Magnesium sulfate (commonly called Epsom salts or bitter salts in hydrated form) is a chemical compound with the formula MgSO₄·7H₂O.

Origin

Epsom salt was originally prepared by boiling down mineral waters at Epsom, England and afterwards prepared from sea water. In more recent times, these salts are obtained from certain minerals such as siliceous hydrate of magnesia . It is used as a therapeutic bath.

Medical use

It is taken orally as a laxative, and to treat heartburn or constipation.

Intravenous use is broadening, as magnesium sulfate reduces striated muscle contractions and blocks peripheral neuromuscular transmission by reducing acetylcholine release at the myoneural junction. Indications for its use are:

• Prevention and treatment of seizures (especially in eclampsia, for which it is the most effective therapy).
• As a bronchodilator after beta-agonist and anticholinergic agents have been tried, e.g. in severe exacerbations of asthma.
• In some cardiac arrhythmias:
  • Atrial fibrillation
  • Torsades de pointes tachycardia