苯海拉明中毒致失语一例

Aphasia Caused by Diphenhydramine Poisoning:A Case Report

苯海拉明属抗组胺类药物,口服生物利用度为50%,具有分子量小、血浆蛋白结合率高的特点。其不良反应主要有:中枢神经系统抑制表现;呼吸困难、胸闷、咳嗽、肌张力障碍等;偶可引起皮疹、粒细胞减少,贫血及心律紊乱。苯海拉明中毒程度与给药剂量密切相关,服用苯海拉明1 g以上即可引起谵妄、精神错乱、癫痫、昏迷等严重的中毒症状。本文报道1例患者共服用苯海拉明5 g,血药浓度高达4.5 mg/L,在服药后24 h内出现罕见的失语表现。其救治措施具体有:(1)早期洗胃:但该类患者多出现昏迷、牙关紧闭,故应慎重,防止出现误吸等并发症;(2)血液净化治疗:苯海拉明对血液透析效果较差,可选用血液灌流等方法;(3)支持治疗;(4)防治继发器官功能损害:应监测肝功能、肾功能、血肌红蛋白等。

As a kind of antihistamine drug,diphenhydramine is characterized by small molecular weight and high plasma protein binding rate with an oral bioavailability of 50%.Its adverse effects include central nervous system inhibition,dyspnea,chest distress,cough and dystonia,and sometimes it can also cause rash,granulocytopenia,anemia and irregular heart rhythm.The severity of diphenhydramine poisoning is closely related to diphenhydramine dose.Taking diphenhydramine over 1 g can cause delirium,abalienatio mentis,epilepsy and coma.The reported case took 5 g diphenhydramine and showed aphasia within 24 h after taking the medicine with a blood concentration of 4.5 mg/L.Treatments for this patient include：（1） Gastric lavage in early time.Due to the coma and clenched teeth,gastric lavage should be performed carefully to prevent complications like aspiration.（2） Blood purification.Blood dialysis is of bad effect on diphenhydramine,blood perfusion should be selected instead.（3） Supportive treatment.（4） Prevention and treatment of functional lesion in secondary organs.Liver function,renal function and blood myoglobin should be monitored.