Magnesium Sulphate 4% infusion
Indications
Magnesium Sulphate 4% infusion is used for:
Convulsions of eclampsia, pre-eclampsia
Adult Dose
Eclampsia
Severe pre-eclampsia or eclampsia
The total initial dose is 10 to 14 g of magnesium sulfate.
To initiate therapy, 4 g of Magnesium Sulfate in 5% Dextrose Injection, may be administered intravenously.
The rate of I.V. infusion should generally not exceed 150 mg/minute, or 7.5 mL of a 2% concentration (or its equivalent) per minute, except in severe eclampsia with seizures.
Simultaneously, 4 to 5 g (32.5 to 40.6 mEq) of magnesium sulfate may be administered intramuscularly into each buttock using undiluted 50% Magnesium Sulfate Injection. After the initial I.V. dose, some clinicians administer 1-2 g/hour by constant I.V. infusion.
Subsequent intramuscular doses of 4 to 5 g of magnesium sulfate may be injected into alternate buttocks every four hours, depending on the continuing presence of the patellar reflex, adequate respiratory function, and absence of signs of magnesium toxicity. Therapy should continue until paroxysms cease.
Child Dose
Renal Dose
Administration
Contra Indications
Heart block, severe renal impairment, myocardial damage.
Precautions
Renal impairment, myasthaenia gravis, digitalised patients; pregnancy. Monitor serum-magnesium concentrations.
Pregnancy-Lactation
Interactions
Enhances neuromuscular blockers, digitalis glycosides.
Side Effects
Side effects of Magnesium Sulphate 4% infusion :
Hypermagnesaemia characterised by nausea, vomiting, flushing, thirst, hypotension, drowsiness, confusion, slurred speech, double vision, bradycardia, muscle weakness. Hypocalcaemia; paralytic ileus.
Mode of Action
Magnesium sulfate decreases levels of acetylcholine in motor nerve terminals. It also acts on the myocardium by decreasing the rate of SA node impulse formation and prolonging the conduction time.