Iron deficiency due to chronic blood loss. Pregnancy, foetus takes up to 600mg of iron from the mother even if she is iron deficient in various abnormalities of the gastro-intestinal tract where the proportion of dietary iron absorbed may be reduced in premature babies. During the treatment of severe pemicious anaemia
The oral dose of elemental iron for deficiency should be 100 to 200mg daily. It is customary to give this as dried ferrous sulphate 200mg (equivalent to 65 mg of elemental iron) three times daily; a dose of ferrous sulphate 200mg once or twice daily may be effective for prophylaxis or for mild iron deficiency
History of peptic ulcer, severe renal failure, iron and tetracycline bind together leading to impairment of absorption
Gastro-intestinal irritation may occur with iron salts. Nausea and epigastric pain or dose related but the relationship between dose and altered bowel habit (constipation or diarrhea) is less clear – oral iron, particularly modified release preparations, may exacerbate diarrhea in patients with inflammatory bowel disease.
Iron poisoning is commonest in children and is usually accidental hypotensions, coma and hepatocellular necrosis occur later
Treatment of overdose
If side effects occur the dose may be reduced alternatively another iron salt may be used, but on improvement in tolerance may simply be a result of lower content of elemental iron