Iron overdosage is an acute emergency requiring urgent medical attention. An acute intake of 75mg/kg of elemental iron is considered extremely dangerous in young children.
Symptoms:
Initial symptoms of iron overdosage include nausea, vomiting, diarrhoea, abdominal pain, haematemesis, rectal bleeding, lethargy and circulatory collapse. Hyperglycemia and metabolic acidosis may occur. However, if overdosage is suspected, treatment should be implemented immediately. In severe cases, after a latent phase, relapse may occur after 24-48 hours manifested by hypotension, coma, hypothermia, hepatocellular necrosis, renal failure, pulmonary oedema, diffuse vascular congestion, coagulopathy and/or convulsions. In many cases, full recovery may be complicated by long-term effects such as hepatic necrosis, toxic encephalitis, CNS damage and pyloric stenosis.
Treatment:
The following steps are recommended to minimise or prevent further absorption of the medication.
Children:
1. Administer an emetic such as syrup of ipecac.
2. Emesis should be followed by gastric lavage with desferrioxamine solution (2g/l). This should then be followed by the installation of desferroxamine 5g in 50 – 100ml water, to be retained in the stomach. Inducing diarrhoea in children may be dangerous and should not be undertaken in young children. Keep the patient under constant surveillance to detect possible aspiration of vomitus – maintain suction apparatus and standby emergency oxygen in case of need.
3. Severe poisoning:
In the presence of shock and/or coma with high serum iron levels (serum iron >90umol/l) immediate supportive measure plus IV infusion of desferrioxamine should be instituted. Desferrioxamine 1 5mg/kg body weight should be administered every hour by slow IV infusion to a maximum 80mg/kg/24 hours.
Warning:
Hypotension may occur if the infusion rate is too rapid.
4. Less severe poisoning: i.m desferroxamine 1g 4-6-hourly is recommended.
5. Serum iron levels should be monitored throughout.
Adults:
Treatment of iron overdose in pregnancy should be as for the non-pregnant patient and if clinically indicated, treatment with desferrioxamine should not be withheld.
1. Administer an emetic.
2. Gastric lavage may be necessary to remove drug already released into the stomach.
This should be undertaken using a desferrioxamine solution (2g/l).
Desferrioxamine 5g in 50-100ml water should be introduced into the stomach following gastric emptying. Keep the patients under constant surveillance to detect possible aspiration of vomitus; maintain suction apparatus and standby emergency oxygen in case of need.
3. A drink of mannitol or sorbitol should be given to induce small bowel emptying.
4. In the presence of shock and/or coma with high serum iron levels (>142umol/l) immediate supportive measures plus IV infusion of desferrioxamine should be instituted.
The recommended dose of desferrioxamine is 5mg/kg/h by a slow IV infusion up to a maximum of 80mg/kg/24 hours.
Warning:
Hypotension may occur if the infusion rate is too rapid.
5. Less severe poisoning:
i.m. deferrioxamine 50mg/kg up to a maximum dose of 4g should be given.
6. Serum iron levels should be monitored throughout.