Bell W L, Crawford I L, Shiu G K
Department of Neurology, University of Texas Southwestern Medical Center, Dallas.
Epilepsia. 1993 Nov-Dec;34(6):1102-4. doi: 10.1111/j.1528-1157.1993.tb02140.x.
A 28-year-old man with seizures well controlled with carbamazepine (CBZ) and valproate (VPA) developed generalized convulsive status epilepticus three days after his CBZ tablets became wet during a rainstorm while he was camping out. He continued the CBZ but avoided ingesting obviously disintegrating tablets. The VPA was not exposed to excessive moisture. Previous random CBZ blood levels had been in the range of 9-13 micrograms/ml; at the time of admission to the emergency room the level had decreased to 3.8 micrograms/ml. The VPA level did not change significantly from baseline. The moisture-exposed CBZ tablets were of expected weight but were swollen and enlarged. Analysis of these tablets by USP paddle method 2 demonstrated a mean dissolution of 16% at 60 min as compared with > 80% for fresh CBZ tablets. After final dissolution of the moisture-exposed CBZ tablets, normal quantities of active drug were noted. We propose that poor dissolution of moisture-exposed CBZ tablets results in reduced bioavailability. We urge caution in the packaging and storage of CBZ to avoid exposure to moisture.
一名28岁男性，其癫痫发作通过卡马西平（CBZ）和丙戊酸（VPA）得到良好控制。在一次露营时，他的CBZ片剂在暴雨中受潮，三天后出现全身惊厥性癫痫持续状态。他继续服用CBZ，但避免服用明显已经崩解的片剂。VPA未接触到过多水分。之前随机检测的CBZ血药浓度在9 - 13微克/毫升范围内；入院时该浓度降至3.8微克/毫升。VPA浓度与基线相比无显著变化。受潮的CBZ片剂重量符合预期，但出现肿胀和变大。采用美国药典桨法2对这些片剂进行分析，结果显示在60分钟时平均溶出度为16%，而新鲜CBZ片剂的溶出度>80%。在受潮的CBZ片剂最终溶解后，观察到活性药物含量正常。我们认为，受潮的CBZ片剂溶出度差导致生物利用度降低。我们敦促在CBZ的包装和储存过程中要小心，避免接触水分。
