Jang David H, Hoffman Robert S, Nelson Lewis S
New York University School of Medicine and Bellevue Hospital, New York, New York and New York City Poison Control Center, New York, NY 10016, USA.
J Emerg Med. 2013 Apr;44(4):781-3. doi: 10.1016/j.jemermed.2012.07.050. Epub 2012 Sep 13.
Flecainide is a class IC antidysrhythmic primarily indicated for ventricular dysrhythmias and supraventricular tachycardia (SVT). Class IC antidysrhythmic overdose has a reported mortality of 22%, and death results from dysrhythmias and cardiovascular collapse. We report a near-fatal flecainide overdose in an 18-day-old treated successfully with sodium bicarbonate.
An 18-day-old, 2 weeks premature, 4-kg boy developed persistently high heart rates (220-240 beats/min) and electrocardiographic changes consistent with SVT. There was minimal response to vagal maneuvers, adenosine, and esmolol, and a transthoracic echocardiogram showed no underlying structural abnormality. The patient was then started on flecainide 4 mg orally every 8 h (Q8h). After the fourth dose he developed lethargy, cold clammy skin, and a heart rate of 40 beats/min with no palpable pulse. The patient was given 0.1 mg of atropine intravenously, with an increase of the heart rate to 160 beats/min. The child's cardiac monitor revealed a wide-complex tachycardia with left bundle branch morphology, with associated pallor and poor capillary refill. Sodium bicarbonate was administered intravenously due to suspected flecainide toxicity. Approximately 5 min after intravenous administration of 10 mEq of 8.4% sodium bicarbonate twice, his rhythm converted to a narrow-complex tachycardia. A serum flecainide concentration was 1360 μg/L (therapeutic, 200-1000 μg/L) drawn 1 h before the cardiac arrest. It was later discovered that a twofold dosing error occurred: the patient received 8 mg Q8h instead of 4 mg Q8h for four doses.
Flecainide toxicity in children is rare, especially in neonates. It is important for clinicians to be able to identify and treat this uncommon poisoning.
氟卡尼是一种IC类抗心律失常药物，主要用于治疗室性心律失常和室上性心动过速（SVT）。据报道，IC类抗心律失常药物过量的死亡率为22%，死亡原因是心律失常和心血管衰竭。我们报告了一例18天大的婴儿氟卡尼过量，经碳酸氢钠成功治疗。
一名18天大、早产2周、体重4公斤的男婴出现持续高心率（220 - 240次/分钟），心电图改变符合室上性心动过速。对迷走神经手法、腺苷和艾司洛尔反应极小，经胸超声心动图显示无潜在结构异常。然后患者开始口服氟卡尼，每8小时4毫克（每8小时一次）。在第四剂后，他出现嗜睡、皮肤湿冷，心率40次/分钟，无脉搏。患者静脉注射0.1毫克阿托品，心率增至160次/分钟。患儿的心脏监护显示宽QRS波心动过速，呈左束支形态，伴有面色苍白和毛细血管再充盈不良。因怀疑氟卡尼中毒，静脉注射了碳酸氢钠。在静脉注射两次10毫当量的8.4%碳酸氢钠后约5分钟，他的心律转为窄QRS波心动过速。心脏骤停前1小时测得血清氟卡尼浓度为1360微克/升（治疗浓度为200 - 1000微克/升）。后来发现出现了两倍剂量错误：患者接受了每8小时8毫克而不是每8小时4毫克的剂量，共四剂。
儿童氟卡尼中毒罕见，尤其是新生儿。临床医生能够识别和治疗这种罕见的中毒情况很重要。
