MAGNESIUM SULFATE IS USED IN CARDIAC ARREST ONLY IF THE PATIENT IS POSSIBLY HYPOMAGNESEMIC OR IN TORSADES DE POINTES. Other uses include life-threatening arrhythmia as a result of digoxin toxicity.
In cardiac arrest due to hypomagnesemia or torsades de pointes, give 1 to 2 grams IV or IO. The magnesium should be given as 2 to 4 ml. of a 50% solution, diluted in 10 ml of D5W or normal saline.
In torsades with a pulse or in the case of acute MI with suspicion of hypomagnesemia, a loading dose of 1 to 2 grams mixed in 50 to 100 ml. of D5W or normal saline should be given IV over 5 to 60 minutes. This may be followed with a dose of 0.5 to 1 gram per hour IV, titrated to control torsades de pointes.
Routine use in acute myocardial infarction is not recommended.
May cause hypotension if rapidly administered.
Use cautiously in renal failure.