Maneerot Taweesak, Saelue Pirun, Sangiemchoey Antida
Department of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, THA.
Hematology Unit, Division of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, THA.
Cureus. 2024 May 20;16(5):e60669. doi: 10.7759/cureus.60669. eCollection 2024 May.
Phenytoin is a commonly prescribed antiepileptic medication for the prevention and treatment of tonic-clonic or partial seizures. Thrombocytopenia is a rare and serious adverse effect of phenytoin. This case report presents the case of a patient with severe thrombocytopenia induced by phenytoin for the treatment of tonic-clonic seizures. A 63-year-old male received 300 mg/day of phenytoin for the treatment of tonic-clonic seizures. Seven days after receiving the first dose of phenytoin, he was diagnosed with severe thrombocytopenia (platelet count 44 x 10/L) without hemorrhage. Phenytoin was discontinued, and seizures were controlled with levetiracetam. Seven days after stopping phenytoin, his daily platelet count improved from 44 to 177 x 10/L. The Naranjo algorithm score of 7 was at a probable level for phenytoin-induced thrombocytopenia. Thrombocytopenia is a serious adverse drug reaction that can result in life-threatening bleeding. Phenytoin-induced thrombocytopenia commonly begins 1-90 days after administration, and the recovery time is 3-21 days. The potential mechanism of phenytoin-induced thrombocytopenia is drug-induced immune thrombocytopenia. Drugs that enhance the concentration of phenytoin epoxide may be a contributing factor in phenytoin-induced thrombocytopenia. Phenytoin-induced thrombocytopenia is a rare but serious hematological complication. It should be recognized early, particularly in patients with a high risk of hemorrhage or concurrently with medications that increase phenytoin epoxide. Regularly consecutive complete blood count tests may be essential in order to detect an early decrease in platelet count in these patients.
苯妥英钠是一种常用于预防和治疗强直阵挛性发作或部分性发作的抗癫痫药物。血小板减少是苯妥英钠罕见且严重的不良反应。本病例报告介绍了一名因苯妥英钠治疗强直阵挛性发作而导致严重血小板减少的患者。一名63岁男性接受300毫克/天的苯妥英钠治疗强直阵挛性发作。在接受第一剂苯妥英钠7天后，他被诊断为严重血小板减少（血小板计数44×10⁹/L）且无出血症状。停用苯妥英钠，改用左乙拉西坦控制癫痫发作。停用苯妥英钠7天后，他的每日血小板计数从44×10⁹/L升至177×10⁹/L。根据Naranjo算法评分7分，苯妥英钠所致血小板减少症可能性较大。血小板减少是一种严重的药物不良反应，可导致危及生命的出血。苯妥英钠所致血小板减少症通常在用药后1 - 90天开始出现，恢复时间为3 - 21天。苯妥英钠所致血小板减少症的潜在机制是药物性免疫性血小板减少。提高苯妥英环氧化物浓度的药物可能是苯妥英钠所致血小板减少症的一个促成因素。苯妥英钠所致血小板减少症是一种罕见但严重的血液学并发症。应尽早识别，尤其是在有高出血风险的患者中或与增加苯妥英环氧化物的药物同时使用时。为了在这些患者中检测到血小板计数的早期下降，定期连续进行全血细胞计数检查可能至关重要。
