title: Vaptans are not the mainstay of treatment in hyponatremia: perhaps not yet.
abstract: Two vasopressin antagonists ('vaptans') are now in the market for the treatment of euvolemic (Europe) or euvolemic and hypervolemic (United States) hyponatremia: conivaptan for intravenous use and tolvaptan for oral application. Although their specificity and effectiveness are considered established, their indications are not. At present, we do not know which symptoms of hyponatremia and which degree of hyponatremia should serve as indications for vaptans. Other areas of uncertainty relate to the following unanswered questions: do vaptans shorten the duration of hospitalization? Is it justifiable to use them to prevent relapse of hyponatremia in (chronic) SIAD(H)? (In this text we use the abbreviation SIAD(H) instead of the recently proposed abbreviation SIAD to emphasize that vaptans will work only in the presence of ADH ('SIADH') but not in the syndrome of nephrogenic antidiuresis.) Do they decrease the high mortality associated with hyponatremia? How do we justify the cost of chronic vaptan therapy? The optimal vaptan regimen (dose, timing of controls) to treat SIAD(H) is currently not established, as is the procedure to be recommended in a too rapid correction rate of (chronic) hyponatremia. Until these requirements shall be met by additional studies, we are hesitant to consider vaptans a treatment of choice for the appropriate hyponatremias.
authors: Division of Nephrology, Department of Medicine III, Universitätsklinikum C. G. Carus, Fetscherstrasse 74, Dresden, Germany. peter.gross@uniklinikum-dresden.de
authors: Peter A
authors: PA
authors: Gross
authors: Andrea
authors: A
authors: Wagner
authors: Guy
authors: G
authors: Decaux
mesh_terms: D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines / Q000191:economics / Q000627:therapeutic use; D016527:Drug Costs; D006801:Humans; D007010:Hyponatremia / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control; D007177:Inappropriate ADH Syndrome / Q000150:complications / Q000188:drug therapy; D000077602:Tolvaptan
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines; C106389:conivaptan; D000077602:Tolvaptan