Clinical efficacy of Kampo medicine (Japanese traditional herbal medicine) in the treatment of primary dysmenorrhea

Objective: We intended to evaluate the clinical efficacy of Kampo medicine, a Japanese traditional herbal medicine, for primary dysmenorrhea which was prescribed according to the Kampo diagnosis, with classification of its severity. Method: A retrospective evaluation of Kampo treatment in 176 subjects with dysmenorrhea during the previous 12 years was performed. In order to minimize the subjective discretion of the severity of symptoms, classification of the severity level of abdominal pain during menstruation was applied by considering the requirement for non-steroidal anti-inflammatory drugs (NSAIDs) and disturbance of daily activities. The following severity levels were used: no abdominal pain (level 0), abdominal pain with no requirement of NSAIDs (level 1), abdominal pain with no daily activity disturbances with use of NSAIDs (level 2), and painful menstruation which required absenteeism even with use of NSAIDs (level 3). Results: Severity levels before and after Kampo treatment were defined in 108 subjects. Distribution of the severity levels in 108 subjects was significantly changed by Kampo treatment; the numbers of cases in levels 0, 1, 2, and 3 changed from 0 (0%), 0 (0%), 47 (43.5%), and 61 (56.5%) to 5 (4.6%), 42 (38.9%), 51 (47.2%), and 10 (9.3%), respectively. (P < 0.0001) There were 25 kinds of Kampo formulae prescribed in effective cases. Conclusion: Kampo medicine prescribed according to Kampo diagnosis reduced the severity of primary dysmenorrhea and is therefore suggested to be beneficial in improving quality of life.