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Drug Details

Magnesium Sulphate

• Drug Class Description
  Mineral supplements (minerals).
• Generic Name
  Generic
• Presentation
  Sterile solution for parenteral use.
• Description
  Magnesium Sulphate BP 50% w/v
• Indications
  Treatment of magnesium deficiency where the oral route of administration may be inappropriate, which may be due to malabsorption syndromes, chronic alcoholism, malnutrition, severe diarrhoea or patients on total parenteral nutrition.
• Adult Dosage
  

  Magnesium sulphate injection may be administered by intramuscular or intravenous routes. For intravenous administration, a concentration of 20% or less should be used; the rate of injection not exceeding 1.5ml/minute of a 10% solution or its equivalent.

  Adults

  The dosage should be individualised according to patient's needs and responses.

  Mild magnesium deficiency

  1g intramuscularly every 6 hours for 4 doses.

  Severe magnesium deficiency

  Up to 250mg/kg intramuscularly given over 4 hours or 5g/litre of infusion solution intravenously over 3 hours.

• Elderly Dosage
  

  It is recommended that the solution be diluted to 20% w/v prior to intramuscular injection.

• Contra Indications
  

  Magnesium sulphate is contraindicated in patients with heart block, myocardial damage or impaired renal function.

• Special Precautions
  

  Magnesium sulphate must be used with caution in patients suspected of or known to have renal impairment

• Interactions
  

  Administer with caution to patients receiving digitalis glycosides. Effects of neuromuscular blocking agents may be enhanced. Magnesium sulphate should not be administered concomitantly with high doses of barbiturates, opioids or hypnotics due to the risk of respiratory depression.

  Concomitant use of nifedipine may very rarely lead to a calcium ion imbalance and could result in abnormal muscle function.

• Adverse Drug Reactions
  

  Hypermagnesaemia characterised by flushing, thirst, hypotension, drowsiness, nausea, vomiting, confusion, loss of tendon reflexes due to neuromuscular blockade, muscle weakness, respiratory depression, cardiac arrhythmias, coma and cardiac arrest.

  There is a risk of respiratory depression if magnesium sulphate is administered concomitantly with high doses of barbiturates, opioids or hypnotics