Abstract
We often encounter patients with congestive heart failure refractory to conventional diuretics therapy, and Kampo Goreisan is receiving great concern to mediate body water balance particularly for such a cohort. However, its detailed biological mechanism remains uncertain. We had two hospitalized patients with congestive heart failure receiving tolvaptan. Following the administration of Goreisan, both urine cyclic adenosine monophosphate concentration and urine aquaporin-2 concentration decreased, accompanied by incremental diluted urine volume. Although further studies are warranted to establish therapeutic strategy, Goreisan might be a promising therapeutic tool for those with congestive heart failure refractory to conventional diuretics including tolvaptan, via pleiotropic effects including suppression of aquaporin-incorporated water reabsorption system.