Oxcarbazepine is an anticonvulsant drug primarily used in the treatment of epilepsy. There is some evidence for oxcarbazepine as a mood-stabilizing agent and thus, it can be used as add-on therapy for bipolar disorder in patients that have failed or are unable to tolerate approved treatments. Common side effects include nausea, vomiting, dizziness, drowsiness, headache, double vision and trouble with walking. Although not common, anaphylaxis may occur. Due to its structural similarities to carbamazepine there is approximately a 25-30% chance of cross-reactivity between the two medications. Oxcarbazepine is marketed as Trileptal by Novartis and available in some countries as a generic drug. There is also an extended-release formation marketed as Oxtellar XR by Supernus Pharmaceuticals.