Comparison of the metabolism of 2 injectable iron preparations (sorbitol iron and polymaltose iron) with the metabolism of transferrin and hemoglobin iron

: Iron distribution in the different organs and chemical compartments of the rat has been studied after intravenous injection of 59Fe-sorbitol (Jectofer-Astra) and 59Fe-polymaltose (Fer Hausmann Lucien) and compared with the metabolism of 59Fe bound to transferrin and to hemoglobin. Both parenteral iron preparations are utilized more slowly than Iron-transferrin. The speed of red cell incorporation of 59Fe from sorbitol is similar to the hemoglobin iron utilization (half incorporation in red cells: 4 to 5 days). Iron polymaltose is much more slowly utilized (half incorporation in the red cells: 13 to 15 days). One third of the 59Fe from sorbitol is eliminated in urine, the remaining iron being taken up to 60% by the liver and to 30% by the bone marrow. It is very quickly catabolized, since as early as the first hour after injection most of the 59Fe is bound to polymaltose till the 14th day. Between the third and fourth week 25% of the 59Fe from polymaltose is found in hemosiderin. These metabolic differences are also found in man: 59Fe from iron sorbitol is found in urine after injection, is mobilized by desferrioxamine after six days, and eliminated through dialysis membranes. On the other hand the 59Fe from polymaltose is slowly but completely utilized and not mobilized by desferrioxamine in the first week after injection. The data give the indications for use and the pharmacokinetics of two forms of parenteral iron and oral preparations in the treatment of iron deficiency.