From April 2012, Japanese Adverse Drug Event Report database (JADER) has become downloadable for utilization in the public, under the specified acceptable use policy. Given the situation, we focused on the severe eruptions which cases are increased in the public Relief System for Sufferers from Adverse Drug Reactions, for the purpose to analyze the characteristics of typical severe eruptions and a trend or a commonality in the corresponding reported drugs, by utilizing JADER. Disproportionate reporting obtained with ROR (Reporting Odds Ratio) and distribution parameter estimations obtained with Weibull distribution fit for the onset time of drug adverse reactions, were applied for the analysis in addition to the summary of frequency. We obtained 10,171 cases of severe eruptions from JADER, after exclusion of duplicated reports. In the Drug Induced Hypersensitivity Syndrome (DIHS), which has characteristics in clinical time course and causal drugs, we confirmed that typical causal drugs such as anti-epilepsy are frequently reported in JADER. On the other hand, drugs other than typical causal drugs also showed high ROR signal values. In the estimation of Weibull distribution shape parameter fit for drug adverse reaction onset time, DIHS gave estimation apparently different from other severe eruptions. Coincide with the estimation, histogram of onset time for DIHS showed the peak at around 20 days after drug administration, which is later than other severe eruptions. We conclude that analytical approach to obtaining information from multiple aspects of JADER data should be a useful effort for the persons who are engaged in preventive action for drug adverse reactions.

Objective : The incidence rate is used frequently in drug safety assessment. The incidence rate of adverse events is defined as the number of patients experiencing a certain adverse event divided by the number of patients administered a drug in spite of duration of administration (observation). In post-marketing surveillance, the duration of administration (observation) typically differs by patient and most of the analyses fail to take into account the differences in duration of administration (observation). Therefore, we investigated the usefulness of hazard functions in a drug safety assessment using the interim results from Clinical Experience Investigation of the oral anticancer drug, TS-1.
Methods : About three thousand patients with gastric cancer were enrolled in this Clinical Experience Investigation. TS-1 was administrated orally twice daily. One course consisted of consecutive administration for 28 days and 14 days rest. Administration was repeated in two courses. Hematological measurements, stomatitis, anorexia, nausea/vomiting, diarrhea, malaise were analyzed. Adverse events were evaluated in accordance with the criteria of the Japan Society for Cancer Therapy, which were established based on criteria established by the WHO. Time to occurrence of an adverse event was calculated from the first day of administration until the adverse event was first observed. Hazard functions were estimated by smoothing methods using kernel functions.
Results : The occurrence of adverse events using smoothed hazard functions had one peak around 10 days in the first course and decreased by administration rest. With the resumption of administration, the occurrence increased again. The occurrence in the second course were less than that of the first course.
Conclusion : The occurrence peaks of adverse events were estimated graphically by smoothed hazard functions. We conclude that hazard functions are useful as an analytical tool in drug safety assessment.