Drug reduces risks for dialysis patients

Kidney failure has a knack for depleting calcium in the blood. That can weaken a person’s bones and cause other problems.

To correct for a lack of calcium, roughly half of all kidney dialysis patients get vitamin D injections. Unfortunately, calcitriol–an injected form of vitamin D that physicians have been prescribing for more than 2 decades–sometimes causes calcium and phosphate concentrations in the blood to rise steeply, which can boost heart disease risk. A newer form of injectable vitamin D called paricalcitol gained regulatory approval in 1998 after tests showed it did a better job of stabilizing calcium and phosphate concentrations in kidney-disease patients.

In the first study to compare survival in dialysis patients getting one drug or the other, researchers report that dialysis patients getting paricalcitol live longer than those receiving calcitriol. The study appears in the July 31 New England Journal of Medicine (NEJM).

Researchers examined the records of more than 67,000 dialysis patients with an average age of 61. About half got paricalcitol; the rest got calcitriol. After 3 years, 58.7 percent of those getting paricalcitol had survived, compared with 51.5 percent of those receiving calcitriol, says study coauthor Ravi Thadhani, a nephrologist at Massachusetts General Hospital in Boston.

Writing in the same issue of NEJM, Tilman B. Drüeke of Necker Hospital in Paris and David A. McCarron of the University of California, Davis point out that excess calcium and phosphate in the blood contribute to calcification of soft tissues in the body, including blood vessels, and may explain in part the heightened heart disease risk seen in people with kidney failure.

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