Objective: Taking the wrong medicine or medication error is a serious concern to patient safety.  The aim of this study was to statistically survey the relation between the placement of drugs on medicine shelf and the occurrence of error in taking a medicine.
Methods: The study comprised 2 groups.  The incident group contained 43 cases that were erroneously taken in the Obihiro Kosei General Hospital.  The control group contained 43 drug pairs matched by the similarity index of the drug names from among the drugs used in the hospital at random.  The similarity index of drug names was based on 10 quantitative indicators.  The distance of medicine shelf arrangement was represented by three variables: the horizontal distance, the vertical distance and the distance of shelf block.  Conditional logistic regression analyses of the occurrence of medication errors were performed by evaluating the three variables of the distance factor and their interaction for error in taking a similar-sounding named drugs.
Results: Conditional logistic regression analysis revealed that the vertical distance (OR: 0.64, 95%CI: 0.42-0.99) and the distance of the shelf block (OR: 0.74, 95%CI: 0.57-0.97) were significant risk-reduction factors of medication errors.  Four variables were extracted as the most suitable logistic regression model in terms of the interaction between them.  As the interaction between 3 variables (the horizontal distance, the vertical distance and the distance of shelf block) was significant (OR: 0.93, 95%CI: 0.86-0.99), they may be considered as synergistic risk-reduction factors.  Moreover, the horizontal distance was found to be a risk-enhancement factor (OR: 1.52, 95%CI: 0.93-2.48).
Discussion: In order to reduce the risk of medication errors due to similar-sounding drug names, placement of drug on the medicine shelf should take into consideration the three coordinates of the distance factor.

Objective: Currently, the creation of a pharmaceutical risk management plan (RMP) for new drug information is obliged to pharmaceutical companies.  The created RMP is published on the Pharmaceuticals and Medical Devices Agency (PMDA) website.  RMP is a useful information source to ensure drug safety by healthcare professionals, including pharmacists.  “Risk minimization activities” of the RMP are especially important elements for healthcare professionals because they describe measures to minimize risk to patients.  We conducted a cross-sectional survey of the description of the contents of “risk minimization activities” in the RMP.
Methods: The RMP of 177 drugs that had been published in February 22, 2016 were investigated.
Results: Total risks enumerated for the study drugs were 1,678.  “Routine risk minimization activities” constituted 92.0% of total risks.  The most listed item on “routine risk minimization activities” was “attention on the product labeling of the drug package insert” (91.3%).  Differences in the expression level on “attention on the product labeling” were observed.  On the other hand, the most listed item of “additional risk minimization activities” was “the creation of documents for healthcare professionals” (38.3%) and “implementation of Early Post-marketing Phase Vigilance” (27.1%).
Conclusion: A clear understanding of RMP by healthcare professionals is important.  In the RMP, “risk minimization activities” (especially “additional risk minimization activities”) are the most important contents for healthcare professionals, because they include information of documents created by the pharmaceutical company for patient safety.  The level of description of the contents of RMP varies between drugs.  It is essential that these descriptions be uniform the expression level to be easily and accurately utilized by healthcare professionals.

Objective: Similarity of drug names is one factor of dispensing incidents.  The aim of this study was to survey the relation between sensual similarities of drug names and the occurrence of taking errors for pharmacists who actually prepare medicine.
Methods: A pair of drugs (15 incident pairs and 104 control pairs) was displayed on a computer screen at random.  The subject’s task was to determine the sensual similarity of them.  Thirteen pharmacists who prepared these pairs and caused their incidents participated in the experiment.
Results: The result showed that the sensual similarity of drug names of incident pairs was found to be highly significant in comparison to one of the control pairs [p=0.026].  However, the similarity in incident pairs is not necessarily high.  It was suggested that the similarity of drug name was not the only factor of taking error.  Multiple linear regression analyses of the sensual similarity in control pairs were performed, in which 10 variables were reported as quantitative indicators of similarity of drug name and were able to be measured on the internet.  The correlation was good [R²=0.828].  However, this regression model was not useful when adjusting to incident pairs.  In incident pairs, the similarity value calculated by the regression model was lower than the measured sensual similarity.
Conclusion: The result suggested that measured sensual similarity includes other risk factors of taking error, such as appearance similarity and/or efficacy similarity and/or short distance arrangement.  It seemed that the pharmacist’s ability complicated the factor of taking error.