Nalepsin

Indications

Magnesium Sulphate is a mineral salt. As an injection or infusion it is used to prevent and control fits (seizures) in severe pre-eclampsia and eclampsia, which are dangerous high blood pressure conditions of pregnancy, and to treat or prevent low magnesium levels, for example in people on intravenous feeding. It is also used in hospital for some heart rhythm problems and severe asthma attacks. Taken by mouth as Epsom salt, it acts as a laxative, and it is also found in some intravenous nutrition solutions.

How It Works

Magnesium calms over-excited nerve and muscle cells and relaxes blood vessels and the airways. This helps stop seizures in eclampsia and settles some irregular heart rhythms. In the bowel, magnesium sulphate draws water into the gut, softening stools and speeding up bowel movements.

Dosage and Administration

Injections and infusions are given into a vein or muscle by a doctor or nurse in hospital, with close checks of breathing, knee reflexes, urine output and sometimes blood magnesium levels. The dose depends on the condition and is as prescribed. For occasional constipation, oral Epsom salt is used only as directed on the label, dissolved in water, and not for more than a few days without medical advice.

Interactions

Magnesium can strengthen the effect of muscle relaxants used in anaesthesia and of Nifedipine and other calcium channel blockers (risk of low blood pressure and muscle weakness). Calcium salts reverse its effects. Taken by mouth, magnesium reduces absorption of Tetracyclines, Quinolone antibiotics, Iron and Bisphosphonates; take them at least 2 hours apart.

Contraindications

• Heart block or serious heart muscle damage (injection)
• Myasthenia gravis
• Severe kidney failure
• Oral laxative use: bowel blockage, severe tummy pain of unknown cause, or dehydration

Side Effects

During an infusion, flushing, a feeling of warmth, sweating, nausea, headache, drowsiness and low blood pressure are common. Pain at the injection site may occur. Oral use can cause diarrhoea and tummy cramps.

Get urgent medical help, or tell the nurse at once, if there is slow or shallow breathing, extreme drowsiness, muscle weakness or loss of reflexes, chest pain, a very slow heartbeat, or very little urine.

Pregnancy and Lactation

It is a standard, life-saving treatment in pre-eclampsia and eclampsia and is given in pregnancy under close monitoring. Long courses (more than 5 to 7 days) can affect the baby's bones and are avoided. The baby may need watching for weakness after birth. It can be used while breastfeeding.

Precautions and Warnings

Used with care in kidney problems, as magnesium can build up. Calcium Gluconate injection should be available during infusion as an antidote. Oral laxatives should not be used regularly or in children without medical advice.

Overdose

Too much magnesium causes loss of reflexes, weakness, low blood pressure, slow breathing and, at very high levels, heart stopping. The infusion is stopped and Calcium Gluconate is given; breathing support may be needed.

Therapeutic Class

Electrolyte replacement; anticonvulsant in eclampsia; osmotic laxative

Storage

Injections: store as directed on the pack, below 30°C, do not freeze. Oral powder: store below 30°C in a dry place. Keep out of the reach of children.