Direct oral to parenteral anticoagulant transitions: Role of factor Xa inhibitor-specific anti-Xa concentrations.

OBJECTIVES: The increasing use of oral factor Xa inhibitors (FXaI) has led to a growing interest in the clinical utility of laboratory monitoring to enhance safety and effectiveness. Particularly, the use of FXaI-specific anti-Xa concentrations has gained traction and been advocated for several indications, but limited studies have explored the role of anti-Xa concentrations in guiding inpatient transitions from oral to parenteral anticoagulants. Therefore, additional data on such approaches are warranted to help balance bleeding and thrombotic risks in the higher acuity inpatient setting. This study sought to compare two strategies for oral-to-parenteral anticoagulant transitions: FXaI anti-Xa concentration-guided versus standard of care (i.e., per-package insert). STUDY DESIGN: This was an observational, single-center, retrospective cohort study conducted from May 2016 to May 2021. Hospitalized patients converted from an oral FXaI (apixaban or rivaroxaban) to therapeutic parenteral anticoagulation with or without FXaI anti-Xa concentration guidance were reviewed. The primary outcome of major bleeding, according to the International Society on Thrombosis and Hemostasis criteria, was compared between groups. Cox proportional hazard modeling was used to evaluate patient characteristics associated with major bleeding events. RESULTS: A total of 845 patients (388 in the concentration-guided group and 457 in the non-concentration-guided group) met the inclusion criteria. Major bleeding was significantly lower in the concentration-guided versus the non-concentration-guided group (2.2% vs. 11.3%; p < 0.001, respectively). There were no differences between the groups in thromboembolic complications (1.8% concentration guided vs. 1.5% non-concentration guided; p = 0.72) despite a significantly longer time from last oral FXaI dose to parenteral anticoagulant initiation in the concentration-guided group (27.9 h vs. 15.1 h; p < 0.01). The concentration-guided group had an 80% lower risk of major bleeding compared with the non-concentration-guided group (adjusted hazard ratio [HR] 0.20, 95% confidence interval [CI] 0.10-0.39; p < 0.01). CONCLUSIONS: This analysis suggests using FXaI anti-Xa concentrations to guide the transition from oral to parenteral anticoagulants may be beneficial in reducing major bleeds in select patient populations.

Life-threatening hypertriglyceridemia-induced pancreatitis related to alectinib successfully treated by plasmapheresis: A review of the literature on metabolic toxicities associated with anaplastic lymphoma kinase inhibitors.

INTRODUCTION: Actionable mutations are tested as standard of care for all new metastatic non-small cell lung cancers. Tumors harboring an anaplastic lymphoma kinase mutation respond to tyrosine kinase inhibitors targeting anaplastic lymphoma kinase pathway. Patients are monitored for common adverse effects, although we occasionally encounter unexpected side effects. CASE REPORT: A 52-year-old male presented with a right hilar lung mass, and workup revealed a stage IIIA adenocarcinoma. He underwent treatment with concurrent chemoradiation; however, disease recurred one year later with a right hilar mass and contralateral mediastinal lymphadenopathy, biopsy of which resulted positive for adenocarcinoma. Molecular analysis showed anaplastic lymphoma kinase rearrangement and alectinib was started. Six months into therapy, he presented with hematochezia, nausea, and epigastric pain and was diagnosed with acute pancreatitis. Triglyceride level resulted above the measurable level at >5680mg/dL, thought to be the inciting event of pancreatitis.Management and outcome: Despite treatment with intravenous hydration, insulin infusion, and antibiotics, he decompensated with development of respiratory failure, shock requiring intensive care. Therapeutic plasmapheresis was initiated due to persistently elevated triglyceride. Following the third plasmapheresis, triglyceride level decreased to 359 mg/dL. With aggressive multidisciplinary management, he made a complete recovery. Follow-up imaging studies at three and six months show a stable mass-like abnormality in the right hilum without evidence of disease progression. DISCUSSION: Prior to starting alectinib, our patient's triglyceride level was 420 mg/dL. While he consumed alcohol, he had no other traditional risk factor. To our knowledge, this is the first reported case of hypertriglyceridemia-induced acute pancreatitis related to treatment with an anaplastic lymphoma kinase inhibitor.