CARBAMAZEPINE AND CORTICOSTEROIDS

The clearance of methylprednisolone and prednisolone is increased in patients taking carbamazepine. Dexamethasone clearance is also increased, and therefore the results of the dexamethasone adrenal suppression test may be invalid in those taking carbamazepine. More study is needed but it is likely that other corticosteroids such as hydrocortisone and prednisone may be affected.
Patients taking carbamazepine are likely to need increased doses of dexametha- sone, methylprednisolone or prednisolone. Prednisolone is less affected than methylprednisolone and is probably preferred.