Depletion oftraceelements andacuteocular toxicity induced bydesferrioxamine inpatients with thalassaemia

SUMMARY Highdosesofintravenousdesferrioxamine infused overa short period oftime induce a large faecal and urinary iron excretion but also produce retinal abnormalities that are characterisedbydecreasedamplitude on electroretinography anddefectivedark adaptation. Thisregimenalso results in highfaecaliron, zinc, and copper excretion, andreduced granulocytezincconcentrations andalkaline phosphataseactivity. Theretinal abnormalities may be relatedto thezinc and copper deficiency and/or iron depletion 'per se' whichinterferes negatively with criticaliron dependent enzymes. Subcutaneous infusion of desferrioxamine is themostefficient methodfor reducing the iron burdenin patients with thalassaemia major whoare trans-fusion dependent. 1 The daily infusion of 40-60 mg/kg over12hoursforsix daysaweekis usuallysufficient to obtain iron balance.'v Because somepatients fail to comply with this regimen the addi-tional administration of large doses by intravenousinfusion hasbeenproposed.3 Highdosesofdesferri-oxamine, either by intravenous or subcutaneous