古関 竹直

IMPORTANCE: Hyponatremia is an adverse event associated with antipsychotic use; however, comparative evidence among individual second-generation antipsychotics remains limited. OBJECTIVE: To compare the risk of hyponatremia associated with individual second-generation antipsychotics. DESIGN, SETTING, AND PARTICIPANTS: In this retrospective cohort study and disproportionality analysis, data were obtained from the US Food and Drug Administration Adverse Event Reporting System (FAERS; quarter 4 1997 to quarter 3 2023), a dataset provided by the Japan Pharmaceutical Information Center, and a Japanese hospital-based claims database (Medical Data Vision; April 2008 to April 2024). The study adopted a new-user design and included patients routinely prescribed antipsychotics. Patients aged 18 to 69 years with at least 180 days of active medical history preceding the initial antipsychotic prescription, with no history of antipsychotics or hyponatremia during that period, were included. EXPOSURES: Initiation of second-generation antipsychotics. MAIN OUTCOMES AND MEASURES: Hyponatremia associated with individual antipsychotics was compared with that associated with olanzapine. Reporting odds ratios with 95% CIs were calculated for FAERS. The incidence within 180 days of treatment initiation was analyzed for claims database using hazard ratios estimated with stabilized inverse probability of treatment weighting based on propensity scores. RESULTS: In the FAERS database, most antipsychotics showed lower reporting odds ratios for hyponatremia than olanzapine. In a Japanese claims database, among 961 010 patients prescribed antipsychotics, 55 394 were included in the final analysis. The mean (SD) age was 50.4 (14.3) years, and there were 25 839 (46.6%) male and 29 555 (53.4%) female patients. After stabilized inverse probability of treatment weighting, aripiprazole was associated with a significantly lower risk of hyponatremia than olanzapine (adjusted hazard ratio, 0.52; 95% CI, 0.35-0.76), whereas other antipsychotics showed no significant differences. Sensitivity analysis confirmed the robustness of the findings. CONCLUSIONS AND RELEVANCE: In this retrospective cohort study of antipsychotic users, aripiprazole was associated with a lower risk of hyponatremia than was olanzapine. Although residual confounding should be considered, these findings may help inform clinical decision-making for high-risk patients.

BACKGROUND: Cisplatin-induced nephrotoxicity (CIN) is a major dose-limiting adverse event that can lead to both acute and chronic kidney injury. The formation of thiol-cisplatin conjugates within renal tubular cells has been implicated as a key mechanism underlying CIN. Flopropione is an inhibitor of cysteine conjugate β-lyase 1, an enzyme that catalyzes the formation of the thiol-cisplatin conjugate, which might prevent CIN. OBJECTIVE: We designed a clinical trial to evaluate the safety of flopropione in patients receiving cisplatin-based chemotherapy and explore its efficacy in preventing CIN. METHODS: This is a phase 1 and 2a, single-center, randomized, open-label trial conducted in patients undergoing cisplatin therapy. Participants are randomized in a 5:2 ratio per cohort to receive either flopropione or no treatment. On the day of cisplatin administration, the flopropione group receives oral flopropione twice daily (80 mg in cohort 1, 160 mg in cohort 2, and 240 mg in cohort 3). On the following day, all cohorts receive 3 doses of 80 mg of oral flopropione. A step-up dose escalation design is adopted, progressing from cohort 1 to 3 after confirming safety at each level. The primary end point is the safety of flopropione use in combination with cisplatin; the secondary end points include changes in the levels of urinary biomarkers of nephrotoxicity such as neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and kidney injury molecule-1. Blood and urine samples are collected within 48 hours before cisplatin administration and at 24 hours, 48 hours, and 1 week after its initiation for safety and efficacy assessments. RESULTS: The first participant was registered in July 2024. As of January 2026, participant registration is ongoing. The final participant will complete the study by March 2026. Publication of results is expected by March 2027. CONCLUSIONS: This study is expected to contribute to advances in preventive strategies for CIN by providing evidence that inhibition of cysteine conjugate β-lyase 1 by flopropione may attenuate CIN. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs041220021; https://jrct.mhlw.go.jp/en-latest-detail/jRCTs041220021. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/87907.

BACKGROUND: Clozapine is associated with a high risk of central nervous system abnormalities. However, seizure risk related to interactions between clozapine and other antipsychotics remains poorly characterized, and the pharmacological mechanisms underlying these seizures are unclear. OBJECTIVES: We aimed to evaluate safety signals for seizures associated with clozapine augmentation by other antipsychotics and analyze the relationship between these signals and neurotransmitter receptor occupancy profiles. DESIGN: A pharmacovigilance-pharmacodynamic analysis using a spontaneous reporting system. METHODS: This pharmacovigilance study used VigiBase, an adverse drug reaction database maintained by the World Health Organization. Drug-drug interactions (DDIs) between clozapine and other antipsychotics were assessed using the Ω shrinkage measure model. The association between DDI signals and neurotransmitter receptor occupancy was evaluated using linear regression. Robustness was tested using four frequency statistical models: additive, multiplicative, combination risk ratio, and chi-square statistic models. RESULTS: Of 38,758,077 reports in VigiBase between 1990 and 2024, 230,371 involved clozapine. Among antipsychotics classified under ATC code N05A, DDIs with clozapine were detected for amisulpride, chlorpromazine, haloperidol, lurasidone, olanzapine, penfluridol, risperidone, sulpiride, zotepine, and zuclopenthixol. A significant association between dopamine D4 receptor occupancy and the point estimates of signal values was observed in the Ω shrinkage measure model (β = 0.295, 95% confidence interval: 0.119-0.471, p = 0.002) and replicated across all frequency statistical models. CONCLUSIONS: These findings suggest a potential role of dopamine D4 receptor occupancy in seizures associated with clozapine augmentation by other antipsychotics. Further large-scale epidemiological studies are needed to validate these findings.

OBJECTIVES: Sivelestat sodium hydrate (SSH) may be effective in the early stage of acute respiratory distress syndrome (ARDS) before the neutrophil extracellular trap scaffold structure is complete. Therefore, patients with suppression of fibrinolysis (SF) before the secondary fibrinolytic process might benefit from SSH administration. The primary aim of this study was to determine the effect of the SF state and combination therapy on the effect of SSH administration. METHODS: We retrospectively reviewed the data of patients diagnosed with ARDS at Fujita Health University Hospital between July 2005 and December 2016. Patients with ARDS were stratified into the SF and hyperfibrinolysis (HF) groups. Using the fibrin degradation product (FDP)/D-dimer ratio, cut-off values were set as follows: FDP/D-dimer >2 for the HF group and FDP/D-dimer ≤2 for the SF group. The 28-day mortality was the primary endpoint. RESULTS: In total, 168 patients (71 in the HF group and 97 in the SF group) were included in the analysis. The mortality within 28 days was not different based on SSH administration in either group (HF group: p=0.956, SF group: p=0.957). In the SF group, the mortality rate within 28 days in SSH-treated patients who received antithrombotic drugs was significantly higher than that in patients who received SSH only (p<0.05). However, this finding was not present in the HF group (p=0.786). CONCLUSIONS: Concomitant use of SSH and antithrombotic drugs might worsen the treatment outcome of patients with ADRS in the SF state.