Use of Intravenous Magnesium Sulphate
| Element | Comment |
|---|---|
| Loading dose | Magnesium sulphate 4g by slow IV bolus over 5–10 min |
| Maintenance infusion | 1g/h magnesium sulphate for 24h, or 24h after last seizure Omit maintenance infusion if oligo-anuric |
| Therapeutic level | Aim for Mg level of 2–4 mmol/L |
| Caution | Caution with concurrent use of calcium antagonists as the use of both can lead to profound hypotension |
| Observation during infusion | Check reflexes (upper and lower limb) – before treatment, every 30 min for first two hours and then every hour |
| Management of suspected overdose | Overdose causes muscle weakness, and so if reflexes are absent the infusion should be stopped and a Mg level checked |
| Antidote | Calcium gluconate 1g IV |