ATC code: B03AC02 (Iron, parenteral preparations).
Pharmacology: Pharmacodynamics: Following intravenous administration of iron (III) hydroxide sucrose complex injection, iron (III) hydroxide sucrose is dissociated by the reticulo-endothelial system into iron and sucrose leading to increases in serum iron and serum ferritin and decrease in total iron binding.
Pharmacokinetics: The following data are based on the innovator product (Venofer 20mg iron/ml, solution for injection or concentrate for solution for in.fusion) summary of product characteristics from UK.
Following intravenous injection of a single dose of Iron (III) hydroxide Sucrose Injection containing 100 mg iron, maximum iron levels, averaging 538 μmol/i were obtained 10 minutes after injection. The volume of distribution of the central compartment corresponded well to the volume of plasma (approximately 3 litres).
The iron injected was rapidly cleared from the plasma, the terminal half-life being approx. 6 h. The volume of distribution at steady state was about 8 litres, indicating a low iron distribution in the body fluid. Due to the lower stability of iron (III) hydroxide sucrose in comparison to transferrin, a competitive exchange of iron to transferrin was observed. This resulted in iron transport of approx. 31 mg iron/24 h.
Renal elimination of iron, occurring in the first 4 h after injection, corresponds to less than 5% of the total body clearance. After 24 h the plasma levels of iron were reduced to the pre-dose iron level and about 75% of the dosage of sucrose was excreted.
The ferrokinetics of Iron (III)-hydroxide sucrose complex injection labelled with 59Fe and 52Fe were assessed in 5 patients with anaemia and chronic renal failure. Plasma clearance of 52Fe was in the range of 60 to 100 minutes. 52Fe was distributed to the liver, spleen and bone marrow. At two weeks after administration, the maximum red blood cell utilisation of 59Fe ranged from 62% to 97%.
The polynuclear iron(III)-hydroxide cores are superficially surrounded by a large number of non-covalently bound sucrose molecules resulting in a complex whose molecular mass Mw is approx. 43 kDa. This is sufficiently large to prohibit renal elimination. The resulting complex is stable and does not release ionic iron under physiological conditions. The iron in the polynuclear cores is bound in a similar structure as in the case of physiologically occurring ferritin.