GuidelinesOther guideline
Infusion: Magnesium Sulphate
MAGNESIUM SULPHATE INFUSION
| Trade names: | Presentation and strength: |
| Magnesium sulphate. | 1g/2ml ampoules (500mg/ml). |
| Cautions: see SAMF. Indicated in all eclamptics and severe pre-eclamptics; patients with acute severe asthma. Contra-indicated in myasthenia gravis and heart block. Magnesium toxicity – stop infusion when:
| |
| Loading dose: Obstetric Indication | |
| Adult: 4g loading dose IV over 5 to 10 minutes. | Paediatric: N/A. |
| Commonly for 70kg adult: 4g (8ml) in 200ml saline over 5 to 10 minutes by infusion pump or gravity feed. | Neonatal: N/A. |
| Loading dose: Acute Severe Asthma | |
| Adult: 1-2g loading dose IV over 10 to 20 minutes. (may be repeated x1 only after 12 hrs) | Paediatric: 40 mg/kg Loading dose IV over 20 minutes |
| Constant infusion: | |
| Adult dosage range: 1 to 2g hourly by constant infusion. Start at 1g/hour – for 24 hrs | Paediatric dosage range: N/A. |
| Neonatal dosage range: N/A. | |
| Regime for 70kg adult: | Regime for paediatrics: |
| Mixture: 1g/50ml saline = 20mg/ml. | Mixture: N/A. |
| Rate: 50 to 100ml/hr. | Rate: N/A. |
| Alternative adult regime: | Alternative paediatric regime: |
| Mixture: 4g/200ml = 20mg/ml. | Mixture: N/A. |
| Rate: 50 to 100ml/hr. | Rate: N/A. |
| Additional notes: Eclampsia and pre-eclampsia: The above is known as the Zuspan regimen and is used by GSH. The Pritchard regimen describes the same loading dose, followed by 10g IM (5g into each buttock). Then 5g IM every 4 hours (alternating buttocks). This is continued for 24 hours (limited by some to 12 hours). Suppression of labour: Use 6g loading dose and 2g/hr for suppression of labour where salbutamol contra-indicated or ineffective. | |