# Parenteral Iron Replacement For Anemia Calculator

Estimates the parenteral dose of iron supplement needed to restore hemoglobin level.

There is more information on the formula used and on normal haemoglobin levels in the text below the form.

The parenteral iron replacement calculator determines the amount of iron supplements that is needed to replenish iron stores and balance haemoglobin levels, depending on the weight and haemoglobin levels of the patients.

There is also an adjustment available, depending on the type of elemental iron product desired to be used.

The formula used to discover the iron deficit in mg is:

Iron deficit (mg) = Patient weight in kg x (14 – Hb in g/dL) x 2.145

The volume of product required to replenish iron stores is:

Volume of product (mL) = Iron deficit in mg / C in mg/mL

Where C is the concentration of the iron product:

■ 50 mg/mL for Iron dextran;

■ 20 mg/mL for Iron sucrose;

■ 5 mg/mL for Ferric gluconate.

Weight:*
Hemoglobin:*
Elemental iron product:
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Steps on how to print your input & results:

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.

## Variables and formula

This parenteral iron calculator uses the patient weight and haemoglobin level to compute the iron deficit.

Hb levels are extracted from the complete blood count test.

There is flexibility in terms of the measurement unit for the variables used: weight can be input in either kg or lbs whilst haemoglobin can be input in g/dL, g/L or mmol/L.

There is also a third variable which requests for the type of elemental iron product intended for replenishment of iron stores. The choice is between Iron dextran 50 mg/mL, Iron sucrose 20 mg/mL and Ferric gluconate 12.5 mg/mL.

The formula used for iron deficit is:

Iron deficit (in mg) = Weight (in kg) x (14 – Hemoglobin in g/dL) x 2.145

The volume of product in mL can be calculated by diving the iron deficit to the mg/mL value of the product used, which is:

■ 50 mg/mL for Iron dextran;

■ 20 mg/mL for Iron sucrose;

■ 5 mg/mL for Ferric gluconate.

It is important to note that the above calculations merely provide estimates and that individual dosage should be established by a medical professional based on the current package insert for the elemental iron product used.

The following table introduces the normal haemoglobin ranges for three categories of patients and in three measurement units:

 Patient Hb in g/dL Hb in g/L Hb in mmol/L Male 13.8 – 18 138 – 180 8.56 – 11.17 Female 12.1 – 15.1 121 – 151 7.51 – 9.37 Child 11 – 16 110 – 160 6.83 – 9.93

The iron deficiency calculator uses a similar calculation method (the Ganzoni formula) for replenishments needs but also accounts for existent iron stores.

## Parenteral and oral iron supplement

When a patient is discovered with iron deficiency during control tests, iron supplementation therapy is prescribed to balance depleted body stores or correct any possible anemia.

Oral iron therapy is the first preferred method whilst IV therapy usually comes in when there are contraindications or the body doesn’t respond to oral iron.

In some cases of pregnancy iron deficiency, renal impairment or after acute haemorrhage, IV iron is recommended because the initial haemoglobin rise is more rapid. However, on the long term (3 months), both oral and parenteral iron have similar effects on haemoglobin.

Therapy with iron-dextran or iron-carboxymaltose is total dose whilst with iron sucrose is split dose.

## References

1. Ganzoni AM. Intravenous iron-dextran: therapeutic and experimental possibilities. Schweiz Med Wochenschr. 1970; 100(7):301-3.

2. Auerbach M, Witt D, Toler W, Fierstein M, Lerner RG, Ballard H. Clinical use of the total dose intravenous infusion of iron dextran. J Lab Clin Med. 1988; 111(5):566-70.

3. Koch TA, Myers J, Goodnough LT. Intravenous Iron Therapy in Patients with Iron Deficiency Anemia: Dosing Considerations. Anemia. 2015; 2015: 763576.

Specialty: Deficiency

System: Digestive

Objective: Determination

Type: Calculator

No. Of Variables: 3

Abbreviation: 1970

Article By: Denise Nedea

Published On: May 18, 2017

Last Checked: May 18, 2017

Next Review: May 18, 2023