粒線體腦病變、乳酸血症及類中風症狀 (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes 簡稱 MELAS) 為遺傳性粒線體疾病，臨床表徵常有局 部或全身癲癇發作的表現，在很多案例中，抗癲癇藥物常需合併使用治療。本案例為 44 歲男性因癲癇發作而入院，因反覆癲癇發作及懷疑 MELAS，因癲癇藥物 valproic acid 有粒線體毒性，故調整癲癇藥物使用 phenytoin 及其他抗癲癇藥物，phenytoin 可用於治療大發作、小發作癲癇及癲癇重積狀態，但可能有潛在粒線體毒性，此外 phenytoin 為治療濃度狹窄的藥品，且和多種藥物有交互作用，臨床上需藉由血中濃度 監測以達到良好的治療效果。本篇文章依據文獻查證，進一步探討在 MELAS 的病患 族群 phenytoin 是否為理想的抗癲癇藥物的選擇並藉由此案例提醒醫療人員 phenytoin 藥物動力學以及使用注意事項。

 

(MELAS) syndrome is a maternally inherited multisystemic disorder that occurs as a result of mutations in the mitochondrial DNA. Common features of this syndrome include focal or generalized seizures. In many cases, multiple antiepileptic drugs (AEDs) are needed to achieve seizure control. We herein report the case of a 44-yearold man who was hospitalized due to a focal seizure attack. The patient had recurrent focal epileptic seizures after hospitalization, and MELAS syndrome was suspected. Subsequently, in order to limit the iatrogenic mitochondrial toxicity, valproic acid was replaced with an adjusted multiple AED regime including phenytoin. Although phenytoin is often used to treat tonic-clonic (grand mal) or partial seizures and generalized status epilepticus, it may exhibit potential mitochondrial toxicity and affect mitochondrial metabolism. Other drawbacks of phenytoin included its narrow therapeutic range, need for monitoring its concentration in the blood, and its widescale drug interactions. Based on the present case study and literature review, further exploration whether phenytoin is an ideal AED option in patients with MELAS is warranted. This case may also raise awareness regarding the pharmacokinetics of phenytoin and precautions for its use.

 

Submitted for publication: 2021.7.12; Accepted for publication: 2021.10.20