RR025760
- drug labeling;
- generic medications;
- adverse reactions;
- drug safety;
Bioequivalent medications are required by the Food and Drug Administration to have identical warnings on their labels. This requirement has both clinical and legal importance, yet has never been validated. We sought to determine the real-world consistency of electronic labeling for bioequivalent drugs from different manufacturers.
Using natural language processing, we indexed the adverse drug reactions (ADRs) found in the Adverse Reactions and Post-Marketing sections of 9105 structured product labels. We calculated the standard deviation in ADR labeling for each bioequivalent drug and the percent deviation of each generic label from its corresponding brand. We also analyzed the performance of individual generic manufacturers. For the 25 drugs with the greatest discrepancy in labeled ADRs, we performed manual review to identify causes of inconsistency.
68% of multi-manufacturer drugs had discrepancies in ADR labeling. For a given drug, the mean deviation in number of labeled ADRs was 4.4, and the median was 0.8 (IQR 0 to 3.2). The mean range in number of labeled ADRs was 12 +/− 0.9, and the median was 2 (IQR 0 to 9). Overall, 77.9% of generic manufacturers produced labels differing from brand. Causes of inconsistency included missing tables, outdated post-marketing reports, and formatting issues.
Despite FDA mandate, bioequivalent drugs often differ in their safety labeling. Physicians should be aware of such differences and regulators should consider new strategies for harmonizing bioequivalent labels. Copyright © 2012 John Wiley & Sons, Ltd.