Iron Salts
💊 Modern practice: Once daily or alternate-day ferrous sulphate (FeSO₄) is sufficient.
⚠️ Please stop prescribing TDS oral iron — this only increases side effects without added benefit.
❗ Iron overdose is potentially fatal in children → always keep tablets out of reach.
📖 About
- Iron deficiency anaemia may be the first sign of GI malignancy → always investigate underlying cause in adults.
- Iron is essential for haemoglobin, myoglobin, and many enzymes (cytochromes, peroxidases, ribonucleotide reductases, catalase).
- Most body iron is recycled from old red blood cells; dietary absorption (1–2 mg/day) just replaces normal losses (bleeding, skin, GI epithelium).
🧪 Physiology
- Adults need ~25 mg iron daily for RBC production, but only 1–2 mg is absorbed through the intestine.
- Absorption requires ferric (Fe³⁺) iron to be reduced to ferrous (Fe²⁺) form in the stomach.
- Low gastric pH, ascorbic acid (vitamin C) and sulphydryl groups help this conversion.
🎯 Indications
- Iron deficiency anaemia (treat the cause + replace stores).
- Increased requirements (e.g. pregnancy — folate often co-prescribed).
- Prevention in high-risk groups with poor diet or chronic blood loss.
💊 Dose
- Ferrous sulphate: 200 mg once daily (65 mg elemental iron) or on alternate days (better tolerated & improves absorption).
- Continue for 3 months after Hb normalises to replenish iron stores.
- IV iron may be used if oral not tolerated, absorption is poor, or rapid correction is needed (e.g. in CKD, IBD, pre-op) — but can cause allergy, hypotension, metallic taste, bradycardia, abdominal pain.
⛔ Contraindications & Cautions
- Active or severe inflammatory bowel disease (may worsen symptoms).
- Oesophageal/gut strictures (risk of mucosal damage with tablets).
- Use with care in older patients (constipation) and those at risk of non-compliance.
💢 Side Effects
- GI upset — nausea, constipation, diarrhoea, epigastric pain.
- Dark stools (benign but alarming to patients).
- Poor adherence due to side effects is common.
🔄 Interactions
- ⬇️ Reduced absorption with tetracyclines, quinolones, penicillamine, levodopa, bisphosphonates.
- ⬇️ Magnesium/aluminium antacids reduce absorption.
- ⬆️ Vitamin C (ascorbic acid) enhances absorption.
📚 References
