[SIADH with epileptic seizures and coma in fluoxetine therapy]

Hyponatremia and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) have been associated with several psychotropic drugs e.g., carbamazepine, neuroleptics, tricyclic antidepressants and more recently selective serotonin reuptake inhibiting (SSRI) antidepressants. SSRIs have gained widespread use in elderly depressed patients because of their favourable adverse effect profile. However, SSRIs have recently been associated increasingly with SIADH. We describe a 82-year old patient who was hospitalised after witnessed convulsions ten days after initiation of fluoxetine therapy for depression. She had hyponatremia and increased urine osmolarity suggesting SIADH. Using this case we discuss the clinical symptoms, aetiology, differential diagnosis and therapy of drug-induced SIADH.