The study involved 42 patients with class II or class III congestive heart failure, meaning they experienced mild to marked limitation of activity and were generally able to engage in only mild exertion. Of those, 30 patients took varying doses of lixivaptan and 12 patients received a placebo.
At every dose but the lowest (10 milligrams), lixivaptan produced a significant increase in urine volume over four hours when compared to placebo, and over 24 hours, the output ranged from 1.8 liters in the placebo group to 3.9 liters in patients receiving 400 milligrams of lixivaptan. In addition, lixivaptan dramatically increased solute-free water excretion meaning the urine from patients taking the drug removed more water than sodium from the body.
The apparent effectiveness of the drug not only holds promise as a new treatment for heart failure patients, but also helps clarify the role vasopressin appears to play in the water retention and low sodium concentration in the first place, Abraham said. He and colleagues suggested that a vasopressin antagonist may also be useful in treating hyponatremia that occurs in heart failure patients who are not taking diuretics but who still experience its effects because of an imbalance of water and salt.
About 90 percent of hospitalizations associated with heart failure are related to water retention. Congestive heart failure affects an estimated 5 million Americans, and is characterized by a reduced ejection fraction a measurement of how well the heart is squeezing and often by this seepage of fluid into the lungs, feet, legs or abdominal cavity.
'"/>
Contact: Emily Caldwell
emily.caldwell@osumc.edu
614-293-3737
Ohio State University Medical Center
2-May-2006