Holtzer C D, Reisner-Keller L A
School of Pharmacy, University of California, San Francisco 94110, USA.
Ann Pharmacother. 1997 Apr;31(4):435-7. doi: 10.1177/106002809703100409.
To describe a patient with severe thrombocytopenia induced by the administration of phenytoin for prevention of seizures. A review of the literature supplements this case description to alert clinicians to this potentially serious hematologic reaction.
A woman who had experienced two seizures was prescribed phenytoin to prevent seizure recurrence. Further evaluation revealed a tumor, which was resected, and phenytoin was continued. Thrombocytopenia was noted 15 days after initiation of phenytoin, which was replaced with phenobarbital. Platelet transfusion and administration of intravenous immune globulin were used to treat her thrombocytopenia. Platelets were within the normal range by day 8 after the operation.
Phenytoin has been reported to induce various hematologic reactions, including thrombocytopenia. An intermediate epoxide metabolite of phenytoin is suspected as the cause of platelet destruction, which may occur via a complement-antibody reaction. Our patient experienced some confusion as a possible consequence of her thrombocytopenia, but no long-term sequelae followed.
Due to widespread use of phenytoin, clinicians must recognize the potential for the rare but serious adverse effect of thrombocytopenia, particularly in the neurosurgical population. Confusion, as observed in our patient, makes postoperative evaluation of central nervous system and cognitive function difficult, and can obscure the clinical presentation. At its worst extreme, disruption of platelet function may produce cerebral hemorrhage, which results in long-term functional deficits.
描述一例因服用苯妥英钠预防癫痫发作而导致严重血小板减少的患者。文献回顾补充了该病例描述，以提醒临床医生注意这种潜在的严重血液学反应。
一名有两次癫痫发作史的女性患者被处方使用苯妥英钠预防癫痫复发。进一步评估发现一个肿瘤，该肿瘤被切除，苯妥英钠继续使用。在开始使用苯妥英钠15天后发现血小板减少，遂将其替换为苯巴比妥。使用血小板输注和静脉注射免疫球蛋白治疗她的血小板减少症。术后第8天血小板恢复到正常范围。
据报道，苯妥英钠可引发各种血液学反应，包括血小板减少。苯妥英钠的一种中间环氧化物代谢产物被怀疑是血小板破坏的原因，这可能通过补体-抗体反应发生。我们的患者因血小板减少可能出现了一些意识模糊，但未留下长期后遗症。
由于苯妥英钠的广泛使用，临床医生必须认识到血小板减少这种罕见但严重的不良反应的可能性，尤其是在神经外科患者中。如我们的患者所观察到的意识模糊，会使术后中枢神经系统和认知功能的评估变得困难，并可能掩盖临床表现。在最严重的情况下，血小板功能紊乱可能导致脑出血，从而导致长期功能缺陷。
