St. Joseph Mercy Oakland, Internal Medicine/Cardiology, Pontiac, Michigan 48341, USA.
Cardiol J. 2010;17(5):509-11.
The histamine I receptor antagonist diphenhydramine is a freely available, over the counter medication for sleep and the most frequently used antihistamine drug. It inhibits the fast sodium channels and, at higher concentrations, the repolarising potassium channels, particularly Ikr which leads to prolongation of the action potential and the QT interval. The toxicity of diphenhydramine is dose-dependent, with a critical dose limit of 1.0 g. We report a case of a young woman who consumed more than 3 g of diphenhydramine in the setting of alcohol intoxication and developed QTc prolongation with nonsustained polymorphic ventricular tachycardia. These changes reverted to normal with supportive treatment. An overdose of diphenhydramine with concomitant alcohol use can induce torsade de pointes in an otherwise normal heart.
组胺 H1 受体拮抗剂苯海拉明是一种可自由获得的、非处方的用于睡眠的药物，也是最常用的抗组胺药物。它可抑制快速钠离子通道，在较高浓度下还可抑制复极化钾通道，特别是 Ikr，这导致动作电位和 QT 间期延长。苯海拉明的毒性与剂量有关，临界剂量限值为 1.0 克。我们报告了一例年轻女性在酒精中毒的情况下摄入超过 3 克苯海拉明的病例，出现 QTc 延长和非持续多形性室性心动过速。这些变化在支持性治疗后恢复正常。在正常心脏中，苯海拉明过量合并酒精使用可引起尖端扭转型室性心动过速。
