2, oral absorption, can form a hypertonic state in the intestine, reduce the absorption of water, increase intestinal contents, cause intestinal peristalsis, cause diarrhea, used for jejunum contents before surgery or colonoscopy. At present, sodium sulfate is commonly used instead of magnesium sulfate, which is weaker and safer. Use with caution during menstruation, pregnancy and the elderly.

3, local external application can eliminate local edema.

4. Long-term use of magnesium sulfate will cause habitual constipation.

5. Intravenous injection of magnesium sulfate and intramuscular injection are mainly used as anticonvulsants, which can cause vasodilation and lower blood pressure. Because of the central inhibitory effect of magnesium sulfate and the relaxation and hypotensive effect of skeletal muscle, it is mainly used to relieve convulsions such as eclampsia and tetanus, and also to treat hypertensive crisis. Adverse reactions include: high blood magnesium can cause respiratory depression, sudden drop of blood pressure, cardiac arrest and death. The disappearance of tendon reflex is a precursor of respiratory depression, so tendon reflex should be checked frequently during continuous medication. In case of poisoning, artificial respiration should be carried out immediately, and calcium chloride or calcium gluconate should be slowly injected intravenously for emergency rescue.