What is the recommended dose of iron sucrose (intravenous iron) for treating iron deficiency anemia?

Iron Sucrose Dosing for Iron Deficiency Anemia

The recommended dose of iron sucrose is 200 mg intravenously per infusion, administered 2-3 times weekly, with a maximum single dose of 200 mg and maximum weekly dose of 500 mg, for a total cumulative dose of 1000-2000 mg based on body weight and hemoglobin level. 1, 2

Standard Dosing Protocol

Total Dose Calculation Based on Clinical Parameters

For patients with hemoglobin 10-12 g/dL (women) or 10-13 g/dL (men):

• Body weight <70 kg: 1000 mg total dose 2
• Body weight ≥70 kg: 1500 mg total dose 1, 2

For patients with hemoglobin 7-10 g/dL:

• Body weight ≥70 kg: 2000 mg total dose 1, 2

Administration Schedule

• Individual dose: 200 mg per infusion (maximum single dose) 1, 2
• Frequency: 2-3 times weekly 1
• Maximum weekly dose: 500 mg 2
• Infusion time: Administer over minimum 30 minutes 1

The American Society of Clinical Oncology specifically recommends this 200 mg per infusion protocol, which translates to 5-10 infusions to reach the total calculated dose 1. In clinical practice, this means patients typically receive iron sucrose twice weekly for 2.5-5 weeks depending on their total iron deficit 3, 4.

Preparation and Administration Guidelines

Dilution protocol:

• Dilute in 0.9% normal saline 2
• Maximum concentration: 1-2 mg/mL for doses up to 200 mg 2
• Maximum volume: 250 mL for doses of 300-500 mg 2

Infusion technique:

• Start slowly over the first 5 minutes to monitor for reactions 2
• No test dose is required for iron sucrose, unlike iron dextran 1, 2
• However, consider a 25 mg test dose in patients with history of IV iron sensitivities or multiple drug allergies 2

This represents a significant safety advantage over iron dextran preparations, which carry higher anaphylaxis risk and require mandatory test dosing 1.

Monitoring and Expected Response

Baseline assessment:

• Confirm iron deficiency with transferrin saturation <20% and ferritin <100 ng/mL 1
• Document baseline hemoglobin, ferritin, and transferrin saturation 2

Follow-up monitoring:

• Recheck hemoglobin at 3-4 weeks post-infusion 2
• Target response: Hemoglobin increase of at least 2 g/dL within 4 weeks 1, 2
• Do not evaluate iron parameters within 4 weeks of administration, as circulating iron interferes with assay results 1, 2

Clinical trials demonstrate mean hemoglobin increases of 3.29 g/dL in women and 4.58 g/dL in men, with 84-94% of patients achieving the target 2 g/dL rise 4.

Special Population: Dialysis Patients

Hemodialysis-dependent patients:

• Administer 100-300 mg weekly during induction phase 1
• Total induction dose: 1000-1200 mg 1
• Maintenance dosing: 2 mg/kg once or twice monthly 1
• Can be administered directly into the dialysis line 3

The dialysis population has the most extensive safety data, with iron sucrose used for over 50 years internationally and demonstrating excellent tolerability when administered as 100 mg IV push over 5 minutes without test dose 3.

Safety Profile and Adverse Effects

Common side effects (generally mild to moderate):

• Hypotension, nausea, vomiting, diarrhea 2
• Flushing, abdominal cramps 2
• Arthralgias/myalgias 2

Serious reactions:

• Hypersensitivity reactions: approximately 0.5% of patients 2
• Anaphylaxis: exceedingly rare (<1:200,000 administrations) 1, 2
• Hypophosphatemia: Only 1% with iron sucrose (compared to 58% with ferric carboxymaltose) 5, 2

This low hypophosphatemia rate is a distinct advantage of iron sucrose over newer formulations like ferric carboxymaltose, particularly important for patients requiring repeat infusions 5, 2.

Critical Safety Considerations and Contraindications

Absolute contraindications:

• Active bacteremia (defer treatment until resolved) 2
• Hemoglobin >15 g/dL 5
• Evidence of iron overload 1

Maximum dose limits (do not exceed):

• Single dose: 200 mg 2
• Weekly dose: 500 mg 2

Exceeding these limits increases risk of dose-related anaphylactoid reactions 2. Maintain transferrin saturation below 50% and serum ferritin below 800 μg/L to avoid iron overload 1.

Clinical Indications for IV Iron Sucrose Over Oral Iron

First-line IV iron is recommended for:

• Clinically active inflammatory bowel disease 1
• Previous intolerance to oral iron 1
• Hemoglobin <10 g/dL requiring rapid correction 1
• Patients requiring erythropoiesis-stimulating agents 1
• Chronic kidney disease on dialysis 1, 3

Oral iron may be reserved for patients with mild anemia, clinically inactive disease, and no prior oral iron intolerance 1. In inflammatory bowel disease specifically, hepcidin activation from chronic inflammation impairs oral iron absorption, making IV administration more effective 6.

Practical Advantages and Limitations

Advantages:

• No test dose required 1, 2
• Lowest hypophosphatemia risk among IV iron formulations 5, 2
• Extensive safety data across all age groups 3, 7
• Can be administered through dialysis line 3

Limitations:

• Requires multiple clinic visits (5-10 infusions) 1
• Maximum 200 mg per dose limits rapid repletion 2
• More visits compared to ferric carboxymaltose (4-7 visits vs 1-2) 5

For patients requiring rapid iron repletion or those with limited clinic access, ferric carboxymaltose (1000 mg single dose) may be preferred despite higher cost and hypophosphatemia risk 5, 8.