About magnesium sulfate heptahydrate
Electrolyte replacement; anticonvulsant
Used for
- Treats or prevents low blood magnesium.
- Prevents and treats seizures in severe pre-eclampsia and eclampsia.
- Used in selected cases of severe acute asthma.
Usual adult dose
For low magnesium, commonly 1–5 g intravenously, adjusted to blood levels. For eclampsia, typically 4–6 g loading dose, then 1–2 g/hour.
Usual dose in children
For low magnesium, commonly 25–50 mg/kg intravenously, with specialist monitoring. Not a routine childhood treatment for eclampsia.
Common side effects
- Flushing and sweating
- Nausea
- Low blood pressure
- Muscle weakness
Important warnings
- Excess can cause dangerously slow breathing, weak reflexes, heart rhythm problems, or cardiac arrest.
- Requires monitoring of blood levels, breathing, reflexes, kidney function, and heart rhythm.
- Use cautiously with kidney impairment; magnesium may accumulate.
- Intravenous administration must be controlled and monitored by trained healthcare professionals.
Pregnancy
Used under medical supervision for eclampsia and other specific indications; prolonged use may harm fetal bones.
Breastfeeding
Generally compatible with breastfeeding when used briefly; intravenous treatment may temporarily delay milk production.
Interactions
- Calcium-channel blockers may increase low blood pressure or muscle weakness.
- Neuromuscular-blocking medicines may cause prolonged muscle weakness.
- Other medicines that depress breathing may increase respiratory risk.
- Calcium can counteract magnesium toxicity and may be needed in emergencies.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.