T45.4 + (X44.99/X64.99/Y14.99)
DESCRIPTION
Iron is a commonly prescribed drug, especially in pregnancy, and in overdose causes initial gastrointestinal toxicity.
Patients may have a stage of “apparent recovery” 6–36 hours post-ingestion. This should not be confused with true recovery as patients may subsequently deteriorate.
Significant exposure may be associated with:
- severe vomiting and diarrhoea
- gastrointestinal haemorrhage
- metabolic acidosis,
- hypotension, shock
- CNS depression ,
- renal failure, and
- hepatitis.
| Ferrous salt | Amount | Elemental iron |
|---|---|---|
| Ferrous sulphate | 170 mg | ±65 mg |
| Ferrous gluconate | 300 mg | 35 mg |
| Ferrous fumarate | 200 mg | ±65 mg |
GENERAL MEASURES
Gastrointestinal decontamination by whole bowel irrigation is recommended:
- if >60 mg/kg elemental iron has been ingested
- if modified-release preparations ingested
- undissolved tablets still visible on abdominal X-ray
Activated charcoal does not bind iron and is not indicated in isolated iron overdose.
Serum iron concentration should be measured 4–6 hours after ingestion and repeated every 6 hours until peak. The use of desferrioxamine interferes with the interpretation of further serum iron levels.
Give intravenous fluids for hypotension.
MEDICINE TREATMENT
Chelation therapy
Patients with serum iron levels < 54 micromol/L and absence of symptoms > 6 hours after overdose do not require chelation therapy.
Desferoxamine (deferoxamine) may be used for the following indications. If in doubt, consult the Poisons Information Helpline):
- Severe symptoms (altered mental status, hemodynamic instability, metabolic acidosis).
- Serum iron concentration >90 micromol/L.
- Peak serum iron concentration >60 micromol/L, AND persistent gastrointestinal symptoms.
- Desferoxamine (deferoxamine), IV infusion, 15 mg/kg/hour to a total of 80 mg/kg, i.e. given over about 6 hours. Beware of hypotension.
- Note: Prolonged use >24 hours of high doses is associated with acute lung injury and should be avoided. However, in severe poisonings, additional doses may be required.LoEIII [31]
- Desferoxamine can be used in pregnant women.LoEIII [32]
REFERRAL
Haemodialysis may be needed to remove desferoxamine-iron complexes in patients with renal insufficiency.