HDCN Article Review/Hyperlink

Spengler K, Follmann H, Boos K-S, Seidel D, et al

Cross-linked iron dextran is an efficient oral phosphate binder in the rat

Nephrol Dial Transplant (May) 11:808-812 1996

The authors investigated the phosphorus binding properties of iron (III) oxide-hydroxide modified dextran beads in vitro and in normal rats. The maximum binding in an aqueous solution was at pH 2-3 and was temperature dependent. Twelve animals had the binder added to their food in the proportion of 8% by weight. After 2 and 4 weeks the P and Ca levels were not different than controls. However, the renal excretion of P was 15 fold lower in the treated group. The amount of P in the stool was 3 times greater in the treated group. The treated group digested 15% less food than the controls. Histological examination of virtually all organs revealed no abnormality. The authors' calculated that 1 g of the binder would bind about 20 mg of P. They feel that studies in humans are warranted.

Comment: A non-toxic, potent P binder not containing Ca would be of great value in the treatment of secondary hyperparathyroidism in renal failure. The iron dextran beads clearly bind P in the intestine but it appears to be a rather weak binder. One would also worry about the decreased digestion of food with the binder and possible long-term malnutrition. I would imagine that studies in humans have already started. (Jay Delmez, M.D., Washington University at St. Louis, MO)