Description

Magnesium Sulfate 250 mg/ml, 10 amp 5 ml Solution

Composition

Each ampoule contains 250 mg of magnesium sulfate per ml, resulting in 1250 mg per 5 ml ampoule. Other excipients include sterile water for injections. The solution is clear, colorless, and free from visible particulates.

Description

Magnesium sulfate is an inorganic salt used intravenously for a variety of therapeutic indications, particularly related to electrolyte balance and neuromuscular function. It acts as a central nervous system depressant, smooth muscle relaxant, and anticonvulsant.

Therapeutic Indications

• Prevention and control of seizures in pre-eclampsia and eclampsia
• Treatment of severe hypomagnesemia (magnesium deficiency)
• Adjunct therapy in pediatric acute nephritis to prevent convulsions
• Adjunct in certain cardiac arrhythmias, especially torsades de pointes

Pharmacological Action

Magnesium ions play a critical role in neurochemical transmission and muscular excitability. Magnesium sulfate decreases acetylcholine release at neuromuscular junctions, stabilizes excitable membranes, and inhibits calcium influx into smooth muscle, leading to vasodilation and anticonvulsant effects.

Dosage and Administration

• Pre-eclampsia/Eclampsia: 4–6 g IV over 15–20 minutes as loading dose, followed by maintenance infusion of 1–2 g/hour.
• Hypomagnesemia: 1–2 g IV/IM every 6 hours for 24 hours or as guided by serum magnesium levels.
• Route: Intravenous or intramuscular under medical supervision only.

Dosage should always be individualized based on clinical condition and laboratory parameters.

Contraindications

• Severe renal impairment or renal failure
• Myocardial damage
• Heart block
• Hypermagnesemia
• Hypersensitivity to magnesium sulfate or excipients
• Within 2 hours prior to delivery in pre-eclampsia (due to risk of neonatal depression)

Warnings and Precautions

• Monitor serum magnesium, calcium, and renal function during prolonged therapy
• Assess for early signs of magnesium toxicity (loss of deep tendon reflexes, respiratory depression)
• Use cautiously in patients with cardiac disease or conduction disturbances
• Calcium gluconate should be available as an antidote to reverse magnesium toxicity

Adverse Reactions

• Common: Flushing, sweating, hypotension, nausea, depressed reflexes
• Serious: Respiratory paralysis, cardiac arrhythmias, CNS depression, circulatory collapse
• Injection site pain and phlebitis (with IV use)

Drug Interactions

• Enhances neuromuscular blockade of agents such as succinylcholine and tubocurarine
• Risk of severe hypotension with calcium channel blockers (e.g., nifedipine)
• May potentiate cardiac toxicity of digitalis glycosides
• Use cautiously with CNS depressants and opioids

Use in Pregnancy and Lactation

Magnesium sulfate is commonly used in pregnancy for pre-eclampsia and eclampsia but should not be administered within 2 hours of delivery. Neonatal respiratory depression may occur. Small amounts may be excreted into breast milk. Use only under medical supervision.

Overdose

Overdose symptoms include facial flushing, loss of reflexes, muscle weakness, bradycardia, respiratory depression, and cardiac arrest. Immediate treatment involves discontinuation and administration of IV calcium gluconate, ventilatory support, and hemodialysis in severe cases.

Storage

• Store below 25°C (77°F) in a cool, dry place
• Do not freeze
• Keep ampoules in original packaging and protect from light
• Do not use if solution is cloudy or contains particles

Scientific References

• Magnesium Sulfate – StatPearls – NCBI Bookshelf
• Magnesium sulfate in obstetrics – PubMed