Magnesium Sulphate

SOURCE: UK SPC (eMC) for Magnesium Sulfate 10% w/v solution for infusion, §4.2 (https://www.medicines.org.uk/emc/product/10502/smpc). RECURRENT CONVULSIONS: if convulsions recur, a further 2–4 g (8–16 mmol) of magnesium ions (20–40 ml of a 10% solution, depending on the woman's weight — 2 g (8 mmol) if less than 70 kg) is given IV over 5 minutes. SECOND SPC INDICATION — treatment of magnesium deficiency in hypomagnesaemia: up to 40 g or 160 mmol of magnesium ions (400 ml of a 10% solution) by slow intravenous infusion (in glucose 5%) over up to 5 days may be required to replace the deficit (allowing for urinary losses). TITRATION/MONITORING: dosage should be tailored to the individual patient's needs and responses; plasma magnesium concentrations should be measured to determine the rate and duration of infusion and should be monitored throughout therapy. Serum calcium levels should be routinely monitored. ELDERLY: no special recommendation — use with caution due to the risk of renal impairment in this age group. PAEDIATRIC POPULATION: the SPC states 'No special recommendation' and gives no paediatric regimen. PREGNANCY: fetal heart rate should be monitored and use within 2 hours of delivery should be avoided; continuous administration for more than 5 to 7 days can cause fetal skeletal adverse effects. GAP — this SPC covers only hypomagnesaemia and eclampsia. It does NOT contain the acute severe asthma, torsades de pointes or refractory VF regimens shown on this page; those regimens must be sourced separately (national asthma / resuscitation guidance) and verified by the clinician. For instructions on dilution before administration see SPC §6.6.