Haematology/Iron (haematinic)

Iron

also: ferrous sulfate · ferrous fumarate · ferric carboxymaltose · iron

Overview

Treatment of iron-deficiency anaemia — oral first-line; IV when oral not tolerated/absorbed. The response check and the black-stools point are exam staples.

Mechanism

Provides elemental iron for haemoglobin synthesis. Oral ferrous salts absorbed in the duodenum (better with vitamin C, worse with food/tea/calcium/PPIs). A rise of ~20 g/L Hb over ~4 weeks confirms response.

Indications

Iron-deficiency anaemia
Prophylaxis (pregnancy, post-bariatric, etc.)

The agents

Ferrous sulfate / fumarate / gluconateoral

Continue ~3 months after Hb normalises to replenish stores; alternate-day dosing improves absorption/tolerance.

Ferric carboxymaltose (IV)IV

Malabsorption / intolerance / rapid replacement (e.g. antenatal); anaphylaxis risk.

Adverse effects

GI upset, constipation, black stoolscommon

Black stools are expected (distinguish from melaena clinically).

Overdose: especially dangerous in childrenserious

Antidote = desferrioxamine.

IV iron: anaphylaxis, staining at injection siteserious

Cautions & contraindications

Investigate the CAUSE before/with treatingall

IDA in an adult = exclude GI malignancy (colorectal).

Interactions

Absorption ↓ by PPIs, calcium, tetracyclines/quinolones (chelation), tea

Monitoring & kinetics

FBC at ~2–4 weeks (expect Hb rise ~20 g/L/month); ferritin

Oral (alternate-day) or IV. Take with vitamin C, away from food/antacids.

Source: NICE CKS — Anaemia - iron deficiency · BNF — Iron