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Iron Infusion

Maladywise

Establish a possible cause of the iron deficiency

Confirm that IV infusion is appropriate

  • Intravenous iron is indicated for the treatment of iron deficiency when oral iron preparations are ineffective or cannot be used.

  • The diagnosis must be based on laboratory tests.

Clinical Indications

  1. Demonstrated intolerance, non-compliance, or lack of efficacy with oral iron despite therapeutic doses (100 to 200 mg of elemental iron a day).

  2. Intestinal malabsorption e.g. inflammatory bowel disease, coeliac disease.

  3. Ongoing iron (blood) losses, not corrected through dietary or oral iron e.g., heavy or irregular menses.

  4. Absolute or functional iron deficiency (ferritin < 100 microgramsl/L) in chronic kidney disease (CKD) or chronic heart failure.

  5. Need for rapid repletion of iron stores in patients:

    • who require surgery within a short time (e.g., < 2 months) with predicted blood loss.

    • with symptomatic anaemia to avoid decompensation and reduce need for transfusion.

    • who are pregnant (not in first trimester) or postpartum.

Check Contraindications

  • The first trimester of pregnancy – has not been studied in pregnancy < 16 weeks

  • Patient aged < 14 years – has not been studied in this age group, therefore not recommended

  • Anaemia not caused by iron deficiency (e.g., haemolysis, disturbances of erythropoiesis)

  • Iron overload (e.g., haemochromatosis, haemosiderosis)

  • Known sensitivity to IV or IM iron (ferric carboxymaltose, iron polymaltose, iron sucrose, or any of its excipients)

Check for Precautions

  • The second or third trimester of pregnancy, unless benefit outweighs risk to fetus. There is limited data on pregnancy > 16 weeks. Fetal bradycardia has been observed which is usually transient and related to maternal hypersensitivity.

  • Uncontrolled hyperparathyroidism, or low vitamin D or phosphate levels.

    • Parenterally administered iron preparations can cause hypophosphataemia which in most cases is transient and without clinical symptoms.

    • Check phosphate levels before infusion if:

      • the patient has had ≥ 2 iron infusions in the preceding 6 months.

      • the patient is at risk of hypophosphataemia (BMI < 18, poor nutrition, chronic diarrhoea).

  • Ferric derisomaltose (Monofer) has a lower incidence of hypophosphataemia than ferric carboxymaltose (Ferinject), and may be preferable if hypophosphataemia is considered a risk.

  • Liver dysfunction – ferric carboxymaltose may lead to a transient rise in liver enzymes and no clinical studies have been performed on patients with hepatic impairment.

  • Asthma, eczema, atopic allergies – increased risk of hypersensitivity reaction.

  • Current infection – erythropoiesis may be suppressed.

  • Chronic inflammatory disease (e.g., rheumatoid arthritis, systemic lupus erythematosus (SLE)) – may be at increased risk of a delayed reaction.

Discuss the Risks of Iron Infusion

Discuss the risks of iron infusion and give the patient an information sheet.

  • Hypersensitivity Effects

    • Nausea, vomiting

    • Dizziness, lightheadedness, loss of consciousness

    • Flushing, a sensation of warmth, tingling, itch, or mild rash

    • Chest pain, racing pulse, changes in blood pressure.

    • Shortness of breath, wheezing

    • Headache, fever, mild back pain, mild chills, and sweats – can occur 1 to 2 days after infusion

  • Anaphylaxis

    Rare, but emergency equipment will be available, and monitoring for 30 minutes after the infusion is recommended.

  • Skin staining

    If extravasation occurs, the iron can cause permanent staining.

Incidence of Side Effects

  • Common (Less than 10%) = Headache, dizziness, flushing, nausea, site reactions, hypophosphataemia

  • Uncommon (Less than 1%) = Skin staining, numbness, tingling, taste change, fast heart rate, shortness of breath, fever

  • Rare (Less than 0.1%) = Malaise, vertigo, syncope, anxiety, angioedema

  • Very rare = Anaphylaxis at 1 in 250,000

Determine the cumulative dose required

Determine the cumulative iron dose required (with the patient's pre-pregnancy weight if pregnant) using the simplified method (for patients with a body weight of ≥ 35 kg), or the Ganzoni method. Give the patient the prescription and ask them to bring with them for the infusion appointment.

Simplified method (for patients with a body weight of ≥ 35 kg)

Haemoglobin (Hb) (g/L) Body weight 35 to < 70 kg. Body weight ≥ 70 kg

< 100. 1500 mg 2000 mg

≥ 100 1000 mg 1500 mg

For patients with a Hb value ≥ 140 g/L, an initial dose of 500 mg iron should be given, and iron parameters should be checked before repeat dosing.

If the cumulative iron dose needed is > 20 mg/kg patient body weight, divide this amount into 2 doses, at least 1 week apart.

The maximum dose per week should not exceed 20 mg/kg or 1000 mg of Ferinject, or 1500 mg of Monofer.

Checklist

On the day of the infusion complete an iron infusion checklist.

Document

References