[Altered orientation and aggressiveness in an 89-year-old woman].

An 89-year-old woman with Alzheimer's dementia was admitted because of altered orientation, aggressiveness and inability to take care of herself at home. Her patient history indicated that 14 days ago the battery of the pacemaker had be renewed. During that time the patient suffered from psychomotor alterations. Therefore, melperone had been initiated. Inspection of the urine and laboratory findings pointed towards an acute exacerbation of acute intermittent porphyria as a possible cause of the delirium. After discontinuation of melperone with additional parenteral therapy with physiological fluids, the signs of delirium significantly improved.