Phosphate binders

Abstract

When we stated that sevelamer had not demonstrated superiority over calcium products in clinical trials, we were not implying possible equivalency. We agree that the data from the CARE trial show sevelamer has inferior phosphate-binding capacity compared with calcium acetate. The clinical trial data comparing seve-lamer and calcium products are equivocal. Although four of the studies listed in our Table 3 are limited by study design, the CARE trial also has limitations. The sample size in the CARE trial was small, and the study duration was short. For these reasons, a confirmatory trial showing the superiority of calcium acetate over sevelamer is desirable. The point raised by Dr. Haight and colleagues regarding hypocalcemia is well-taken, and we agree that this deserved greater mention in our review. The National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines have limitations, including a lack of cost information. To our knowledge, there are no published pharmacoeconomic analyses comparing the cost of using sevelamer and calcium. One would think that the calcium products would be less expensive, but the costs provided by Dr. Haight et al. are average wholesale prices, which usually bear little resemblance to actual acquisition costs.