We hypothesized that there is reduced efficacy of fluorinated pyrimidines, such as capecitabine, caused by low active folic acid levels induced by vitamin B12 deficiency, due to proton pump inhibitors (PPIs), and that this can be recovered by the administration of leucovorin (LV). Thus, we retrospectively analyzed the effects of PPIs on adjuvant tegafur-uracil (UFT) plus LV for stage II/III colorectal cancer (CRC). Patients newly diagnosed with stage II/III CRC who underwent curative surgery and received adjuvant UFT/LV therapy between January 2013 and June 2018 were included. The primary endpoint was the difference in relapse-free survival (RFS) between the PPI and non-PPI groups. Data from 396 eligible patients were evaluated, 84 of whom received PPIs. There were 93 relapse events and 57 deaths across the groups. RFS rates at 5 years were 73.8% (95% confidence interval [CI], 62.9-81.9%) and 77.1% (95% CI, 72.0-81.4%) in the PPI and non-PPI groups, respectively. Cox regression analysis showed no significant differences in RFS between the PPI and non-PPI groups (hazard ratio, 1.16; 95% CI, 0.72-1.87; P = 0.539). Our findings suggest that the concomitant use of PPIs does not significantly reduce the efficacy of adjuvant UFT/LV treatment for patients with stage II/III CRC.

OBJECTIVE: The aim of this study was to investigate the risk of hemorrhage in concomitant therapy with direct oral anticoagulants (DOACs) and class IV antiarrhythmic drugs. MATERIALS AND METHODS: First, disproportionality analysis (DPA) was performed using the Japanese Adverse Drug Event Report (JADER) database to investigate the risk of hemorrhage with DOACs. Second, a cohort study was performed using electronic medical record data to confirm the results of the JADER analysis. RESULTS: In the JADER analysis, hemorrhage was significantly associated with treatment with edoxaban and verapamil (reporting odds ratio = 1.66; 95% confidence interval (CI) = 1.04 - 2.67). The cohort study revealed that hemorrhage incidence significantly differed between the verapamil-treated group and the bepridil-treated group, with a higher risk for hemorrhage in the verapamil group (log-rank test: p < 0.001). The multivariate Cox proportional hazards model also showed that the verapamil and DOAC combination was significantly associated with hemorrhage events compared with the bepridil and DOAC combination (hazard ratio (HR): 2.87, 95% CI: 1.17 - 7.07, p = 0.022). Furthermore, creatinine clearance (Ccr) ≥ 50 mL/min was significantly associated with hemorrhage events (HR: 2.72, 95% CI: 1.03 - 7.18, p = 0.043), and verapamil was significantly associated with hemorrhage in patients with Ccr ≥ 50 mL/min (HR: 3.58, 95% CI: 1.36 - 9.39, p = 0.010) but not in patients with Ccr < 50 mL/min. CONCLUSION: Verapamil increases the risk of hemorrhage in patients on DOACs. Dose adjustment of DOACs based on renal function may prevent hemorrhage when verapamil is concomitantly administered.

BACKGROUND: Atrial fibrillation (AF) is a major risk factor for the development of stroke and silent cerebral infarct (SCI). Additionally, AF is independently associated with neurological disorders, including cognitive impairment and dementia. Although oral anticoagulants (OACs) are used to reduce the risk of development of stroke and SCI in patients with AF, it is unclear whether OACs reduce the risk of dementia. OBJECTIVE: This study aimed to investigate the association between OAC use and dementia in relatively young patients with AF. Moreover, the impact of medication adherence on the association between OAC use and the risk of dementia was examined. PATIENTS AND METHODS: This retrospective cohort study was conducted using a large claims database-Japan Medical Data Center, Inc. (JMDC)-from which newly diagnosed patients with AF younger than 75 years of age were identified. We analyzed medication adherence using the medication possession ratio (MPR). The dementia risk was compared between the OAC and non-OAC groups using Cox proportional hazards regression analysis and the Kaplan-Meier method after propensity score matching. Similarly, the MPR-classified and non-OAC groups were also compared. RESULTS: OAC administration was not associated with the risk of dementia in the entire cohort (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.40-1.08; p = 0.098); however, OAC administration in patients with an MPR ≥90% was significantly associated with a lower risk of dementia (HR 0.45, 95% CI 0.25-0.81; p = 0.008). Meanwhile, direct OAC (DOAC) and warfarin (WF) administration was not associated with the risk of dementia regardless of MPR. Kaplan-Meier analysis revealed a significant difference in the incidence of dementia between the MPR ≥ 90% OAC and non-OAC groups (log-rank test: p = 0.006). However, no difference was observed in the incidence of dementia between the MPR ≥ 90% WF and non-OAC groups, or between the MPR ≥ 90% DOAC and non-OAC groups. CONCLUSIONS: OAC administration was not associated with the risk of dementia in relatively young patients with AF; however, when limited to patients with an MPR ≥ 90%, OAC administration reduced the risk of dementia. Our results suggest that the association between OAC use and dementia should be evaluated while considering medication adherence.