Carboxamides
Oxcarbazepine, a carboxamide, is chemically similar
to carba-mazepine but causes less induction of hepatic enzymes. Oxcar-bazepine
is a prodrug. It’s useful as adjunctive therapy or monotherapy for adults with
partial seizures and as adjunctive therapy for children with partial seizures.
Oxcarbazepine is completely absorbed and
extensively metabo-lized by hepatic enzymes to the 10-monohydroxy metabolite
(MHD) that’s responsible for its pharmacologic activity. MHD is excreted
primarily by the kidneys.
The half-life of MHD is about 9 hours. Unlike
carbamazepine, ox-carbazepine doesn’t induce its own metabolism.
The precise mechanism of action of oxcarbazepine
and its metabolite MHD is unknown, but antiseizure activity is thought to occur
through blockade of sodium-sensitive channels, which pre-vents seizure spread
in the brain.
Oxcarbazepine is FDA-approved as adjunctive therapy
for partial seizures in adults and children older than age 4 and as
monothera-py for adults.
As with carbamazepine, it’s also effective for
generalized seizures but may worsen myoclonic and absence seizures.
Carbamazepine, phenytoin, phenobarbital, valproic
acid, and ve-rapamil may decrease the levels of oxcarbazepine’s active
metabolite MHD.
·
Oxcarbazepine may decrease the effectiveness of hormonal contraceptives
and felodipine.
·
Dosage reductions are
necessary for patients with renal impairment (creatinine clearance less than 30
ml/minute) and those at risk for renal impairment, such as elderly patients.
(See Adverse reactions to oxcar-bazepine.)
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.