Iron Salts

Once daily FeSO4, or one every other day, is enough. Please stop prescribing 3x/day oral iron as this only causes more side effects

About: Always check BNF or equivalent for prescribing advice

• Iron deficiency anaemia may be the only sign of gastrointestinal malignancy.
• Iron overdose is potentially fatal in children and tablets should be kept out of reach

Physiology

• Normal adults need 25 mg of iron to support haemoglobin production in mature erythrocytes.
• This amount is much greater than the 1 to 2 mg absorbed daily through the intestine, and iron needed for erythropoiesis must be acquired from supplies already existing in the body which is usually old RBC's.
• Most iron is recycled internally and new input is to balance the iron loss through bleeding and shedding epithelial cells etc.
• Biological uses of Iron - Enzymes - Cytochromes, Peroxidases, Ribonucleotide reductases, Catalase and Carrier of oxygen in haemoglobin and myoglobin

Mode of action

• Ferric Iron (Fe ³⁺) must be converted to Ferrous Iron (Fe²⁺) for absorption in the gastrointestinal tract.
• Conversion to Ferrous is helped by the low gastric pH, ascorbic acid and protein sulphydryl groups.

Indications

• Normal Nutritional requirement, Pregnancy (Folate may be given as well)
• Treat Iron deficiency anaemia

Contraindications

• Can worsen inflammatory bowel disease
• Avoid in those with strictures

Dose

• Dose depends on iron stores and Hb. : Ferrous sulphate 200 mg once daily or alternate days
• MOre commonly given parenterally (IV/IM). However an cause allergy, hypotension, metallic taste, bradycardia, abdominal pain.

Side effects

• GI upset - nausea, vomiting, constipation and diarrhoea and dark stools

Interactions

• Binds to and reduces the absorption of tetracyclines, quinolones, penicillamine and L-Dopa
• Magnesium antacids can bind and reduce iron intake, Vitamin C increases Iron uptake