New Heart Failure Therapy on Horizon
Drug eases fluid buildup without taxing kidneys
MONDAY, Nov. 10, 2003 (HealthDayNews) -- People with congestive heart failure may soon have an alternative to the usual treatment to suppress the buildup of fluid that starves them of breath.
Heart failure patients who took the new drug, tolvaptan, lost more weight and felt better than those who didn't get the pill, a new study finds. Most of the weight loss was due to a decrease in the fluid that accumulates in people with heart failure, the researchers say.
"The addition of tolvaptan [to heart failure therapy] reduced body weight, mainly by relieving congestion, and made [patients] feel better," says study leader Dr. Mihai Gheorghiade, associate chief of cardiology at Northwestern University's Feinberg School of Medicine in Chicago.
The effects of the drug appeared within 24 hours of starting treatment, the researchers say. The regimen called for a single pill, of varying dosage, for seven weeks after patients were discharged from the hospital.
With 319 patients, the trial wasn't large enough to detect any increase in near-term survival from the drug. However, Gheorghiade says tolvaptan appears to reduce the number of return hospitalizations and deaths within 60 days of being admitted to the hospital with heart failure. The drug is now being tested in 3,600 men and women participating in an international study to see if it indeed saves lives.
Tolvaptan is being developed by Otsuka Maryland Research Institute Inc., which funded the latest research. The drug has yet to be approved for use in people. Gheorghiade, who has been a paid consultant for Otsuka, presented the latest findings Nov. 10 at the American Heart Association annual conference in Orlando, Fla.
Roughly 1 million Americans are hospitalized each year with congestive heart failure. Doctors treat patients from two angles: drugs to improve the efficiency of their heart and diuretics to dry them up.
Although diuretics are often effective, about a quarter of patients are back in the hospital within 60 days for more treatment, and one in 10 are dead. Diuretics also can lead to kidney problems and dangerous imbalances in blood levels of sodium.
Tolvaptan reduces fluid buildup, but it works differently from diuretics. The drug impedes the action of proteins in the kidney called vasopressin V2 receptors. These molecules respond to the hormone vasopressin, which signals cells to take up water. Blocking V2 receptors prevents fluid from accumulating.
In addition to keeping patients on the dry side, tolvaptan also appears to stabilize salt imbalances, or hyponatremia, Gheorghiade says. Hyponatremia is an important predictor of poor outcomes in heart failure patients. To date, he adds, doctors have no drugs to treat this condition -- a fact that could hasten the arrival of tolvaptan.