Fluid retention and cardiomegaly associated with carbamazepine in an epileptic child.

Carbamazepine (CBZ) has been reported to have an antidiuretic action, though it is not known how it produces this effect. This is a well recognized complication of CBZ therapy in adults. However this syndrome has been rarely observed in childhood. We present an epileptic child with fluid overload due to CBZ treatment who was referred with chest pain and cardiomegaly. Our patient developed fluid retention with cardiomegaly during treatment with CBZ alone at a normal dose and for a short time. To our knowledge this is the first case of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) due to CBZ therapy which has been observed to be associated with cardiomegaly.