Intravenous carbamazepine: a new formulation of a familiar drug.

INTRODUCTION: Oral carbamazepine (CBZ), a broad-spectrum antiseizure drug (ASD) widely used for over 50 years, remains an important treatment choice for focal (partial) epilepsy. Although CBZ is a known inducer of cytochrome P450 (CYP) isoenzymes, many prescribers fail to recognize the potential issues with CBZ induction and are therefore unaware of the risk of drug toxicity upon CBZ withdrawal. Areas covered: Managing concomitant medications in CBZ-treated patients can be difficult. Abruptly stopping CBZ treatment, as may occur when patients are unable to take oral medication, can affect plasma concentrations of other medications. An intravenous (IV) formulation of CBZ has been recently approved by the US FDA for short-term replacement therapy in patients with focal and generalized seizures. Use of IV CBZ allows maintenance of stable plasma concentrations in circumstances when oral administration is temporarily impractical. Expert commentary: CBZ remains a frequently used treatment for focal seizures. With knowledge of the potential issues related to de-induction upon CBZ withdrawal, continuity of care with IV CBZ is an important step in improving the overall care of CBZ-treated patients.