Efficacy and safety of oral conivaptan: a V1A/V2 vasopressin receptor antagonist, assessed in a randomized, placebo-controlled trial in patients with euvolemic or hypervolemic hyponatremia

J Clin Endocrinol Metab. 2006 Jun;91(6):2145-52. doi: 10.1210/jc.2005-2287. Epub 2006 Mar 7.


Context: Hyponatremia [serum sodium concentration ([Na(+)]), <135 mEq/liter] is the most common fluid and electrolyte abnormality among hospitalized patients. It is frequently caused by the inappropriate release of arginine vasopressin.

Objective: The objective of this study was to evaluate the efficacy and safety of oral conivaptan, a vasopressin V(1A)/V(2) receptor antagonist, in patients with euvolemic or hypervolemic hyponatremia.

Design: The study design was a 5-d placebo-controlled, randomized, double-blind study.

Setting: The study was performed at a hospital.

Intervention: Oral conivaptan (40 or 80 mg/d) or placebo was given in two divided doses.

Patients: Seventy-four patients (average baseline serum [Na(+)], 115 to <130 mEq/liter) were studied.

Main outcome measure: The main outcome measure was the change from baseline in serum [Na(+)] area under the curve.

Results: The least-squares mean change from baseline in the serum [Na(+)] area under the curve with conivaptan (40 and 80 mg/d) was 2.0-fold (P = 0.03) and 2.5-fold (P < 0.001) greater, respectively, than that with placebo. The median time to achieve a confirmed increase in serum [Na(+)] of 4 mEq/liter or more from baseline was 71.7 h for placebo, 27.5 h for 40 mg/d conivaptan (P = 0.044), and 12.1 h for 80 mg/d conivaptan (P = 0.002). The mean total times during which patients had a serum [Na(+)] level of 4 mEq/liter or more above baseline were 46.5, 69.8, and 88.8 h (P = 0.001), respectively. The least-squares mean change in serum [Na(+)] from baseline to end of treatment was 3.4 mEq/liter for placebo, 6.4 mEq/liter for 40 mg/d conivaptan, and 8.2 mEq/liter for 80 mg/d conivaptan (P = 0.002). A confirmed normal serum [Na(+)] (>/=135 mEq/liter) or increase of 6 mEq/liter or more was observed in 48% of patients given placebo, 71% given 40 mg/d conivaptan, and 82% given 80 mg/d conivaptan (P = 0.014). Headache, hypotension, nausea, constipation, and postural hypotension were the most common adverse events.

Conclusion: Oral conivaptan (40 and 80 mg/d) was well tolerated and efficacious in correcting serum [Na(+)] in hyponatremia.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Antidiuretic Hormone Receptor Antagonists*
  • Arginine Vasopressin / blood
  • Benzazepines / adverse effects
  • Benzazepines / therapeutic use*
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme Inhibitors
  • Double-Blind Method
  • Female
  • Humans
  • Hyponatremia / blood
  • Hyponatremia / drug therapy*
  • Male
  • Sodium / blood


  • Antidiuretic Hormone Receptor Antagonists
  • Benzazepines
  • Cytochrome P-450 Enzyme Inhibitors
  • conivaptan
  • Arginine Vasopressin
  • Sodium
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human