Characteristics on Drug Safety Measures in Japan Stratified by System Organ Classes and Therapeutic Categories in Relation to the Approval Date.

Revisions of drug package inserts (PIs) may be made immediately after approval or after considerable clinical experience; however, it is unclear whether there is a relationship between the characteristics of these safety measures and the period since drug approval. Here, we analyzed 209 cases of safety measures (revisions of the PIs) taken in Japan over 5 years (FY2014 to FY2018). The median, minimum, and maximum period from approval date in Japan to PI revision date was 6.29 years (interquartile range 2.68-15.53 years), 0.16 years, and 59.69 years, respectively. The cases were classified into four groups depending on types of adverse reaction and therapeutic category in relation to the national approval date and international birth date, resulting in the grouping together of particular adverse reactions and therapeutic drugs. For example, "Hepatobiliary disorders", "Blood and lymphatic system disorders", "Respiratory, thoracic and mediastinal disorders", "Antineoplastics", "Chemotherapeutics", and "Other agents affecting metabolism" were associated with the group of safety measures taken early after approval of a drug soon after the international birth date, suggesting that careful attention at an earlier stage after approval is necessary for these adverse reactions and drugs. Understanding such features of PI revisions makes pharmacovigilance planning more appropriate, contributing to the implementation of rapid and proper safety measures after drug approval.