Effect of Hangeshashin-To (Japanese Herbal Medicine Tj-14) on Tolerability of Irinotecan: Propensity Score and Instrumental Variable Analyses.

Irinotecan hydrochloride (CPT-11) is used to treat a wide spectrum of malignant tumors. Hangeshashin-to (Japanese herbal medicine TJ-14) is reportedly effective in preventing and controlling diarrhea associated with CPT-11. However, the effect of TJ-14 on tolerability of chemotherapy with CPT-11 has not been fully investigated. We used the Japanese Diagnosis Procedure Combination inpatient database to retrospectively identify patients who had received CPT-11 on their first admission with and without TJ-14. Patients who did receive TJ-14 (N = 7092) received CPT-11 more often and in larger doses than those who did not receive TJ-14 (N = 82,019). The incidence rate ratio of CPT-11 administration was 1.34 for frequency (95% confidence interval [CI], 1.31⁻1.38; p < 0.001), and 1.16 for total dose (95% CI, 1.14⁻1.19; p < 0.001) according to stabilized inverse probability treatment weighting using propensity scores. Instrumental variable analysis showed similar trends. In-hospital mortality was significantly lower in patients who received TJ-14 than in those who did not. Odds ratios of in-hospital death in patients receiving TJ-14 was 0.81 (95% CI, 0.71⁻0.93; p = 0.002) according to stabilized inverse probability treatment weighting using propensity scores and 0.42 (95% CI, 0.22⁻0.81; p = 0.009) according to instrumental variable analysis. Our findings indicate that TJ-14 improve the tolerability of CPT-11.