IV Fe

Q: Intravenous(IV) Iron should be given with? (select one)

A) ideal body weight

B) actual body weight

Answer: B

There are 3 forms of IV Iron available in the USA. 

• Iron dextran 
• Iron sucrose 
• Sodium ferric gluconate

Iron dextran definitely requires a "test dose" in the presence of a physician with epinephrine at the bedside. About 1 out of 200 patients develop life-threatening anaphylaxis. In the remaining 2 forms, a test dose is advisable. Watch time after the 'test dose' is about one hour. IM or SQ administration of Iron is not standard of practice.

Also, the dose should be calculated irrespective of the form of iron used. Various formulae have been described (see references), but the most widely used is

Total amount of iron in mg = { 0.3 x abw (lbs) x 100 (14.8 - present Hgb)] / 14.8

• abw = actual body weight 
• 14.8 is constant as ideal Hb

Iron can also be given in acute blood loss situations. The formula is:

Total iron dose (in mg) = Blood loss (ml) x present Hematocrit.

The total Fe can be given as a single dose in .5 L NS over 6 hours or in divided doses over a few days.

#hematology

References: 

1. Girelli D, Ugolini S, Busti F, Marchi G, Castagna A. Modern iron replacement therapy: clinical and pathophysiological insights. Int J Hematol. 2018 Jan;107(1):16-30. doi: 10.1007/s12185-017-2373-3. Epub 2017 Dec 1. PMID: 29196967.

2. Schaefer B, Meindl E, Wagner S, Tilg H, Zoller H. Intravenous iron supplementation therapy. Mol Aspects Med. 2020 Oct;75:100862. doi: 10.1016/j.mam.2020.100862. Epub 2020 May 19. PMID: 32444112.