Abstract
The effect of a chelating agent, trisodium calcium diethylenetriaminepentaacetate (DTPA), in seven patients with thalassemia major and secondary hemochromatosis is reported. Urinary excretion of iron, copper, magnesium and calcium was measured prior to and following intramuscular injections of DTPA. As much as a 16-fold increase in excretion of iron (up to 40 mg./24 hours) and a 3½-fold increase in excretion of copper were achieved. Magnesium and calcium in urine remained consistently below the average range for normal individuals although excretion of magnesium increased 15-60 per cent and calcium as much as 550 per cent following administration of this agent.
While serum levels of copper were high and plasma calcium levels low normal or slightly reduced, plasma magnesium levels were found to be slightly to significantly low in all patients studied. The latter were transiently further reduced following injection of DTPA and may have been related to symptoms of magnesium deficiency in one patient.
This agent was effective in removal of iron particularly in the older patients with secondary hemochromatosis. However, attention is drawn to the possible hazardous effect of DTPA on magnesium metabolism in patients with thalassemia major.
