Comparison of two doses and dosing regimens of tolvaptan in congestive heart failure

J Cardiovasc Pharmacol. 2005 Nov;46(5):609-14. doi: 10.1097/01.fjc.0000180899.24865.b6.

Abstract

Fluid retention and extracellular volume expansion are frequently encountered complications of congestive heart failure (HF) that can cause morbidity and mortality. Tolvaptan (Otsuka) is an orally administered nonpeptide vasopressin (VP) V2 receptor antagonist that inhibits water reabsorption in the kidney by competitively blocking VP binding, resulting in water diuresis without significantly changing total electrolyte excretion. In the 24-hour period following a 30-mg dose of tolvaptan, urine excretion rate increases and declines as plasma concentrations rise and fall; this uneven effect results in 80% of daily urine output in the first 12 hours. Therefore, the current study was designed to assess the pharmacodynamic effects, pharmacokinetics, and clinical safety of tolvaptan 30 mg QD plus placebo versus 15 mg BID over 7 days in patients with NYHA Class II/III heart failure and persistent fluid overload, SBP > or = 90 mm Hg, and a serum creatinine < or = 3.0 mg/dL. Patients were withdrawn from diuretics for 48 hours before randomization. Statistics were performed with ANCOVA for continuous variables and Mantel-Haenszel mean score test stratified by center for categorical variables. Thirty-nine of 40 patients completed days 1 and 7. There were no significant clinical, pharmacokinetic, or pharmacodynamic differences between the dosing regimens over time. Based on these findings, tolvaptan 30 mg was chosen as the comparator for placebo in a large phase 3 survival trial.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Antidiuretic Hormone Receptor Antagonists*
  • Benzazepines / administration & dosage
  • Benzazepines / adverse effects
  • Benzazepines / pharmacokinetics
  • Benzazepines / therapeutic use*
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Heart Failure / drug therapy*
  • Heart Failure / metabolism
  • Humans
  • Male
  • Middle Aged
  • Tolvaptan
  • Treatment Outcome

Substances

  • Antidiuretic Hormone Receptor Antagonists
  • Benzazepines
  • Tolvaptan