Paradoxical hypomagnesemia caused by excessive ingestion of magnesium hydroxide.

Excessive ingestion of magnesium may lead to hypermagnesemia even without kidney dysfunction. Several cases of development of hypermagnesemia after overdose of magnesium hydroxide have been reported. Although magnesium hydroxide is widely used as laxative, its overdose may induce diarrhea, which is followed by excessive magnesium loss. I report a case of paradoxical hypomagnesemia developed after excessive ingestion of magnesium hydroxide. A 39-year-old woman was presented to the emergency department complaining of severe watery diarrhea and carpopedal spasm after ingesting a handful of magnesium hydroxide tablets. The laboratory tests detected hypomagnesemia, hypocalcemia, and normokalemia. Calcium gluconate was given to the patient, but her symptom did not improve shortly. The symptom disappeared spontaneously 2 days after the watery diarrhea subsided. This case shows that overdose of magnesium hydroxide, which leads to massive diarrhea, might induce hypomagnesemia unexpectedly. This case also suggests that it should be treated, as well as typical magnesium deficiency.

Severe hypermagnesemia as a result of excessive cathartic ingestion in a child without renal failure.

A 14-year-old girl was referred to our hospital with lethargy and hypotension and was found to have a serum magnesium level of 14.9 mg/dL after having received an magnesium hydroxide (Magnesie Calcinee) for 7 days because of constipation. She was lethargic, her blood pressure was 70/40 mm Hg, and electrocardiogram revealed prolonged corrected QT interval and first-degree atrioventricular block. She has no renal dysfunction. Emergency hemodialysis after her condition ameliorated, her serum magnesium levels returned to normal. The present case suggests that massive oral magnesium ingestion with severe constipation and ileus may result severe hypermagnesemia without renal dysfunction.

Magnesium intoxication in a neonate from oral magnesium hydroxide laxative.

This is a case of magnesium intoxication in a neonate produced by an oral magnesium cathartic. A review of the literature revealed there are very few cases that have been reported of magnesium toxicity due to cathartics. There is no recommended dose for magnesium cathartics in neonates or data on their safety. A review of the management of magnesium intoxication is presented.

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.