Objective: The present study aimed to investigate the identification codes of tablets used in clinical practice, and to clarify the influence of these codes on the differentiation of drugs brought in by patients, and those that have been dispensed as one-dose packages at Tottori University Hospital.
Methods: We obtained the identification codes of tablets, which were released on the market before December 2013, based on their package inserts.  Concerning drugs without identification codes, we conducted a questionnaire survey involving companies releasing these drugs in order to clarify the reasons for the absence of these codes.  Among the drugs brought to the Hospital by patients who were hospitalized in 2013, we investigated the identification codes of tablets dispensed as one-dose packages, and the accuracy of the differentiation of these tablets.
Results: We investigated a total of 5,797 tablets. Among the tablets in which the identification codes imprinted on one side of these tablets were the same, the other side did not have codes for 65 tablets (28 pairs), and had different codes for 1,836 tablets (198 pairs).  A total of 244 tablets did not have identification codes.  The most common reason for releasing drugs without such codes was the cost.  Investigation of the drugs brought in by patients hospitalized revealed that some pharmacists mistook Grinolart®50 mg for Glucobay®50 mg due to them having the same code.
Conclusion: To prevent the misidentification of drugs brought in by patients, hospital pharmacists need to cooperate with other hospitals and health insurance pharmacies, and dispense drugs while regarding their distinguishability as of major importance.  In addition, to increase the distinguishability, identification codes need to be imprinted on both sides of tablets, and there is a need to avoid manufacturing drugs whose identification codes are the same.