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Magnesium Sulfate

    Brands

    DEA Class; Rx

    Common Brand Names; MgSO4

    • Antidysrhythmics, V; 
    • Electrolytes

    Depresses CNS, blocks peripheral neuromuscular transmission, produces anticonvulsant effects; decreases amount of acetylcholine released at end-plate by motor nerve impulse

    Slows rate of SA node impulse formation in myocardium and prolongs conduction time

    Promotes movement of calcium, potassium, and sodium in and out of cells and stabilizes excitable membranes

    Promotes osmotic retention of fluid in colon, causing distention and increased peristaltic activity, which subsequently results in bowel evacuation

    Indicated for the treatment of Hypomagnesemia, Torsades de Pointes

    Indicated to prevent seizures associated with pre-eclampsia, and for control of seizures with eclampsia

    Used as a tocolytic to stop preterm labor

    Hypersensitivity

    Myocardial damage, diabetic coma, heart block

    Hypermagnesemia

    Hypercalcemia

    Administration during 2 hours preceding delivery for mothers with toxemia of pregnancy

    • Circulatory collapse
    • Respiratory paralysis
    • Hypothermia
    • Pulmonary edema
    • Depressed reflexes
    • Hypotension
    • Flushing
    • Drowsiness
    • Depressed cardiac function
    • Diaphoresis
    • Hypocalcemia
    • Hypophosphatemia
    • Hyperkalemia
    • Visual changes

    Fetal skeletal demineralization, hypocalcemia, and hypermagnesemia abnormalities reported with continuous long-term use (ie, longer than 5-7 days) for off-label treatment of preterm labor in pregnant women; the effect on the developing fetus may result in neonates with skeletal abnormalities

    In patients with renal impairment, ensure that renal excretory capacity is not exceeded

    Use with caution in digitalized patients

    Use with extreme caution in patients with myasthenia gravis or other neuromuscular disease

    Hypomagnesemia is usually associated with hypokalemia (potassium levels must be normalized)

    Monitor renal function, blood pressure, respiratory rate, and deep tendon reflex when magnesium sulfate is administered parenterally

    Pregnancy category: D

    Fetal skeletal demineralization, hypocalcemia, and hypermagnesemia reported with continuous long-term use (ie, longer than 5-7 days) for off-label treatment of preterm labor in pregnant women; the effect on the developing fetus may result in neonates with skeletal abnormalities

    Continuous administration of magnesium sulfate injection to treat preterm labor is not approved and that the safety and efficacy of use for this indication are not established

    Lactation: Safe

    Adults

    Mild: 1 g IM q6hr for 4 doses

    Severe

    • Asymptomatic: 4-8 g at ≤1 g/hr
    • Symptomatic: 4-8 g at ≤4 g over 4-5 min

    4-5 g (diluted in 250 mL NS/D5W) IV in combination with either (a) up to 10 g (20 mL of undiluted 50% solution) divided and administered IM into each buttock or (b) after initial IV dose, 1-2 g/hr IV; may administer q4hr as necessary

     

    Magnesium Sulfate

    injectable solution

    • 40mg/mL
    • 80mg/mL
    • 50%

    infusion solution

    • 1g/100mL
    • 2g/100mL