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.