Action of Rikkunshi-To on the rivastigmine-induced nausea in mice

Rivastigmine, which is a cholinesterase inhibitor used for the treatment of mild to moderate Alzheimer's disease, is known to be associated with significant gastrointestinal (GI) adverse reactions including nausea, vomiting, anorexia. If severe GI adverse reactions are observed during the course of treatment, the patient should be instructed to stop treatment. Rikkunshi-To (RKT), a traditional herbal Japanese medicine, has been prescribed for patients with various GI symptoms, and we have reported that RKT on therapy-induced nausea in mice. We also reported that pica, kaolin ingestion behavior, could be used to evaluate nausea in mice; thus, in this study, we investigated the effects of rivastigmine on pica in mice and the effects of RKT on inhibition of rivastigmine-induced nausea.