Abstract and Introduction
A prevalent complication of chronic kidney disease (CKD), especially in dialysis patients, iron deficiency anemia (IDA) continues to be underdiagnosed and undertreated. The main causes of IDA in this population are reduced intake and impaired intestinal absorption of dietary iron, blood losses, chronic inflammation, and increased iron requirements during therapy with erythropoiesis-stimulating agents (ESAs). The addition of IV iron can relieve iron-restricted erythropoiesis and improve ESA response, as well as balance the risks of ESA therapy. Clinical guidelines for anemia of CKD include recommendations for the use of IV iron. There are a number of factors to consider when managing anemia of CKD, and the various forms of iron are not identical.
A prevalent complication of chronic kidney disease (CKD), particularly in dialysis patients, iron deficiency anemia (IDA) remains underdiagnosed and undertreated. This article presents an update on the diagnosis of IDA and the management of IDA with various forms of IV iron.
The World Health Organization defines anemia as a hemoglobin (Hgb) level of <13 g/dL in men and <12 g/dL in women. In the United States, iron deficiency is the most common cause of anemia. A deficiency of iron in RBCs reduces tissue oxygen delivery, increases cardiac output, and may result in ventricular dilation and hypertrophy, if left untreated. The main causes of iron deficiency are increased demand for iron, iron loss, and—frequently the case in CKD—decreased iron stores, reduced iron absorption, or inflammatory iron block.
Anemia of CKD may be due to insufficient production of erythropoietin by diseased kidneys, diminished RBC survival, iron or vitamin deficiencies, bleeding diathesis, hyperparathyroidism, chronic inflammation, or comorbidities.[2,3] Iron deficiency also can develop in hemodialysis (HD) patients receiving erythropoiesis-stimulating agents (ESAs), which cause an increased demand for iron; blood loss from dialysis is another cause of iron deficiency. Diabetic patients are at increased risk for anemia, and anemia itself is an independent risk factor for CKD.[5,6]
Symptoms of iron deficiency include fatigue, weakness, anorexia, insomnia, angina, tachycardia, dyspnea, decreased mental and physical performance, and possibly heart failure. Although anemia correction in CKD has been shown to slow the progression of renal disease and improve overall quality of life, IDA remains underdiagnosed and undertreated.[2,7,8]
Because both early-stage CKD and anemia are usually asymptomatic, renal and hematologic laboratory values should be monitored annually in patients at risk.[2,3,8] As glomerular filtration rate (GFR) decreases with progressive CKD, the risk of anemia increases from approximately 27% in stage 1 CKD to 76% in stage 5 (GFR <15 mL/min).[5,9]
US Pharmacist. 2013;38(8):22-26. © 2013 Jobson Publishing