General Information

Oxtellar XR is an extended-release, once-daily formulation of oxcarbazepine, a currently approved anti-epileptic drug. Oxcarbazepine produces blockade of voltage-sensitive sodium channels, resulting in stabilization of hyperexcited neural membranes, inhibition of repetitive neuronal firing and diminution of propagation of synaptic impulses. These actions are thought to be important in the prevention of seizure spread in the intact brain.

Oxtellar XR is specifically indicated as adjunctive therapy of partial seizures in adults and in children 6 to 17 years of age.

Mechanism of Action

Side Effects

Adverse events associated with the use of Oxtellar XR may include, but are not limited to, the following:

Dizziness

Somnolence

Headache

Balance disorder

Tremor

Vomiting

Diplopia

Asthenia

Fatigue

Dosing/Administration

Oxtellar XR is supplied as a tablet for oral administration. Oxtellar XR should be administered as a single daily dose taken on an empty stomach (at least one hour before or at least two hours after meals). The tablets should be swallowed whole. The recommended daily dose of Oxtellar XR is as follows:

Adults
1,200 mg to 2,400 mg per day, given once daily. Initiate treatment at a dose of 600 mg per day given once daily for one week. Subsequent dose increases can be made at weekly intervals in 600-mg-per-day increments to achieve the recommended daily dose.

Pediatrics 6 to 17 Years of Age
Initiate treatment at a daily dose of 8 mg/kg to 10 mg/kg once daily, not to exceed 600 mg per day in the first week. Subsequent dose increases can be made at weekly intervals in 8-mg/kg to 10-mg/kg increments once daily, not to exceed 600 mg, to achieve the target maintenance daily dose, based on weight.

Clinical Trial Results

FDA Approval
The FDA approval of Oxtellar XR for the treatment of partial seizures in pediatrics was based on adequate and well-controlled studies of Oxtellar XR in adults, along with clinical trials of immediate-release oxcarbazepine in children, and on pharmacokinetic evaluations of the use of Oxtellar XR in children.

Oxtellar XR Primary Trial
The multicenter, randomized, double-blind, placebo-controlled, three-arm, parallel-group study enrolled 366 adults with refractory partial epilepsy. All subjects had at least three partial seizures per 28 days during an eight-week baseline period, were receiving treatment with at least one to three antiepileptic drugs and were on stable treatment for a minimum of four weeks. The subjects received Oxtellar XR (1200 or 2400 mg/day) or placebo. The treatment period included a four-week titration phase followed by a 12-week maintenance phase. The primary end point of the study was median percentage change from baseline in seizure frequency per 28 days during the treatment period relative to the baseline period. The results are as follows: Oxtellar XR 1,200 mg/day: -38.2 percent (p=0.078), Oxtellar XR 2,400 mg/day: -42.9 percent (p=0.003) and placebo: -28.7 percent.

Immediate-Release Oxcarbazepine Adjunctive Therapy Trials
The effectiveness of immediate-release oxcarbazepine as an adjunctive therapy for partial seizures in adults was demonstrated at doses of 600 mg per day; 1,200mg per day and 2,400mg per day (divided twice daily) in a randomized, double-blind, placebo-controlled trial. All doses resulted in a statistically significant reduction in seizure frequency when compared to placebo (p<0.05).