To the Editor.
—Clinically significant hypermagnesemia occurs infrequently in patients with normal renal function.1 A patient is presented who developed hypermagnesemia-induced hypotension and respiratory depression, which was precipitated by the administration of magnesium citrate to a patient with a small-bowel obstruction who had normal renal function.
Report of a Case.
—A 64-year-old woman was admitted with abdominal pain. She had a history of vitamin D deficiency that was well controlled on 1,25(OH)2 [calcitriol] vitamin D and calcium carbonate (CaCO3). She discontinued these medicines 2 years prior to admission. On admission (t= -25 h), she was hypocalcemic, hypomagnesemic, hypokalemic, and had an elevated alkaline phosphatase level. Her serum creatinine level was normal. The patient was treated with calcium, potassium, parenteral magnesium sulfate (MgSO4) (Mg++ 8.1 mmol by continuous infusion from t= -9.7 h through t = -0.3 h) and oral magnesium citrate (Mg++ 125 mmol) at t= -23.7
Zwerling H. Hypermagnesemia-Induced Hypotension and Hypoventilation. JAMA. 1991;266(17):2374-2375. doi:10.1001/jama.1991.03470170062022