Effect of orally administered magnesium hydroxide in experimental iron intoxication

We have previously shown that ferrous and ferric ions readily for complexes with magnesium hydroxide [Mg(OH)2] thus reducing the absorption of iron salts from the gastrointestinal tract. The present study answers the following question: what is the optimal dose, time of administration, optimal limit of effectiveness, and potential hazard of this form of therapy. Adult mongrel dogs were administered ferrous sulfate [FeSO4] tablets at a dosage of 650 mg/lb of body weight. Either 30 or 60 minutes later, the dogs were given Mg(OH)2 at either 5 or l0 times the dose of elemental iron. Serum iron concentrations in all animals given Mg(OH)2 were significantly lower (p less than 0.05) than those of control animals. No significant differences were observed regardless of dose or time of administration of Mg(OH)2. Although serum Mg++ concentrations were significantly elevated (p less than 0.05) om all treated animals 4 and 6 hr post iron, no clinical manifestations of hypermagnesemia were observed. These studies demonstrate the effectiveness of Mg(OH)2 in the management of experimental iron intoxication and warrant a controlled clinical trial in humans.