Effectiveness of Japanese traditional medicine yokukansan for nocturia due to sleep disorders

Aim To evaluate the effectiveness of yokukansan, a traditional Japanese medicine, as treatment for nocturia due to sleep disorders. Methods In this study, we included patients diagnosed with nocturia due to sleep disorders, evaluated using the Pittsburgh Sleep Quality Index (PSQI). Participants received 2.5 g of yokukansan, three times daily, for 12 weeks. We evaluated the changes in the overactive bladder (OAB) symptom score (OABSS), hours of undisturbed sleep (HUS), and PSQI score. In addition, patients were categorized based on the severity of their sleep disorders, and we divided patients into two groups according to whether the severity of the disorder was downgraded after treatment: the improved and unchanged groups. Results Among 35 patients with a mean ± standard deviation age of 73.2 ± 10.5 years, yokukansan administration was associated with significant improvements in nighttime urinary frequency (from 3.8 ± 2.1 to 2.1 ± 1.9), total OABSS score (from 4.9 ± 1.8 to 2.9 ± 1.9), OABSS urgency score (from 1.3 ± 1.0 to 0.7 ± 0.9), HUS (from 2.2 ± 0.6 to 3.5 ± 1.1 h), and global PSQI score (from 11.9 ± 3.1 to 10.0 ± 1.4; all p < 0.001). In addition, significant improvements were noted in both the improved and unchanged groups in terms of the total OABSS, nocturia, and urgency scores. Furthermore, yokukansan treatment was related to improved global PSQI scores in both groups (improved group: from 10.8 ± 0.7 to 8.6 ± 0.5, p = 0.001; unchanged group: from 12.3 ± 3.4 to 10.4 ± 1.3, p = 0.004). Conclusion Yokukansan may effectively ameliorate nocturia due to sleep disorders.