Hypermagnesemia associated with catharsis in a salicylate-intoxicated patient with anorexia nervosa.
While clinicians have raised concerns about giving multiple doses of a cathartic as a part of therapy for acute poisoning, fears of excessive magnesium absorption or fluid or electrolyte imbalances have been largely unrealized. We present the case of a 19-year-old woman with anorexia nervosa and long-term laxative abuse who, despite a normal baseline serum magnesium concentration, developed hypermagnesemia during treatment with multiple doses of activated charcoal-magnesium citrate for acute salicylate intoxication. The peak serum magnesium concentration, after two doses of magnesium citrate, reached 9.8 mg/dL (4.0 mmol/L). It fell to normal levels when sorbitol was substituted as a cathartic and after the patient had been hemodialyzed for symptoms of salicylate toxicity that continued despite conventional therapy. While disordered magnesium metabolism in one patient with a severe underlying medical condition should not interdict the use of repetitive doses of magnesium citrate as a cathartic, patients requiring such therapy should have serum magnesium concentrations measured serially to monitor for signs of magnesium loading.
Gren
J
J
Division of Pharmacology & Toxicology, Children's Hospital, Boston, Massachusetts.
Woolf
A
A
D000328:Adult; D000856:Anorexia Nervosa / Q000150:complications*; D000863:Antacids / Q000009:adverse effects; D001241:Aspirin / Q000506:poisoning*; D002400:Cathartics / Q000009:adverse effects*; D002951:Citrates / Q000009:adverse effects* / Q000627:therapeutic use; D019343:Citric Acid; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood*
D000863:Antacids; D002400:Cathartics; D002951:Citrates; D019343:Citric Acid; D008274:Magnesium; D001241:Aspirin