1043-3155 Pediatr Neurol Briefs pedneurbriefs Pediatr Neurol Briefs Pediatric Neurology Briefs Pediatr Neurol Briefs 2166-6482 1043-3155 2166-3155 Pediatric Neurology Briefs Publishers Chicago, IL, USA PNB-8-04-a 10.15844/pedneurbriefs-8-1-6 Anticonvulsant Toxicity Neurology Pediatrics Nervous System Diseases Child Development Brain Diseases Neurosurgery Child Infant Carbamazepine Toxicity with Generic Substitution http://orcid.org/0000-0002-0173-7931 Millichap J. Gordon MD 1 2 * Division of Neurology, Children's Memorial Hospital, Chicago, IL Departments of Pediatrics and Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL Correspondence: Dr. J. Gordon Millichap, E-mail: jgmillichap@northwestern.edu 01 1994 01 06 2016 8 1 4 4 Copyright: © 1994 The Author(s) 1994 This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Carbamazepine toxicity resulting from generic substitution

Two 6-year-old children with carbamazepine (CBZ) toxicity, reported from the University of Miami School of Medicine, were found to have 22% and 41% increases in serum CBZ levels after substitution of Tegretol with the generic brand, Epitol, because of insurance company policies.

 Carbamazepine Toxicity Nystagmus Tegretol

Two 6-year-old children with carbamazepine (CBZ) toxicity, reported from the University of Miami School of Medicine, were found to have 22% and 41% increases in serum CBZ levels after substitution of Tegretol with the generic brand, Epitol, because of insurance company policies. Adverse effects included lethargy, ataxia, slurred speech, and nystagmus. When dosage was adjusted, symptoms of toxicity resolved. [1]

COMMENT. Generic substitution of Tegretol has previously been associated with lowered serum levels of CBZ and seizure exacerbation. Reduced bioavailability is also reported with moisture-exposed CBZ, resulting in status epilepticus [2]. Gilman et al have documented 2 cases of increased bioavailability with Epitol substitution, one of 4 generic carbamazepine products available in the US. In 1988, 70 million CBZ tablets were recalled because of bioinequivalence and clinical seizure exacerbation [3]. Factors other than generic substitution may account for significant variations in CBZ concentrations, including interlot variability, exposure of drug to excessive heat or moisture, food and drug interactions, sample timing, and patient compliance.

 Gilman JT Alvarez LA Duchowny M Carbamazepine toxicity resulting from generic substitution Neurology 1993 Dec 43 12 2696 2697 10.1212/WNL.43.12.2696 8255480 Bell WL Crawford IL Shiu GK Reduced bioavailability of moisture-exposed carbamazepine resulting in status epilepticus Epilepsia 1993 Nov-Dec 34 6 1102 1104 10.1111/j.1528-1157.1993.tb02140.x 8243363 Oles KS Gal P Bioequivalency revisited: Epitol versus tegretol Neurology 1993 Dec 43 12 2435 2436 10.1212/WNL.43.12.2435 8255435