BACKGROUND: According to the National Institutes of Health, more than 350,000 people in the United States receive treatment for kidney failure, or end-stage renal disease each year. About 60 percent of patients undergo hemodialysis, a process that removes wastes and excess fluid from the bloodstream by passing it through a membrane in an artificial kidney machine. Although regular hemodialysis treatment helps maintain life, studies show it provides only about a tenth of the cleaning function of normal kidneys.
DIALYSIS COMPLICATIONS: One of the problems with hemodialysis is that it does not do an adequate job of removing phosphorus from the blood. Elevated phosphorus levels in the blood can trigger hyperparathyroidism, a condition that may lead to serious bone and cardiovascular problems. Research indicates a buildup of calcium in coronary blood vessels can lead to an increased risk for cardiac death. Research has also shown that elevated phosphorus levels in the blood is an independent risk factor for mortality among kidney patients on hemodialysis.
Many patients on dialysis take medications that bind dietary phosphorus, thereby allowing its excretion in the stool rather than its absorption by the body. Traditional binding agents include calcium carbonate (a main ingredient in popular stomach relievers) and calcium acetate. However, some patients using these calcium-based binders develop high calcium levels, which can contribute to cardiovascular disease.
A BETTER WAY: Now, scientists are looking at non-calcium-based binders as a way to get phosphorus out of the body without increasing calcium to dangerous levels. One drug currently being tested is lanthanum carbonate (Fosrenol), developed by Shire Pharmaceuticals Group, PLC, in the United Kingdom. It is not yet approved for use in the United States.
A recent study, which was part of the FDA approval process at the University of North Carolina at Chapel Hill, showed a 50-percent reduction in the number of deaths among kidney hemodialysis patients who were given Fosrenol to prevent excess phosphorus from accumulating in the bloodstream. Researchers found it to be well-tolerated by patients. Patients also found it easier to take because it is chewable and does not require a lot of fluid to swallow. Excess fluid build up is a problem for dialysis patients. UNC-CH researchers believe Fosrenol will become the preferred phosphate binder for dialysis patients. FDA approval of Fosrenol may occur as soon as March 2003.
FOR MORE INFORMATION, PLEASE CONTACT:
National Kidney Foundation
30 East 33rd St.
New York, NY 10016