← Search & browse all drugs
ALIMENTARY TRACT AND METABOLISM › MINERAL SUPPLEMENTS › OTHER MINERAL SUPPLEMENTS › Magnesium
magnesium chloride
A12CC01
Forms & Strengths
- Oral tablets: 535 mg (providing 64 mg elemental magnesium)
- Oral capsules: 400 mg
- Oral liquid solution: various concentrations (e.g., 50 mg/mL elemental magnesium)
- Intravenous injection: 200 mg/mL in 50 mL vials
Adult Dosing
- Hypomagnesemia: Oral: 540 to 1080 mg elemental magnesium daily in divided doses
- Severe hypomagnesemia / Torsades de pointes (IV): 1 to 2 g diluted in 50 to 100 mL D5W or NS infused over 5 to 60 minutes
- Maintenance IV replacement: 1 to 3 g daily as continuous infusion
Pediatric Dosing
- Hypomagnesemia (Oral): 10 to 20 mg/kg of elemental magnesium per dose 2 to 4 times daily
- Hypomagnesemia / Severe deficiency (IV): 25 to 50 mg/kg per dose (maximum 2 g per dose) infused over 1 to 2 hours, may repeat every 8 to 12 hours as needed
Indications
- Treatment and prevention of magnesium deficiency (hypomagnesemia)
- Management of acute hypomagnesemic seizures
- Adjunctive treatment of cardiac arrhythmias such as Torsades de pointes
- Magnesium supplementation in total parenteral nutrition (TPN)
Mechanism of Action
- Magnesium is an essential intracellular cation acting as a cofactor for numerous enzymatic reactions
- Regulates membrane stability, neuromuscular transmission, and vasomotor tone
- Antagonizes calcium channels, producing smooth muscle relaxation and decreased neuromuscular excitability
- Plays a vital role in neurochemical transmission and cardiac electrophysiology
Contraindications
- Myocardial damage or severe myocardial disease (e.g., severe heart block)
- Diabetic ketoacidosis during acute phase
- Anuria or severe renal impairment (creatinine clearance < 25 mL/min)
- Known hypersensitivity to magnesium salts
Adverse Reactions
- Gastrointestinal: Diarrhea, abdominal cramping, nausea (primarily with oral administration)
- Cardiovascular: Hypotension, flushing, bradycardia, cardiac arrest (with rapid IV administration)
- Neurological: Drowsiness, confusion, depressed deep tendon reflexes, muscle weakness
- Metabolic: Hypermagnesemia, hypocalcemia, hyperkalemia
Drug Interactions
- Neuromuscular blockers: Enhanced and prolonged neuromuscular blockade
- Aminoglycoside antibiotics: Increased risk of neuromuscular blockade and respiratory depression
- Fluoroquinolones and tetracyclines: Oral magnesium decreases absorption of these antibiotics via chelation; separate administration by 2 hours
- Digitalis glycosides: Hypermagnesemia may alter cardiac conduction and precipitate arrhythmias; use with extreme caution
Curated Content: Needs Vetting Before Put to Clinical Use