Magnesium Sulphate

Magnesium sulphate is a magnesium salt having sulphate as the counterion. It is a naturally occurring mineral used to control low blood levels of magnesium. Also It has a role as an anticonvulsant, a cardiovascular drug, a calcium channel blocker, an anaesthetic, a tocolytic agent, an anti-arrhythmia drug, an analgesic and a fertilizer.

Magnesium Sulphate is a mineral supplement used to prevent and treat low amounts of magnesium in the blood.  
Used for immediate control of life-threatening convulsions in the treatment of severe toxemias (pre-eclampsia and eclampsia) of pregnancy and in the treatment of acute nephritis in children.
Also indicated for replacement therapy in magnesium deficiency, especially in acute hypomagnesemia accompanied by signs of tetany similar to those of hypocalcemia.
Also used in uterine tetany as a myometriat relaxant.

Common side effects may include diarrhea or upset stomach. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.