What is the recommended rate for intravenous (IV) iron administration?

Recommended Rate for Intravenous (IV) Iron Administration

IV iron should be administered as an undiluted slow bolus injection at 100 mg/min for ferric carboxymaltose (FCM), or over 15 minutes for a 1000 mg dose. 1

Administration Rates by Formulation

Different IV iron formulations have specific recommended administration rates:

Ferric Carboxymaltose (FCM)

• Standard rate: 100 mg/min as undiluted slow bolus injection 1
• Alternative: 1000 mg dose over 15 minutes 1
• Maximum dose: 1000 mg iron (20 mL FCM)/week 1

Iron Dextran (Low Molecular Weight)

• Standard administration: 1000 mg in 250 mL normal saline infused over 1 hour 1
• Test dose required: 25 mg test dose or slow initial infusion for 5 minutes to monitor for reactions 1

Ferric Gluconate

• Standard dose: 125 mg diluted in 100 mL of 0.9% sodium chloride infused over 1 hour 2
• Alternative: Undiluted as slow IV injection at rate of up to 12.5 mg/min 2
• Pediatric dosing: 0.12 mL/kg (1.5 mg/kg elemental iron) diluted in 25 mL 0.9% sodium chloride over 1 hour 2

Iron Sucrose

• Maximum individual dose: 200 mg as slow IV infusion 1

Ferumoxytol

• Standard dose: 510 mg followed by second 510 mg dose 1
• Alternative: 1020 mg over 15 minutes has been studied and found safe 3

Monitoring and Safety Considerations

1. Observation period: Patients should be observed for adverse effects for at least 30 minutes following each IV iron injection 1

2. Infusion reactions:

   • For minor reactions: Stop infusion and restart 15 minutes later at a slower rate 1
   • Avoid diphenhydramine as its side effects can be mistaken for worsening reactions 1

3. Dilution considerations:

   • If administered as an IV infusion, FCM should not be over-diluted as this affects drug stability 1
   • Do not mix IV iron with other medications or add to parenteral nutrition solutions 2

4. Re-evaluation timing:

   • Iron status should be re-evaluated 3 months after IV administration 1
   • Early re-evaluation of iron status is important for determining if additional treatment is needed 1

Practical Considerations

• Formulations capable of administering a replacement dose of 1000 mg in a single 15-60 minute visit are preferable for ambulatory patients 1
• For patients with chronic heart failure and iron deficiency, FCM is recommended with specific dosing based on body weight and hemoglobin levels 1
• The average iron deficit in patients with iron deficiency anemia is approximately 1500 mg, suggesting that a 1000 mg dose may be insufficient for complete iron repletion 4

Common Pitfalls to Avoid

1. Overestimation of transferrin saturation: Shortly after IV administration of iron preparations, spuriously high transferrin saturation levels may occur due to measurement of circulating drug iron 1

2. Inadequate dosing: A total cumulative dose of 1000 mg may be insufficient for iron repletion in most patients with iron deficiency anemia; 1500 mg is closer to the actual iron deficit 4

3. Inappropriate reaction management: Using vasopressors and H1 blockers for minor infusion reactions can convert them into hemodynamically significant adverse events 5

4. Excessive dilution: Over-diluting certain formulations like FCM can affect drug stability and efficacy 1

By following these specific administration rates and monitoring protocols, IV iron therapy can be administered safely and effectively to correct iron deficiency.