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.