Clinical recommendations for oxcarbazepine

Oxcarbazepine (OXC) is indicated for treating partial-onset with or without secondary generalized tonic-clonic seizures, in both adults and children aged over 6 years, as monotherapy or adjuvant therapy. Trials data and extensive clinical experience demonstrate generally good tolerability and antiepileptic efficacy similar to carbamazepine (CBZ), sodium valproate or phenytoin. Since the UK launch of OXC in March 2000, UK collaborators have pooled experience to optimize prescribing recommendations for adults. Many patients are successfully managed using the prescribing information recommended titration schedule. However, evolving clinical experience suggests a slower introduction is preferable (e.g. 150 mg day one, then 300 mg daily, increased by 300 mg weekly) both for monotherapy and adjuvant therapy. Overnight 'switch' from CBZ to OXC (using CBZ:OXC ratio of 1:1.5) has been used for patients responsive to CBZ, but with dose-related side-effects. Owing to individual variations in CBZ enzyme autoinduction, however, overnight switching is advised only for those on CBZ < 800 mg daily; otherwise, slower switching is recommended. OXC is not the first choice alternative for patients developing a CBZ rash owing to increased OXC rash rate in CBZ sensitive subjects. Hyponatraemia may be more common (albeit often asymptomatic) than trials data suggest, especially in the elderly. Serum sodium monitoring is unnecessary, however, unless relevant risk factors or pointers exist. Severe haematological dyscrasias have not been reported with OXC. The enzyme inducing interaction of OXC with ethinyloestradiol and levonorgestrel necessitates additional precautions for women using hormonal contraception.