Trajectory of Urine Parameters by Adding Herbal Kampo Medicine Goreisan to Tolvaptan in Patients with Congestive Heart Failure

<b>Background:</b> Even in current guideline-directed medical therapy, including recently introduced vasopressin type 2 receptor antagonist tolvaptan, congestion has not been resolved in patients with heart failure. Kampo medicine goreisan has been receiving considerable attention as an additional therapy for patients who are refractory to conventional diuretics therapy, including tolvaptan. However, the impact of goreisan on urine electrolytes remains uncertain. <b>Methods:</b> Patients with congestive heart failure who received goreisan as an add-on therapy to tolvaptan-incorporated medical therapy were prospectively included. The changes in urine parameters during the first 24 h were assessed as a primary concern. Baseline factors associated with an increase in urine sodium excretion were investigated. <b>Results:</b> A total of 21 patients were included. The median age was 81 (77, 86), and 13 (62%) were men. Twenty-four hours after the initiation of goreisan, urine osmolality decreased significantly, urine sodium level remained unchanged, urine potassium and glucose levels decreased significantly, urine urea nitrogen level tended to decrease, and urine volume tended to increase. The fractional excretion of sodium tended to increase. Baseline plasma B-type natriuretic peptide level had a positive correlation with a change in fractional excretion of sodium from baseline to day 1 (r = 0.52, <i>p</i> = 0.015). <b>Conclusions:</b> Goreisan may increase urine volume via aquaretic and natriuretic effects in patients with congestive heart failure receiving tolvaptan-incorporated medical therapy. Goreisan may have the ability to "modulate" fluid balance depending on congestion status.