Pronunciation: mag-NEE-zee-um KLOR-ide
- Injection, solution, concentrate 20% (elemental magnesium 1.97 mEq/mL)
Magnesium is an important activator of many enzyme systems, and deficits are accompanied by a variety of functional disturbances.
Immediately absorbed (IV).
Approximately 1% to 2% of total body magnesium is the extracellular fluid space; 30% bound to albumin.
Magnesium is not metabolized.
Excreted solely by the kidneys at a rate proportional to the serum concentration and glomerular filtration.
Special PopulationsRenal Function Impairment
No data available.Hepatic Function Impairment
No data available.
Indications and Usage
Electrolyte replenisher in magnesium deficiencies.
Renal impairment; marked myocardial disease; comatose patients.
Dosage and AdministrationMagnesium Deficiency
IV 1 to 40 g daily.
- For IV infusion only. Not for intradermal, IM, subcutaneous, or intra-arterial administration.
- To prepare IV infusion, use 4 g in 250 mL of dextrose 5% injection.
- Administer at a rate not exceeding 3 mL/min.
- Serum magnesium levels should serve as a guide to continued dosage.
- Have an IV calcium preparation on hand as an antidote.
- Prior to repeat doses, test for knee-jerk reflexes. If they are absent, no additional magnesium should be given until reflexes return.
- Incompatibilities: streptomycin, tetracycline, tobramycin.
Store at 59° to 86°F.
Drug InteractionsAlcohol, aminoglycosides, amphotericin B, cisplatin, cyclosporine, digitalis, diuretics
Drug-induced renal losses of magnesium can occur. Use with caution and closely monitor magnesium concentrations.Neuromuscular blocking agents (eg, pancuronium)
Potentiation of neuromuscular blockade. Use with caution. Monitor for respiratory depression. Adjust the neuromuscular blocking agent dose as needed. Be prepared to provide life support.Nifedipine
The risk of neuromuscular blockade and hypotension may be increased. Closely monitor the clinical response. Be prepared to provide supportive treatment or to discontinue one or both drugs if needed.
Sharply lowered BP.
Flushing, hypothermia, sweating.
Monitor serum magnesium levels and the patient's clinical status to guide need for continued dosage. Normal serum concentration is 1.5 to 2.5 or 3 mEq/mL. Monitor levels hourly for patients with severe hypomagnesemia until they reach 1.5 mEq/mL, then every 6 to 12 h for the next 24 h. Once stable, obtain the serum concentration daily. Carefully observe respiration and BP during and after administration of IV magnesium. Maintain urine output at 100 mL every 4 h. Clinical indications of a safe dosage regimen include the presence of the patellar reflex (knee-jerk) and absence of respiratory depression (approximately 16 or more breaths per min). When repeated doses of the drug are given parenterally, knee-jerk reflexes should be tested before each dose; if they are absent, no additional magnesium should be given until they return. The strength of the deep tendon reflexes begins to diminish when magnesium levels exceed 4 mEq/L. Reflexes may be absent at magnesium 10 mEq/L, where respiratory paralysis is a potential hazard.
Category C .
Excreted. The American Academy of Pediatrics classifies magnesium sulfate as compatible with breast-feeding.
Dosing information not provided for children. Some of these products may contain benzyl alcohol. Benzyl alcohol has been associated with a fatal gasping syndrome in premature infants.
Contraindicated in patients with renal impairment.
Some products contain aluminum. Aluminum may reach toxic levels with parenteral administration if kidney function is impaired. Premature neonates are particularly at risk.
Administer with caution if either occurs.
Decreased deep tendon reflexes, disappearance of patellar reflex, hypotension, muscle weakness, prolonged PR interval, prolonged QRS complex, prolonged QT interval, respiratory paralysis, sedation, sharp drop in BP.
- Advise patient that medication will be prepared and administered by a health care provider in a hospital setting.
- Advise patient to discontinue use and notify health care provider if dizziness, drowsiness, flushing, muscle weakness, or sweating occurs.
Copyright © 2009 Wolters Kluwer Health.
More Magnesium Chloride resources
- magnesium chloride sustained-release tablets MedFacts Consumer Leaflet (Wolters Kluwer)
- magnesium chloride Concise Consumer Information (Cerner Multum)
- Chloromag Prescribing Information (FDA)