The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
Carnexiv (carbamazepine) is a sodium channel blocker.
Carnexiv is specifically indicated as replacement therapy for oral carbamazepine formulations, when oral administration is temporarily not feasible, in adults with the following seizure types:
- Partial seizures with complex symptomatology
- Generalized tonic-clonic seizures
- Mixed seizure patterns which include the above, or other partial or generalized seizures
Carnevix is supplied as an injection for intravenous administration. The recommended total daily dose is 70% of the total daily dose of oral carbamazepine from which patients are being switched; divide the total daily dose of Carnexiv equally in four infusions separated by 6 hours; dilute each dose of Carnexiv in 100 mL of diluent and infuse intravenously over 30 minutes. Use of Carnexiv is not recommended for periods longer than 7 days.
The FDA approval of Carnexiv was based on bioavailability studies comparing oral carbamazepine to Carnexiv. Following adjustment of the intravenous dose by the 70% conversion factor, daily plasma exposures of carbamazepine following 15-minute or 30-minute infusions every 6 hours were comparable to those observed following oral dosing. The pharmacokinetics of carbamazepine-10,11-epoxide were similar following both intravenous and oral dosing.
Adverse effects associated with the use of Carnexiv may include, but are not limited to, the following:
- blurred vision
- infusion-related reaction
- infusion site pain
Carnexiv comes with a black box warning of serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) and the risk of aplastic anemia and agranulocytosis, following the use of Carnexiv.
Mechanism of Action
Carnexiv (carbamazepine) is a sodium channel blocker. The mechanism by which carbamazepine exerts its anticonvulsant activity is unknown. The principal metabolite of carbamazepine, carbamazepine-10,11-epoxide, has demonstrated anticonvulsant activity in in vivo animal models of seizures. However, its contribution to the therapeutic effect of carbamazepine is unknown.