title: Serum and urine responses to the aquaretic agent tolvaptan in hospitalized hyponatremic patients.
abstract: Tolvaptan, an oral, selective arginine vasopressin (AVP) V2 receptor antagonist has been approved for the treatment of euvolemic and hypervolemic hyponatremia in the United States. This report summarizes our center's experience with thirteen patients treated for hyponatremia with one 15-mg dose of tolvaptan. The patients had euvolemic or hypervolemic hyponatremia with decreased serum osmolality and serum sodium (SNa) levels less than 129 mEq/L. Eight patients had a diagnosis of the syndrome of inappropriate antidiuretic hormone (SIADH), and five patients had a diagnosis of congestive heart failure (CHF). Results revealed an increase in SNa in all patients from 122.5 ± 4.2 to 128.9 ± 4.1 mEq/L (P < 0.05). The mean increase in SNa of 6.4 mEq/L (range 2-10 mEq/L) 24 h post-tolvaptan was not different in the two groups of patients, but SIADH patients had higher pre and post-tolvaptan SNa levels than CHF patients. Urine osmolalities (UOsm) decreased in all patients, and the patients with SIADH had significantly higher baseline UOsm and a larger decrease in UOsm 12 h post-tolvaptan administration when compared with the CHF patients. AVP levels did not change post-tolvaptan administration. However, the magnitude of increase in SNa levels was inversely related to pretolvaptan AVP levels in the SIADH subgroup (r = -0.7, P = 0.01). Three SIADH patients received small amounts of D5W to attenuate changes in SNa. No significant changes in mean arterial pressure, serum potassium, serum glucose, and blood urea nitrogen or serum creatinine were observed. The data show that tolvaptan is effective for the treatment of hyponatremia and may produce differing responses in disparate patient groups.
authors: Division of Nephrology, Department of Medicine, Lenox Hill Hospital, 100 East 77th Street, New York, NY 10075, USA.
authors: Rick P
authors: RP
authors: Vaghasiya
authors: Maria V
authors: MV
authors: DeVita
authors: Michael F
authors: MF
authors: Michelis
references: Am J Med. 2009 Jul;122(7):679-86
references: 19559171
references: Am J Med. 2006 Jul;119(7 Suppl 1):S47-53
references: 16843085
references: N Engl J Med. 2006 Nov 16;355(20):2099-112
references: 17105757
references: JAMA. 2007 Mar 28;297(12):1332-43
references: 17384438
references: Arch Intern Med. 2010 Feb 8;170(3):294-302
references: 20142578
references: Kidney Int. 2009 Sep;76(6):587-9
references: 19721422
references: Am J Cardiol. 2006 Apr 1;97(7):1064-7
references: 16563917
references: Circulation. 2001 Nov 13;104(20):2417-23
references: 11705818
references: Am J Med. 2006 Jul;119(7 Suppl 1):S21-9
references: 16843081
references: Int Urol Nephrol. 2008;40(3):725-30
references: 18363040
references: NDT Plus. 2009 Nov;2(Suppl_3):iii5-iii11
references: 19881934
references: Clin J Am Soc Nephrol. 2007 Nov;2(6):1110-7
references: 17913972
references: NDT Plus. 2009 Nov;2(Suppl_3):iii12-iii19
references: 19881932
references: QJM. 2006 Aug;99(8):505-11
references: 16861720
references: Int Urol Nephrol. 2009;41(3):733-7
references: 19472069
references: Nephrol Dial Transplant. 2006 Jan;21(1):70-6
references: 16141458
references: J Am Geriatr Soc. 2006 Feb;54(2):345-53
references: 16460390
references: Am J Med. 2009 Sep;122(9):857-65
references: 19699382
references: Am J Med. 2006 Jan;119(1):71.e1-8
references: 16431193
references: Clin J Am Soc Nephrol. 2006 Nov;1(6):1154-60
references: 17699341
references: Nephrol Dial Transplant. 2010 May;25(5):1524-31
references: 20064953