Egelund Eric F, Mohamed MohamedEslam F, Fennelly Kevin P, Peloquin Charles A
University of Florida, Gainesville, FL, USA.
J Pharm Technol. 2014 Jun;30(3):93-96. doi: 10.1177/8755122514523934. Epub 2014 Feb 12.
. To report a probable interaction between rifampin and carbamazepine, likely leading to a seizure, and to review conflicting reports regarding this interaction. . A 55-year-old female was treated with carbamazepine 200 mg 3 times daily for grand mal seizures, with excellent control. A 6-hour postdose carbamazepine concentration was 10.7 µg/mL (therapeutic range = 4-10 µg/mL). After she was diagnosed with pulmonary complex, she received rifampin 300 mg twice daily, ethambutol 800 mg daily, and clarithromycin 500 mg twice daily. At first clinic visit, rifampin was changed to 600 mg daily, and clarithromycin was replaced with azithromycin 250 mg daily. A 4-hour postdose carbamazepine concentration was 7.1 µg/mL. Two weeks later, the patient experienced a seizure (no carbamazepine concentration reported at that time), but admitted to missing doses of carbamazepine. After experiencing 2 more seizures, the patient stopped taking rifampin. Subsequently, the carbamazepine dose was increased to 400 mg twice daily and rifampin was restarted at 600 mg daily. Two follow-up peak carbamazepine concentrations were 4.7 µg/mL and 4.4 µg/mL, with no reported seizures. No additional factors were identified as potential causes of the seizures or the lower carbamazepine concentrations. A Drug Interaction Probability Scale score of 6 indicates a probable interaction. . Conflicting reports exist regarding the effect of rifampin on carbamazepine concentrations, likely reflecting rifampin's ability to display time-dependent, mixed effects on transporters and cytochrome P450 enzymes. . Our case report describes a patient who experienced seizures after the addition of rifampin to her regimen, followed by lower peak concentrations of carbamazepine. Therapeutic drug monitoring in patients receiving both rifampin and carbamazepine is recommended to help clinicians optimize drug therapy.
报告利福平与卡马西平之间可能的相互作用，这种相互作用可能导致癫痫发作，并回顾关于这种相互作用的相互矛盾的报告。一名55岁女性因全身性癫痫发作接受卡马西平治疗，每日3次，每次200mg，病情得到良好控制。给药后6小时卡马西平浓度为10.7μg/mL（治疗范围=4 - 10μg/mL）。在她被诊断为肺部复杂性疾病后，接受利福平每日2次，每次300mg，乙胺丁醇每日800mg，克拉霉素每日2次，每次500mg治疗。在首次门诊就诊时，利福平改为每日600mg，克拉霉素被阿奇霉素每日250mg替代。给药后4小时卡马西平浓度为7.1μg/mL。两周后，患者经历了一次癫痫发作（当时未报告卡马西平浓度），但承认漏服了卡马西平。在又经历了2次癫痫发作后，患者停止服用利福平。随后，卡马西平剂量增加至每日2次，每次400mg，利福平重新开始每日600mg服用。两次随访的卡马西平峰值浓度分别为4.7μg/mL和4.4μg/mL，未报告癫痫发作。未发现其他因素是癫痫发作或卡马西平浓度降低的潜在原因。药物相互作用概率量表评分为6表明可能存在相互作用。关于利福平对卡马西平浓度的影响存在相互矛盾的报告，这可能反映了利福平对转运体和细胞色素P450酶表现出时间依赖性、混合效应的能力。我们的病例报告描述了一名患者，在其治疗方案中添加利福平后出现癫痫发作，随后卡马西平峰值浓度降低。建议对同时接受利福平和卡马西平治疗的患者进行治疗药物监测，以帮助临床医生优化药物治疗。
