Objective: The Japanese risk management plan (RMP) contains the risk minimization action plans for important potential risks of drugs.  One of the basic risk minimization action plans is reminding on package insert; however, we found that some potential risks were not described in package inserts.  In this study, we investigated the description of potential risks on package inserts.
Design: Document analysis.
Methods: We collected all posted RMP documents and the package inserts of corresponding products from the Pharmaceutical and Medical Devices Agency website on January 31, 2015 and investigated the risk minimization action plans of important potential risk items and whether the items had been described in each package insert.
Results: Of 268 important potential risk items in 81 products, 56 items were not described on package insert.  The major reason for not including the risk items on the package insert was “causality was not indicated sufficiently” and some items had no written reason.
Conclusion: About 20% of important potential risks are not described in package inserts.  Because most post-marketing pharmacovigilance plans depend on spontaneous reporting by healthcare personnel, description on package insert, the most frequently referred drug information resource, should be considered.