Dose-related side effects
Common side effects of oxcarbazepine include:

• sedation
• dizziness
• double vision
• nausea
• headache

If these problems do not diminish within several days, a reduction in the dose of oxcarbazepine often will solve the problem. Problems with sedation also may be helped by splitting the dose or giving the largest dose at bedtime. Patients taking oxcarbazepine and lamotrigine simultaneously may have fewer side effects if the pills are staggered by 1-2 hours.

Idiosyncratic reactions

Rash
Skin reactions occur less frequently with oxcarbazepine than with carbamazepine. In the Novartis safety database of Trileptal (oxcarbazepine), which includes data on 2,436 patients treated with Trileptal and 277 treated with carbamazepine, 2.8% of Trileptal-treated patients had hypersensitivity reactions compared with 6.5% of those on carbamazepine.

There is cross-sensitivity with skin reactions. In one study, 46 of 55 patients (84%) who were switched from carbamazepine to oxcarbazepine because of skin reactions did not experience a recurrence while taking oxcarbazepine. In another report, 37 of 51 patients (73%) with previous skin reactions to carbamazepine did not have a recurrence with oxcarbazepine.

Abnormal liver or bone marrow function
No clinically relevant fluctuations of white blood count have been observed in clinical studies and clinically relevant elevations of liver function tests appear to occur less often than with carbamazepine. In a large retrospective study, liver and bone marrow function tests became abnormal in no more than 2% of patients.

Reviewed by Steven C. Schachter, MD
Submitted: 01/03/08