Korean Journal of Medicine(구 대한내과학회지). Vol. 86 No. 6 (2014) pg. 686, 9 p.
Hyponatremia results from a relative excess of total body water compared with the sodium content. Except for primary polydipsia, vasopressin activation plays a major role in pathogenesis of water retention. Consequently, the increase of solute-free water clearance by inactivating vasopressin action would be a more reasonable therapeutic approach than the addition of sodium. The V2 vasopressin receptor is mainly localized to the collecting ducts in the kidney and causes water reabsorption via water channels. Selective V2 receptor antagonists or vaptans were recently introduced to clinical practices and may be useful for correcting dilutional hyponatremia. Clinical trials have shown that vaptans are effective in increasing the serum sodium concentration in patients with syndrome of inappropriate anti-diuresis and congestive heart failure and that they might be safe as long as patients are allowed free accesses to water. However, the indications for using vaptans need to be more refined, and the question of their long-term cost-effectiveness should be answered. In addition, the potential roles of vaptans in ameliorating the growth of cysts in polycystic kidney disease, saving diuretics in edematous disorders, and retarding the progression of chronic kidney disease are being explored. (Korean J Med 2013;85:686-694)