Classes
DEA Class; OTC
Common Brand Names;
- Antidotes, Other
Description
Co-factor in enzymatic processes
Slows the rate of S-A node impulse formation in the myocardium and prolongs conduction time
Stabilizes excitable membranes by promoting the movement of sodium, calcium, and potassium in and out of the cell
Indications
Indicated in Digitalis Toxicity, Hydrofluoric acid burns
Indicated for the treatment of documented hypomagnesemia or for torsades de pointes (polymorphic VT associated with long QT interval)
There is insufficient evidence to recommend for or against the routine administration of magnesium during cardiac arrest
Contraindications
Hypersensitivity
Heart block or myocardial damage
Diabetic coma
Myasthenia gravis
Adverse Effects
Flushing
Hypotension
Hypothermia
CNS depression
Motor & respiratory paralysis
Abnormal ECG
Diarrhea
Heart block
Prolonged bleeding time
Warnings
Serum levels poorly correlate to body stores
Solutions containing dextrose should be used with caution in patients with known prediabetes or diabetes mellitus given the risk of elevated blood glucose
Do not use in 5% dextrose Injection with unapproved tocolytics (eg, beta-adrenergic agents such as terbutaline, or with calcium channel blockers such as nifedipine); serious adverse events including pulmonary edema and hypotension have occurred
Pregnancy and Lactation
Continuous administration of magnesium sulfate beyond 5-7 days in pregnant women can lead to hypocalcemia and bone abnormalities in the developing fetus, including skeletal demineralization and osteopenia; in addition, cases of neonatal fracture reported
Use of intravenous magnesium in pregnant women increases human milk magnesium concentrations only slightly and oral absorption of magnesium by infant is poor; the effect of intravenous magnesium on milk production is unknown
Maximum Dosage
Digitalis Toxicity
1-2 g IVP over 5 minutes, then 1 g/hr drip (if Digibind not available)
Monitor levels q2hr; therapeutic goal is 4.5 mEq/L
Other Indications & Uses
Hydrofluoric acid burns
Pediatric
25-50 mg/kg IV/IO over 10-20 minutes (may infuse faster in torsades de pointes); not to exceed 2 g/dose
Kleinman ME, et al. Circ 2010 Nov;122(18):S876-S908
How supplied
Magnesium Antidotw
IV infusion, premixed in D5W
10mg/mL
20mg/mL
IV infusion, premixed in water
40mg/mL
80mg/mL
injection for dilution
500mg/mL