Rikkunshi-to attenuates adverse gastrointestinal symptoms induced by fluvoxamine

Upper gastrointestinal (GI) symptoms such as nausea and vomiting are common adverse events associated with selective serotonin reuptake inhibitors (SSRIs), and may result in discontinuation of drug therapy in patients with depressive disorder. Rikkunshi-to (formulation TJ-43), a traditional herbal medicine, has been reported to improve upper GI symptoms and comorbid depressive symptoms in patients with functional dyspepsia. The aim of the present study was to determine if TJ-43 reduces GI symptoms and potentiates an antidepressant effect in a randomized controlled study of depressed patients treated with fluvoxamine (FLV).

Fifty patients with depressive disorder (19-78 years, mean age 40.2 years) were treated with FLV (n = 25) or FLV in combination with TJ-43 (FLV+TJ-43) (n = 25) for eight weeks. The following parameters of the two groups were compared: The number of patients who complained of adverse events and their symptoms; GI symptoms quality of life (QOL) score, assessed by the Gastrointestinal Symptom Rating Scale (GSRS), Japanese edition, before and two weeks after beginning treatment; and depressive symptoms assessed by the Self-Rating Depression Scale (SDS), before and 2, 4, and 8 weeks after beginning treatment.

The number of patients who complained of adverse events in the FLV+TJ-43 group (n = 6) was significantly lower than the number complaining in the FLV group (n = 13) (P < 0.05). The number of patients who complained of nausea was also lower in the FLV+TJ-43 group (n = 3) than in the FLV group (n = 9) (P < 0.05). By two weeks after treatment, GSRS scores had improved in the FLV+TJ-43 group, but not in the FLV group. SDS scores were not different between the two groups at any of the assessment points.

This study suggests that Rikkunshi-to reduces FLV-induced adverse events, especially nausea, and improves QOL related to GI symptoms without affecting the antidepressant effect of FLV.