Usefulness of treatment with yokukansan, a traditional Japanese medicine, in patients with dementia with Lewy bodies: Retrospective observational study for efficacy and safety of long-term treatment

Kazunori Okahara¹⁾, Yasushi Ishida²⁾, Yoshihito Hayashi²⁾, Toshinori Tsuchiya¹⁾

¹⁾Keimei Memorial Hospital
²⁾Division of Psychiatry, Department of Clinical Neuroscience, Faculty of Medicine, University of Miyazaki

We conducted a hospital-based retrospective observational study in 135 patients with dementia with Lewy bodies (DLB) to investigate the influences of long-term treatment of yokukansan (YKS) on behavioral and psychological symptoms of dementia (BPSD). An obvious improvement of visual hallicinations which were often seen in DLB patients was observed after YKS treatment, and NPI total score and Zarit burden interview score decreased significantly by week 26. No decrease in MMSE score were seen by week 78. An incidence of adverse drug reactions was 1.5%. About 20% of the patients were estimated to have more than one serum potassium lowering event or mild edema, therefore, the necessity of periodic examinations for serum potassium during YKS treatment was suggested. As a long-term treatment with YKS on BPSD in DLB patients was effective and well-tolerated, we concluded that YKS is very useful in the clinical practice.

Key words:dementia with Lewy bodies (DLB), behavioral and psychological symptoms of dementia (BPSD), Neuropsychiatric Inventory (NPI), yokukansan, traditional Japanese medicine (kampo medicine)

Address Correspondience to Dr. Kazunori Okahara, Keimei Memorial Hospital (762 Iwachino, Kunitomi-cho, Higashimorokata, Miyazaki 880-1111, Japan)