Magnesium Sulphate Injection BP Minijet 50% solution for injection.

Magnesium Sulphate Heptahydrate 500mg per ml, equivalent to 2mmol magnesium ions per ml.

The product is available as a vial containing Magnesium Sulphate Heptahydrate 2g in 4ml

For excipients, see section 6.1.

Solution for injection.

A clear, colourless solution practically free from visible particles.

Treatment of magnesium deficiency where the oral route of administration may be inappropriate.

Magnesium sulphate injection may be administered by intramuscular or intravenous routes. For intravenous administration, a concentration of 20% or less should be used; the rate of injection not exceeding 1.5ml/minute of a 10% solution or its equivalent.

Magnesium Sulphate Injection Minijet 50% may be diluted as needed in either 5% dextrose solution or in 0.9% saline solution.

Dosage should be reduced in renal impairment. Plasma magnesium concentrations should be monitored throughout therapy.

Adults

The dosage should be individualised according to patient's needs and responses.

To treat refractory ventricular fibrillation in the presence of hypomagnesaemia, treat with 8mmol (4ml) intravenously.

Mild magnesium deficiency

1g intramuscularly every 6 hours for 4 doses.

Severe magnesium deficiency

Up to 250mg/kg intramuscularly given over 4 hours or 5g/litre of infusion solution intravenously over 3 hours.

Children

It is recommended that the solution be diluted to 20% w/v prior to intramuscular injection.

Elderly

No special recommendations except in renal impairment, see above.

Hypersensitivity to magnesium and it salts. Magnesium sulphate is contraindicated in patients with renal failure.

Magnesium sulphate must be used with caution in patients suspected of or known to have renal impairment. Magnesium Sulphate should not be used in hepatic coma if there is a risk of renal failure.

Administer with caution to patients receiving digitalis glycosides. Magnesium sulphate should not be administered concomitantly with high doses of barbiturates, opioids or hypnotics due to the risk of respiratory depression.

The action of non-depolarising muscle relaxants such as tubocurarine is potentiated and prolonged by parenteral magnesium salts.

Profound hypotension has been reported with concomitant use of nifedipine.

Safety in human pregnancy and during breastfeeding has not been established, therefore, as with all drugs it is not advisable to administer magnesium sulphate during pregnancy or breastfeeding unless considered essential, and it must be administered under medical supervision.

No studies on the effects on the ability to drive and use machines have been performed.

There is a risk of respiratory depression if magnesium sulphate is administered concomitantly with high doses of barbiturates, opioids or hypnotics (see 'Interactions').

Symptoms: Hypermagnesaemia characterised by flushing, thirst, hypotension, drowsiness, confusion, loss of tendon reflexes due to neuromuscular blockade, muscle weakness, respiratory depression, cardiac arrhythmias, coma and cardiac arrest.

Treatment: Maintain respiration with 10% calcium gluconate administered intravenously in a dose of 10-20ml. If renal function is normal adequate fluids should be given to assist removal of magnesium from the body. Dialysis may be necessary in patients with renal impairment or severe hypermagnesaemia.

Pharmacotherapeutic group: Mineral Supplements, ATC code: A12CC 02.

Magnesium is the second most abundant cation in intracellular fluid and is an essential body electrolyte. Magnesium is a factor in a number of enzyme systems, and is involved in neurochemical transmission and muscular excitability.

Parenterally administered magnesium sulphate exerts a depressant effect on the central nervous system and acts peripherally to produce vasodilation.

Following intravenous administration, the onset of action is immediate and the duration approximately 30 minutes. Following intramuscular administration the onset of action occurs after approximately one hour and the duration of action is 3-4 hours.

Magnesium sulphate is excreted by the kidneys with small amounts being excreted in breast milk and saliva.

Preclinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, toxicity to reproduction.

Sulphuric acid

Sodium hydroxide

Water for injections

Magnesium sulphate is incompatible with alkali hydroxides (forming insoluble magnesium hydroxide), alkali carbonates (forming insoluble magnesium carbonate) and salicylates. Streptomycin sulphate and tetramycin sulphate activity is inhibited by magnesium ions.

2 years

Discard any unused solution immediately after first use.

From a microbiological point of view, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and would normally not be longer than 24 hours at 2 to 8°C, unless dilution has taken place in controlled and validated aseptic conditions.

This medicinal product does not require any special storage conditions.

The solution is contained in a type I glass vial with an elastomeric closure and a plastic vial cap. The product is available as 4ml.

An IMS Minijet^®injector is supplied in the carton.

The container is specially designed for use with the IMS Minijet injector.

See 4.2 Posology for information regarding the dilution of this product.

International Medications Systems (UK) Limited

208 Bath Road

Slough

Berkshire

SL1 3 WE

United Kingdom

PL 03265/0077

26^th November 2004