Causes of Acute Phenytoin Intoxication: A Clinical Analysis of 21 Cases

急性phenytoin中毒的原因－21個病例的臨床分析

林小鈴(Shiao-Lin Lin) ； 鍾明耀(Ming-Yao Chung)

《Journal of Medical Sciences》 12卷2期 (1991/10) Pp. 124-133

摘要

本報告收集自民國73年至78年間住台大醫院神經科病房，診斷為急性phenytoin中毒的病例，計21例。除1例因糖尿病多發性神經病變服用phenytoin外，其餘20例為癲癇病人。其中7例併服用其他抗癲癇藥物，2例服用中藥。總計所有病例，年齡分佈在14歲至74歲，血中phenytoin濃度於第一次診視中毒症狀時在22.8至79.9 μg/ml之範圍。急性phenytoin中毒症狀於第一次診視時依次為眼顫（100％），運動失調（90％），頭暈（71％），意識障礙（48％），語音不清（38％），嘔吐（33％），複視或視力模糊（19％）與癲癇發作次數增加（5％）。中毒原因歸納為三類。第一類病例（4例，19％）為使用一般維持劑量(4－6 mg/kg/day)；第二類病例（8例，38％）為使用超過一般維持劑量（即大於4－6 mg/kg/day），其中2例使用中藥－各1例使用中藥丸與中藥粉，這些後經化驗為phenytoin與phenobarbital的混合；第三類病例（9例，43％）為病人自行使用藥物不當，其中6例為藥物醫從性差，2例係自殺服食過量，另1例為誤食藥物。phenytoin在台灣不論是在教學醫院或一般診所，相當普遍的被使用於癲癇的治療，急性中毒的病例不少見，此報告目的在藉分析與整理其臨床表癥與原因，期有助於醫師與病人更了解phenytoin的使用與檢驗血中藥物濃度的重要性，以減少急性中毒的事件發生。

並列摘要

This study is a retrospective review of clinical records 21 patients with a diagnosis of acute phenytoin (PHT) intoxication admitted between 1984 and 1989 to the neurological ward of National Taiwan University Hospital (NTUH). We study their seizure profiles, antiepileptic medications, acute toxic reaction, serum levels of antiepileptic drugs and causes of intoxication. Except a case of diabetic polyneuropathy, the others were all epileptic patients. Sixteen patients had seizure frequency once per month or more, and 5 patients even had clusters of seizures or status attacks. Seven patients received polytherapy of antiepileptic drugs and 2 patients accepted Chinese medicine just before the admission. The range of serum PHT concentration was 22.8-79.9 μg/ml. The clincal manifestations of acute intoxication included: nystagmus (100%), ataxia (90%), dizziness (71%), mental change (48%), dysarthria (38%), nausea and vomiting (33%), diplopia or blurred vision (19%) and increases seizure frequency (5%). We divided all patients into 3 groups according to the cause of overdose. Group 1 (4 cases, 19%) consisted of those who received the usual maintenance dose of PHT (4-6 mg/kg/day), group 2 (8 cases, 38%) were patients given above the usual maintenance dose of PHT, and group 3 (9 cases, 43%) comprised patients who were intoxicated due to poor compliance with an inappropriate dose self-adjustment (6 patients), suicidal attempt (2 patients), or accidental overdose by mistake (1 patient). Two patients in group 2 took Chinese medicine in the form of powder or pill from the local doctor and the drug was identified to be PHT and Phenobarbital (PB) mixture. Iatrogenic overdose and overdose due to the patient's poor compliance were the major causes of acute PHT intoxication. It implies the importance of the doctor's correct way of prescription of PHT (according to the patient's body weight and medical condition such as hepatic disease or simultaneous use of other drugs) and the patient's understanding of correct way of taking PHT. The problem of taking Chinese drug containing PHT and other antiepileptic drugs deserves people's attention.

並列關鍵字

phenytoin ； PHT ； intoxication ； phenobarbital ； PB ； poor compliance