When is iron supplementation indicated in Chronic Kidney Disease (CKD)?

From the Guidelines

Iron supplementation is indicated in chronic kidney disease (CKD) when patients have iron deficiency or when they are receiving erythropoiesis-stimulating agents (ESAs), specifically when serum ferritin is less than 200 ng/mL and transferrin saturation (TSAT) is less than 20%.

Key Considerations

• For pediatric CKD patients with anemia not on iron or ESA therapy, oral iron (or IV iron in CKD HD patients) administration is recommended when TSAT is ≤20% and ferritin is ≤100 ng/ml 1.
• For pediatric CKD patients on ESA therapy who are not receiving iron supplementation, oral iron (or IV iron in CKD HD patients) administration is recommended to maintain TSAT ≥20% and ferritin ≥100 ng/ml 1.
• The choice between oral and intravenous iron supplementation should be based on the severity of iron deficiency, availability of venous access, response to prior oral iron therapy, side effects with prior oral or IV iron therapy, patient compliance, and cost 1.

Administration and Monitoring

• Oral iron supplementation can be given as ferrous sulfate 325 mg (containing 65 mg elemental iron) taken 1-3 times daily between meals.
• Intravenous options include iron sucrose (100-200 mg per dose), ferric gluconate (125-250 mg per dose), or ferric carboxymaltose (750-1000 mg per dose), administered according to individual needs and hemoglobin response.
• Patients should be monitored regularly with complete blood counts and iron studies to assess response and adjust therapy as needed.

Rationale

• Iron supplementation helps correct anemia in CKD by providing the necessary building blocks for red blood cell production, which is often impaired due to reduced erythropoietin production by the kidneys.
• Iron supplementation enhances the effectiveness of ESAs when they are used.
• The evidence suggests that correction of anemia is more likely to occur, and at lower doses of erythropoietin, if the lower limit of serum ferritin is greater than 200 ng/ml and the lower limit of transferrin saturation is greater than 20% 1.

From the FDA Drug Label

Evaluate the iron status in all patients before and during treatment. Administer supplemental iron therapy when serum ferritin is less than 100 mcg/L or when serum transferrin saturation is less than 20%. The majority of patients with CKD will require supplemental iron during the course of ESA therapy.

Iron supplementation is indicated in Chronic Kidney Disease (CKD) when:

• Serum ferritin is less than 100 mcg/L
• Serum transferrin saturation is less than 20% 2 3

From the Research

Indications for Iron Supplementation in CKD

Iron supplementation is indicated in patients with Chronic Kidney Disease (CKD) who have anemia, which is a common complication of CKD 4. The criteria used to define iron deficiency in CKD patients are different from those with normal renal function. Absolute iron deficiency is defined when the transferrin saturation (TSAT) is ≤20% and the serum ferritin concentration is ≤100 ng/mL among predialysis and peritoneal dialysis patients or ≤200 ng/mL among hemodialysis patients 4.

Methods of Iron Supplementation

There are two main methods of iron supplementation: intravenous (i.v.) and oral. i.v. iron supplementation is the preferred method for CKD patients on dialysis (CKD stage 5D), while either i.v. or oral iron is recommended for patients with CKD stages 3-5 4. Oral liposomal iron has emerged as a promising option for non-dialysis CKD patients, with studies showing it to be a safe and effective option for correcting anemia, although with lower efficacy in replenishing iron stores compared to i.v. iron 5, 6.

Benefits and Risks of Iron Supplementation

Iron supplementation has been shown to increase hemoglobin levels and reduce the need for erythropoiesis-stimulating agents (ESAs) in CKD patients 7, 8. However, it also carries risks, such as hypotension and gastrointestinal adverse events 5, 8. The choice of iron supplementation method should be individualized based on the patient's specific needs and medical history.

Key Findings

• Iron supplementation is recommended for all CKD patients with anemia 4.
• i.v. iron supplementation is the preferred method for CKD patients on dialysis (CKD stage 5D) 4.
• Oral liposomal iron is a safe and effective option for non-dialysis CKD patients, although with lower efficacy in replenishing iron stores compared to i.v. iron 5, 6.
• Iron supplementation can increase hemoglobin levels and reduce the need for ESAs in CKD patients 7, 8.