Aripiprazole-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Aripiprazole is a newer atypical antipsychotic agent used for effective treatment of schizophrenia. It significantly reduces unwanted side effects of older typical antipsychotics by targeting, with high affinity, dopamine D2/D3 and serotonin 5-HT1A/5-HT-2A receptors. Its documented mechanism of action makes it an unlikely agent to cause syndrome of inappropriate antidiuretic hormone secretion (SIADH). We present the first reported case of SIADH caused by aripiprazole in a patient with history of schizophrenia without other precipitating factors to explain hyponatremia or SIADH.