The drug-drug interaction (DDI) is a phenomenon in which the efficacy of a drug is weakened or enhanced when multiple drugs are combined, the DDI can cause serious health risks to patients. In the clinical setting we are particularly careful when administering drugs with DDI relationships, but Japanese DDI information alone runs the risk of overlooking serious DDIs. Consequently, we believe that the DDI information of each country will be integrated to improve coverage. However, it has been difficult to share and analyze DDI data internationally because each country and region has different codes for identifying drugs. Thus, we aimed to map the Japanese and international drug codes to enable international data sharing.
We established a method to map the YJ code of the Japanese drug code to the RxNorm of the international standard drug terminology (Figure1). This approach has made Japanese drug information readily available to researchers and medical institutions in other countries, forming the basis for facilitating international data sharing. Furthermore, through comparison of the Japanese and international DDI information (Figure2), it became clear that agreement between the DDI severity classifications was uniformly low, indicating that clinically essential data should be added to each DDI information (Figure3). This means there are no clear internationally agreed-upon criteria for setting DDI severity, and we noted that severity information for DDI needs to be coordinated to be consistent.
The results of this study are expected to contribute greatly to the improvement of medical safety and the international integration and standardization of drug information, and to play an important role in refining DDI risk assessment and ensuring consistency of international medical data in the future.