Prevention of gastrointestinal iron absorption by chelation from an orally administered premixed deferoxamine/charcoal slurry

Study objective: To investigate the effect of an orally administered premixed slurry of deferoxamine mesylate (DFO) and activated charcoal (AC) on the gastrointestinal (GI) absorption of ferrous sulfate under physiologic conditions. Methods: This was a prospective, crossover, controlled human volunteer study. Participants were healthy adult subjects aged 25 to 38 years. Volunteers ingested either 5 mg/kg ferrous sulfate alone, 5 mg/kg ferrous sulfate added to 25 g of 20% (weight/volume) AC, or 5 mg/kg ferrous sulfate added to a premixed slurry consisting of 8 g of DFO and 25 g of 20% (weight/volume) AC. The same group of volunteers was used in each limb of the study. Serum iron concentrations were measured at baseline and at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after ingestion for all subjects. Urinary iron was determined over the first 12 hours after ingestion for each limb. The maximum iron concentration (Cmax), the time to maximum iron concentration (Tmax), and the area under the curve (AUG) were compared for all three limbs. Results: The AUC (P=.042) and Cmax (P=.017) were significantly lower in all subjects in the DFO/AC limb compared with the two control limbs. There was no significant difference in the Tmax iron concentration (P=.77). In the ferrous sulfate control limb, female volunteers had a significantly higher mean Cmax (P=.008) and AUC (P=.014) than males. Iron was undetectable in all baseline and 12-hour urine collections. Conclusion: In this model, a premixed 1:3(weight/weight) DFO/AC slurry reduced the GI absorption of ferrous sulfate in adult volunteers under physiologic conditions.