Effect of oral calcium disodium EDTA on iron absorption in a human model of iron overdose.
OBJECTIVE
Anecdotal case reports and animal models have suggested that the administration of CaNa2EDTA (EDTA) may be effective in reducing the absorption of iron after an oral iron overdose. We designed this study to determine the effect of orally administrated EDTA with or without activated charcoal (AC) on iron absorption after a mild iron ingestion in healthy human volunteers.


METHODS
A randomized, crossover study was conducted in eight healthy human volunteers. All subjects ingested 5 mg/kg of elemental iron in the form of ferrous sulfate. One hour post ingestion, subjects were randomized to receive 35 mg/kg EDTA, EDTA plus 50 grams of AC, or water. Serial iron levels were obtained at baseline and every hour for the first 6 hours, then at 8, 12, and 24 hours. A 2-week washout was used between study arms. The Kruskal-Wallis test was used for the following comparisons between treatment groups: baseline serum iron levels, area under time-concentration curves (AUCs) from baseline to 12 hours and baseline to 24 hours, and peak iron levels.


RESULTS
Baseline serum iron levels did not differ among the three treatment groups (p = 0.844). AUCs were not different among groups (p = 0.746 for 12 hr, p = 0.925 for 24 hr). AUC medians (with 95% binomial confidence bounds) for control, EDTA, EDTA + AC groups, respectively, for 12 hr were: 2813 (2298, 3561), 2570 (1669, 3476), and 2654 (2125, 3600); and for 24 hr were: 4083 (3488,5314), 4139 (2666, 5547), and 4274 (3336, 5577). Peak serum iron levels did not differ among treatment groups (p = 0.481). Peak iron level medians in microg/dL (with 95% binomial confidence bounds) were for control: 329 (253, 382), for EDTA: 271 (184, 375), and for EDTA + AC: 285 (229, 352).


CONCLUSIONS
Orally administered EDTA did not significantly reduce iron absorption when administered 1 hour post iron ingestion during the 12 or 24-hour period following the ingestion of 5 mg/kg of elemental iron in healthy human volunteers.
Department of Emergency Medicine, Naval Medical Center San Diego, California 92103-8925, USA. mmatteucci@cox.net
Michael J
MJ
Matteucci
Michael
M
Habibe
Kristie
K
Robson
Accursia A
AA
Baldassano
Robert H
RH
Riffenburgh
David A
DA
Tanen
D000284:Administration, Oral; D000328:Adult; D000931:Antidotes / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology*; D018592:Cross-Over Studies; D062787:Drug Overdose / Q000188:drug therapy; D004492:Edetic Acid / Q000494:pharmacology*; D005260:Female; D005296:Ferrous Compounds / Q000008:administration & dosage; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007501:Iron / Q000097:blood / Q000506:poisoning*; D008297:Male; D011041:Poisoning / Q000188:drug therapy
D000931:Antidotes; D002614:Chelating Agents; D005296:Ferrous Compounds; C020748:ferrous sulfate; D004492:Edetic Acid; D007501:Iron