[Diagnostics and new treatment methods of syndrome of inappropriate antidiuretic hormone secretion (SIADH)].

New treatment methods of syndrome of inappropriate antidiuretic hormone secretion (SIADH) has emerged with the oral vasopressin V2-receptor antagonist (VV2RA) tolvaptan, but its therapeutic window remains to be defined. We present the scientific data and describe treatment possibilities of SIADH while raising the questions: "Does the present evidence enable us to identify who to treat with VV2RAs?" and "is VV2RAs justified as first-line treatment?".