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Question: Metabolic
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A 20-month old child is brought in by ambulance for lethargy and altered mental status. You find out his grandmother has been administering frequent doses of milk of magnesia to treat constipation. You suspect hypermagnesemia.
Kelly October 11, 2023 - 6:07 pm
B) Activated charcoal
Hypermagnesemia is rare in children but can occur iatrogenically. Hypothyroidism, adrenal insufficiency, and renal failure are rare causes. Symptoms include nausea and vomiting, flushing, weakness, progressing to lethargy, decreased deep tendon reflexes, and at high levels coma and flaccid paralysis. Magnesium acts as a calcium channel blocker and cardiac effects including hypotension, bradycardia, and prolonged PR, QRS, and QTc intervals can occur. Magnesium may also inhibit PTH secretion, leading to hypocalcemia. Calcium therapy is used both when hypocalcemic and for cardiac stabilization at high Mg++ levels. All of the above therapies may be used in the treatment of this patient except for activated charcoal: 1) the patient has altered mental status and cannot protect his airway, and 2) the liquid MOM is likely absorbed already and cannot be removed by charcoal use.