What is the recommended iron formulation, such as iron sucrose, Infed (iron dextran), or Feraheme (ferumoxytol), for a patient requiring iron infusion?

Recommended Iron Formulation and Infusion Orders

For most patients requiring iron infusion, use ferric carboxymaltose (FCM) or low molecular weight iron dextran (LMWID) as first-line agents, as these allow total dose infusion (TDI) of 1000 mg in a single visit, which is more convenient, cost-effective, and reduces cumulative infusion reaction risk compared to iron sucrose or Infed. 1

Formulation Selection Algorithm

First-Line Choices (Total Dose Infusion Capable)

Ferric Carboxymaltose (FCM):

• Preferred for most ambulatory patients due to no test dose requirement and proven efficacy in multiple conditions including heart failure and inflammatory bowel disease 1
• Dose: 750-1000 mg per infusion (up to 20 mg/kg body weight) 1
• Can be delivered within 15 minutes 1
• No test dose required 1

Low Molecular Weight Iron Dextran (LMWID/Infed):

• Cost-effective alternative with ability to give >1000 mg by infusion 1
• Despite black box warning in US (not in Europe), multiple studies demonstrate safety equivalent to other formulations when properly administered 1
• Requires test dose due to FDA labeling, though evidence does not support higher anaphylaxis risk with current low molecular weight formulation 1

Second-Line Choices (Multiple Visits Required)

Iron Sucrose:

• Maximum individual dose limited to 200-300 mg per treatment episode 1
• Requires 4-7 visits for complete iron repletion 1
• Use only when: Patient is already receiving frequent dialysis treatments where multiple visits are not a burden, or patient has documented severe reactions to TDI-capable formulations 1, 2
• No test dose required 1, 3

Ferumoxytol (Feraheme):

• Dose: 510 mg × 2 doses 1
• Important caveat: Interferes with MRI interpretation for 8 weeks post-administration; radiologists must be notified 1
• No test dose required 1

Clinical Context-Specific Recommendations

Inflammatory Bowel Disease

• Intravenous iron is first-line for clinically active IBD, hemoglobin <10 g/dL, previous oral iron intolerance, or need for erythropoiesis-stimulating agents 1
• FCM preferred based on FERGIcor trial showing better efficacy and compliance versus iron sucrose 1
• Dosing by body weight and hemoglobin: 1000-2000 mg total dose depending on severity 1

Chronic Heart Failure

• FCM demonstrated sustained improvement in 6-minute walk test, NYHA class, and quality of life in CONFIRM-HF trial 1
• Treat iron deficiency even without anemia in symptomatic heart failure patients 1

Chronic Kidney Disease

• Any formulation acceptable given frequent dialysis encounters 2
• Iron sucrose historically used: 100 mg IV push over 5 minutes, repeated doses 1, 4
• LMWID can be given as 500-1000 mg infusion for CKD patients not on frequent dialysis 1

Infusion Orders: Step-by-Step Protocol

For Low Molecular Weight Iron Dextran (Infed)

Test Dose (Required):

• Dilute 1000 mg LMWID in 250 mL normal saline 1
• Option 1: Administer 25 mg test dose using syringe filled with diluted solution, inject slowly over 5 minutes 1
• Option 2: Initiate infusion slowly for approximately 5 minutes 1
• Observe for at least 1 hour for reactions 5

Therapeutic Dose:

• If no reaction observed, infuse remaining 975 mg over balance of 1 hour (total infusion time: 1 hour) 1
• Written order: "Iron dextran (Infed) 1000 mg in 250 mL normal saline. Administer 25 mg test dose over 5 minutes, observe 1 hour. If no reaction, infuse remaining dose over 1 hour. Monitor vital signs every 15 minutes during infusion and 30 minutes post-infusion."

For Ferric Carboxymaltose (Injectafer)

No test dose required 1

• Dose: 750-1000 mg depending on body weight and hemoglobin 1
• For body weight <70 kg and Hgb 10-12 g/dL: 1000 mg 1
• For body weight ≥70 kg and Hgb 10-12 g/dL: 1500 mg (give as two separate infusions) 1
• For Hgb 7-10 g/dL: 1500-2000 mg total (give as multiple infusions) 1
• Written order: "Ferric carboxymaltose 750 mg in 250 mL normal saline, infuse over 15 minutes. Monitor vital signs before, during, and 30 minutes post-infusion."

For Iron Sucrose (Venofer)

No test dose required 1, 3, 6

• Maximum single dose: 200 mg 1, 6
• Administration options:
  • Slow IV bolus: 200 mg undiluted over 2-5 minutes 3, 6
  • IV infusion: 200 mg in 100 mL normal saline over 15-60 minutes 1, 3, 6
• Repeat every 2-3 weeks until total required dose achieved 3
• Written order: "Iron sucrose 200 mg in 100 mL normal saline, infuse over 30 minutes. Repeat weekly × 5 doses (or as needed for total 1000 mg). Monitor vital signs before, during, and 30 minutes post-infusion."

For Ferumoxytol (Feraheme)

No test dose required 1

• Dose: 510 mg × 2 (second dose 3-8 days after first) 1
• Must be given as infusion, NOT rapid push (revised from original labeling due to reactions) 1
• Written order: "Ferumoxytol 510 mg in 250 mL normal saline, infuse over 15 minutes. Repeat in 3-8 days. Notify radiology if MRI planned within 8 weeks. Monitor vital signs before, during, and 30 minutes post-infusion."

Common Pitfalls and Safety Considerations

Test Dose Misconceptions

• LMWID black box warning is not evidence-based for current low molecular weight formulation; older high molecular weight dextran (Dexferrum, discontinued 2009) had 28% adverse event rate 1
• Test dose still required per FDA labeling for LMWID despite equivalent safety to other formulations 1
• Iron sucrose and FCM do NOT require test doses 1, 3
• Consider test dose at physician discretion for iron sucrose if patient has multiple drug allergies or prior iron dextran sensitivity 3

Infusion Reaction Management

• Minor reactions (flushing, paresthesias): Slow infusion rate 7
• Hypotension: Treat with 500 mL normal saline bolus 7
• All formulations show equivalent safety when properly administered 1, 2

Dosing Errors to Avoid

• Do not use Ganzoni formula—it underestimates iron requirements and is prone to error 1
• Simple weight-based dosing is superior: Use body weight and hemoglobin level to determine total dose 1
• Avoid iron overload: Use transferrin saturation >50% and ferritin >800 μg/L as upper limits 1

Clinical Activity Considerations

• Avoid oral iron in clinically active IBD—luminal iron may exacerbate disease activity and alter microbiota 1
• Do not give IV iron during active infection 3

Monitoring Parameters

Baseline:

• Hemoglobin, ferritin, transferrin saturation 1, 8

Follow-up (4-8 weeks post-infusion):

• Hemoglobin (expect 1-2 g/dL increase) 8
• Ferritin and transferrin saturation 8
• Symptom improvement typically within 1-2 weeks 8

Long-term (3 months):

• Ferritin to assess for recurrent deficiency 8