Effectiveness of Long-Term Shichimotsukokato Administration on the eGFR Slope in Patients With Chronic Kidney Disease: A Retrospective Single-Arm Study

Introduction The prevalence of chronic kidney disease (CKD) continues to rise worldwide. Patients with CKD are exposed to increased risks of end-stage kidney disease, cardiovascular events, and mortality. Despite recent pharmacological advances, therapeutic options for CKD remain limited. Shichimotsukokato (SCMKT), a representative Kampo formula in Japanese Traditional Medicine composed of seven crude drugs, has historically been used to treat CKD. Experimental studies have demonstrated its renoprotective and antihypertensive effects. However, the clinical evidence of SCMKT for CKD patients remains limited. To evaluate the effectiveness of the long-term SCMKT administration on renal function, proteinuria, and blood pressure in patients with CKD, we conducted a retrospective, single-arm, observational study. Methods This study targeted outpatients with CKD who were treated with SCMKT. The study was conducted at Fukushima Medical University Aizu Medical Center and Tenjinbashi Clinic from April 2019 to May 2025 (UMIN000058358). Eligible patients were aged ≥18 years, had been prescribed SCMKT continuously for one year, and had available estimated glomerular filtration rate (eGFR) data from one year before initiation, at initiation, and one year after the initiation of SCMKT. The primary endpoint was the change in the eGFR slope between the pre-treatment and post-treatment periods. The pre-treatment eGFR slope was determined from one year before the initiation of SCMKT, and the post-treatment slope from initiation to one year after. The eGFR slope was calculated using the least-squares regression method. Secondary endpoints included changes in systolic and diastolic blood pressure, qualitative proteinuria, and the occurrence of adverse events. Results A total of 21 patients who were prescribed SCMKT were screened from both institutions. Finally, 12 patients were included in our study (mean age, 77.8 years; male, seven patients (58.3%)). The mean baseline eGFR was 38.7 ± 10.0 mL/min/1.73 m², and 9 patients (75.0 %) were classified as CKD stage G3b. Hypertensive nephrosclerosis was the most common primary cause of CKD. There were 11 patients (91.7 %) with concomitant hypertension, and 9 patients (75.0 %) were prescribed renin-angiotensin-aldosterone system (RAAS) inhibitors. The mean daily dose of SCMKT (Tsumura & Co., Tokyo, Japan) was 5.6 g. The mean eGFR slope significantly improved after SCMKT administration compared with the pre-treatment period (pre-treatment vs. post-treatment, -4.9 ± 7.3 vs. 5.4 ± 5.4 mL/min/1.73 m²/year; <i>P</i> = 0.002). In contrast, there were no significant changes in systolic or diastolic blood pressure (132.9 ± 15.5 vs. 135.2 ± 13.4 mmHg; 70.2 ± 13.2 vs. 73.1 ± 7.5 mmHg, respectively), and qualitative urine protein did not show a marked change. No clinical information on serious adverse events that were potentially associated with SCMKT was available. Sensitivity analyses excluding patients with changes in RAAS inhibitor therapy confirmed the robustness of our findings. Conclusions The one-year prescription of SCMKT was safe and may help preserve the eGFR slope in patients with CKD. Further prospective studies are warranted to confirm the renoprotective effects of SCMKT.