Expected Increase in Iron Levels After a Single 200mg Venofer Dose
A single 200mg IV dose of Venofer (iron sucrose) will increase serum ferritin by approximately 288 ng/mL and hemoglobin by 0.9-1.4 g/dL over 4-6 weeks, with the magnitude of response depending on baseline iron stores. 1
Pharmacokinetic Profile
The iron component of Venofer exhibits first-order kinetics with an elimination half-life of 6 hours and distributes mainly in blood (steady-state volume of distribution 7.9 L), with significant amounts reaching the liver, spleen, and bone marrow. 2 Following IV administration, iron sucrose dissociates into iron and sucrose, with the iron transported as a complex with transferrin to erythroid precursor cells where it is incorporated into hemoglobin. 2
Expected Changes in Iron Parameters
Serum Ferritin Response
- Patients receiving 5 weekly doses of 200mg (total 1000mg) showed a mean ferritin increase of 288 ng/mL compared to essentially no change (-5.1 ng/mL) with oral iron. 1
- For a single 200mg dose, expect approximately one-fifth of this effect, or roughly 50-60 ng/mL increase in ferritin. 1
Hemoglobin Response
- In CKD patients with baseline ferritin <100 ng/mL receiving 5 weekly 200mg doses, hemoglobin increased by 1.4 g/dL, compared to 0.9 g/dL with oral iron. 1
- A single 200mg dose would contribute approximately 0.25-0.3 g/dL hemoglobin increase over several weeks. 3, 1
Transferrin Saturation
- Significant increases in serum iron and decreases in total iron binding capacity occur within 4 weeks of initiating iron sucrose treatment at 100mg three times weekly. 2
- A 200mg dose will acutely increase transferrin saturation, though the magnitude varies based on baseline transferrin levels. 4
Critical Timing Considerations for Accurate Assessment
You cannot accurately assess iron parameters immediately after a 200mg dose—wait at least 7 days before checking labs. 5 The guidelines specifically state that accurate assessment of iron parameters after IV infusion of 200-500mg may require an interval of 7 or more days. 5 This is because the iron initially enters an exchangeable compartment before being incorporated into storage and functional pools. 5
Factors Affecting Response Magnitude
Baseline Iron Status
- Patients with lower baseline ferritin (<100 ng/mL) show greater hemoglobin responses to IV iron supplementation. 1
- Free iron may occur if 100mg is administered when transferrin levels are less than 180 mg/dL, suggesting saturation of binding capacity. 4
Concurrent Erythropoietin Therapy
- The combination of low-dose EPO with IV iron produces additive effects, with 80% of patients showing Hct increases ≥3% compared to 48.9% with iron alone. 3
- Without EPO, one-third of predialysis CKD patients maintained target Hct with IV iron alone during maintenance therapy. 3
Clinical Efficacy Benchmarks
After 5 weekly doses of 200mg (1000mg total):
- 54.2% of patients achieved hemoglobin >11.0 g/dL compared to 31.3% with oral iron. 1
- 62.5% met combined hemoglobin/ferritin endpoints versus 0% with oral iron. 1
- 43.8% met all three criteria (hemoglobin/ferritin/TSAT) versus 0% with oral iron. 1
Important Caveats
The 200mg dose represents the maximum single dose approved for iron sucrose, and doses larger than this are not recommended by guidelines. 5, 6 While the response to a single dose is modest, the cumulative effect of serial dosing produces clinically meaningful improvements in both iron stores and hemoglobin levels over 4-6 weeks. 3, 1
The actual clinical response depends heavily on ongoing iron losses (particularly in hemodialysis patients), baseline iron stores, concurrent EPO use, and underlying inflammatory states that may affect iron utilization. 3, 1