Administration of iron-containing drugs in non-dialyzed patients with chronic kidney disease

In the review paper an issue of the administration of iron containing drugs in the treatment of anemia in non-dialyzed patients with chronic kidney disease (CKD) is presented. Iron deficiency in patients with CKD (serum ferritin concentration below 100 ng/ml, transferrin saturation below 20%) occurs in 20–70% of cases. Prevalence of iron deficiency depends on stage of CKD and patients’ gender. Among causes of iron deficiency the following reasons are mentioned: blood loss through gastrointestinal tract (17–18% of patients in pre-dialysis stage show positive results of tests on occult blood), diminished absorption (uremic gastroenteropathy, administration of drugs decreasing iron absorption), decreased delivery of food (anorexia, low protein diet), infections and inflammatory state. In the course of infections and inflammatory states body iron storage may be normal, but its utilization for erythropoesis is deteriorated (functional iron deficiency). Results of randomized controlled studies indicate greater efficiency of intravenous therapy in comparison with oral route of iron administration. In practice, the main route of administration of iron – containing drugs to non-dialyzed patients with CKD remains, however, the oral one (iron sulfate, iron fumarate, hem iron) as more convenient and seldom leading to serious side effects. Intravenous iron therapy (iron dextrose, iron polymaltose, sodium-iron gluconate, iron sucrose) is required for cases with absolute deficiency of this microelement, disturbed intestinal absorption, poor tolerance of oral iron medication or its ineffectiveness from other reasons. Administration of erythropoiesis stimulating agents in predialysis period may require intravenous iron therapy because of enhanced consumption of its stores for erythropoiesis. Attention should be paid to possible nephrotoxic effects of administration of iron containing drugs (transient proteinuria, damage of renal tubules, decrease in glomerular filtration rate).