Appalachian Regional Healthcare, Whitesburg, KY, USA.
Jacobi Medical Center, Bronx, NY, USA.
J Investig Med High Impact Case Rep. 2021 Jan-Dec;9:23247096211056492. doi: 10.1177/23247096211056492.
Dofetilide, a class III antiarrhythmic, is widely used in the treatment of cardiac arrhythmias. Antiarrhythmic drugs can have a long duration of action that prolongs the QT interval. This causes bradycardia that predisposes to R-on-T phenomenon subsequently leading to torsades de pointes (TdP). This necessitates constant monitoring to prevent or treat ventricular arrhythmias or bradycardia associated with cardiac medications. Although extremely rare, dofetilide overdose has been described in the literature. However, no evidence found in the current literature required prolonged intervention after the initial acute stabilization, leading to scarcity of data for treatment of ongoing dofetilide overdose. We present the case of an intentional dofetilide overdose in a 61-year-old Caucasian woman with a history of congestive heart failure, atrial fibrillation, stage IIIb chronic kidney disease, diabetes mellitus type II, hypothyroidism, morbid obesity, and hypertension that required extensive interventions for refractory TdP that lasted 4 days. Therapeutic as well as excess dosage of dofetilide can lead to TdP, which is usually controlled by decreasing the dose or terminating drug administration. If the arrhythmia is not resolved, guidelines recommend management with activated charcoal if ingestion is within 15 minutes, followed by administration of 2 g IV (intravenous) magnesium and addressing the electrolyte imbalance. However, if the arrhythmia is persistent due to ongoing dofetilide toxicity, isoproterenol is given as a bridge to overdrive pacing and dopamine is used as an alternative to isoproterenol.
多非利特是一种 III 类抗心律失常药物，广泛用于治疗心律失常。抗心律失常药物的作用持续时间较长，会延长 QT 间期。这会导致心动过缓，易发生 R-on-T 现象，随后导致尖端扭转型室性心动过速（TdP）。这需要持续监测，以预防或治疗与心脏药物相关的室性心律失常或心动过缓。虽然极为罕见，但文献中已有多非利特过量的描述。然而，目前文献中没有发现需要在初始急性稳定后进行长时间干预的证据，导致多非利特持续过量治疗的数据稀缺。我们报告了一例 61 岁白人女性故意服用多非利特过量的病例，该患者有充血性心力衰竭、心房颤动、IIIb 期慢性肾脏病、2 型糖尿病、甲状腺功能减退、病态肥胖和高血压病史，需要广泛干预难治性 TdP，持续 4 天。治疗剂量和过量的多非利特都可能导致 TdP，通常通过减少剂量或终止药物治疗来控制。如果心律失常未得到解决，指南建议如果摄入时间在 15 分钟内，可使用活性炭治疗，并给予 2 g IV（静脉内）镁，纠正电解质失衡。然而，如果心律失常由于持续的多非利特毒性而持续存在，可给予异丙肾上腺素作为超速起搏的桥接，或使用多巴胺作为异丙肾上腺素的替代药物。
