Epsom salt, also known as magnesium sulfate, is a drug that is available over the counter and by prescription. For OTC use, it is taken orally and used as a soak. Prescription uses include shots and intravenous use. This product is used to treat a variety of conditions, including seizures, rapid heartbeat, skin wounds and constipation.
Epsom salts relax the blood vessels, which can lower blood pressure. This is a benefit for someone who suffers from hypertension, or high blood pressure. However, for someone whose blood pressure is below 120/80, which is normal according to MedlinePlus, lowering blood pressure too much can lead to hypotension and cause medical complications like dizziness and shock.
One of the common uses of Epsom salt is as a laxative. However, in some people, this can cause severe diarrhea and other gastrointestinal problems, such as vomiting. Severe diarrhea and vomiting can cause dehydration. Diarrhea is noted by loose and watery stools. Symptoms of dehydration include thirst, dry skin, fatigue, irritability, dark colored urine and infrequent urination, according to the National Digestive Diseases Information Clearinghouse.
Toxicity from Epsom salts occurs when a person overdoses on the salts. Drugs.com lists the symptoms of this danger as drowsiness, vomiting, nausea and flushing. It is also possible for this effect of Epsom salts to be so severe that an individual becomes comatose. To minimize this risk, if a dose of Epsom salts is missed and it is almost time for another dose, the missed dose should be left alone and the medication schedule should continue on the regular schedule.
Epsom salts, like any other drug or supplement, may cause an allergic reaction. Signs of an allergic reaction include a rash; itching; and/or swelling of the face, tongue or lips; difficulty breathing; or hives. Anyone who experiences these symptoms should seek emergency medical attention.