Abstract
BACKGROUND: Japanese traditional (Kampo) medicines are commonly prescribed in clinical practice, with increasing evidence supporting their use during pregnancy. The efficacy and safety of Kampo medicines during pregnancy have increasingly been studied; however, evidence in support of these medicines is inadequate. Thus, we conducted a temporal trend analysis of Kampo medicine prescriptions to determine the Kampo medicines for which further safety evidence is required. METHODS: Administrative data from pregnant Japanese women who visited acute-care diagnosis procedure combination hospitals between January 1, 2014, and December 31, 2023, were used in this study. Therapeutic categories related to the Kyoto Encyclopedia of Genes and Genomes D numbers 5100 and 5200 were defined as target Kampo medicines. Annual prescription trends were calculated as proportions. Temporal trends in the proportion of prescriptions for each Kampo medicine were assessed using the Cochran-Armitage trend test. Statistical significance was set at p < 0.05. RESULTS: Between 2014 and 2023, the proportion of Kampo medicine prescriptions increased significantly from 12.0% to 13.6% (p < 0.001). As of 2023, tokishakuyakusan (2.9%) was the most prescribed medication, followed by kakkonto (2.4%) and daikenchuto (2.0%). From 2014 to 2023, the proportions of tokishakuyakusan (3.3% to 2.9%) and kakkonto (2.4% to 2.4%) prescriptions showed no significant temporal changes (p = 0.07 and 0.36, respectively). In contrast, the proportion of daikenchuto prescriptions increased significantly from 0.8% to 2.0% (p < 0.001). CONCLUSION: The primary prescribed Kampo medicines were those with established safety evidence for use in pregnant women. The proportion of Kampo medicine prescriptions for pregnant women in Japan has increased over time, with tokishakuyakusan being the most prescribed during the study period.