Pharmacology: Pharmacodynamics: 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 approximately 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.
Mechanism of Action: HEAMOFER 20 is an aqueous complex of poly-nuclear iron (III)-hydroxide in sucrose. Following intravenous administration, Heamofer is dissociated into iron and sucrose and the iron is transported as a complex with transferrin to target cells including erythroid precursor cells. The iron in the precursor cells is incorporated into haemoglobin as the cells mature into red blood cells.
Pharmacokinetics: Following intravenous injection of a single dose of Iron Sucrose Injection containing 100 mg iron in healthy volunteers, maximum iron levels, averaging 538 mmol/l, were obtained 10 min 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 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.