Effect of Yokukansan for the Treatment of Idiopathic Rapid Eye Movement Sleep Behavior Disorder: A Retrospective Analysis of Consecutive Patients

Kentaro Matsui; Taeko Sasai-Sakuma; Jun Ishigooka; Katsuji Nishimura; Yuichi Inoue

doi:10.5664/jcsm.7816

Effect of Yokukansan for the Treatment of Idiopathic Rapid Eye Movement Sleep Behavior Disorder: A Retrospective Analysis of Consecutive Patients

J Clin Sleep Med. 2019 Aug 15;15(8):1173-1178. doi: 10.5664/jcsm.7816.

Authors

Kentaro Matsui¹, Taeko Sasai-Sakuma², Jun Ishigooka³, Katsuji Nishimura⁴, Yuichi Inoue⁵

Affiliations

¹ Department of Psychiatry, Tokyo Women's Medical University, Tokyo, Japan; Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan.
² Department of Somnology, Tokyo Medical University, Tokyo, Japan; Department of Life Sciences and Bio-informatics, Division of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University.
³ Institute of CNS Pharmacology, Kanagawa, Japan.
⁴ Department of Psychiatry, Tokyo Women's Medical University, Tokyo, Japan.
⁵ Department of Somnology, Tokyo Medical University, Tokyo, Japan; Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan.

Abstract

Study objectives: The herbal medicine Yokukansan (YKS; Yi-Gan San in Chinese) is reported to be effective for treating rapid eye movement sleep behavior disorder (RBD). However, the effectiveness and safety of YKS treatment have not been confirmed in a large sample. Thus, we retrospectively analyzed the outcomes of YKS treatment on patients with RBD using clinical records.

Methods: Treatment outcomes were evaluated using the Clinical Global Impression of Illness Severity (CGI-S) and Improvement (CGI-I) scales. Patients with scores of 1 (very much improved) and 2 (much improved) on the CGI-I were classified as responders. After excluding patients with very mild RBD symptoms and those without detailed clinical information, 36 patients with idiopathic RBD including 17 receiving YKS monotherapy and 19 receiving YKS add-on therapy in addition to other medication were analyzed.

Results: The patients' mean age [standard deviation, SD] was 69.3 [6.8] years, and the mean duration of RBD morbidity [SD] was 5.7 [3.5] years at the start of YKS treatment. Importantly, 12 of 17 patients (70.6%) receiving YKS monotherapy were responders. However, among patients receiving YKS add-on therapy, the proportion of responders was substantially lower (4 of 19 patients; 21.1%). No adverse events were reported, other than mild gastric distress in one case.

Conclusions: Considering the effectiveness of YKS and the low likelihood of adverse events, YKS should be considered as a potential treatment for patients with RBD.

Citation: Matsui K, Sasai-Sakuma T, Ishigooka J, Nishimura K, Inoue Y. Effect of yokukansan for the treatment of idiopathic rapid eye movement sleep behavior disorder: a retrospective analysis of consecutive patients. J Clin Sleep Med. 2019;15(8):1173-1178.

Keywords: Yokukansan; clonazepam; parasomnia; pramipexole; rapid eye movement sleep behavior disorder; treatment.

MeSH terms

Aged
Aged, 80 and over
Drugs, Chinese Herbal / adverse effects
Drugs, Chinese Herbal / therapeutic use*
Female
Humans
Male
Middle Aged
REM Sleep Behavior Disorder / drug therapy*
Retrospective Studies
Treatment Outcome

Substances

Drugs, Chinese Herbal
Yi-Gan San