Mag-SR Side Effects
Generic Name: magnesium chloride
Note: This document contains side effect information about magnesium chloride. Some of the dosage forms listed on this page may not apply to the brand name Mag-SR.
For the Consumer
Applies to magnesium chloride: oral tablet delayed release
Other dosage forms:
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Very upset stomach or throwing up.
- Very loose stools (diarrhea).
What are some other side effects of this drug?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Loose stools (diarrhea).
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to magnesium chloride: compounding powder, injectable solution, oral tablet extended release
Other side effects have resulted from toxicity (hypermagnesemia). Mild hypermagnesemia is generally well-tolerated. Moderate or severe hypermagnesemia primarily affects the nervous and cardiovascular systems. The effects of hypermagnesemia may be worsened by the presence of hypocalcemia, especially in patients with uremia.[Ref]
Gastrointestinal side effects have included diarrhea. Magnesium toxicity has been associated with nausea (magnesium levels of 4 to 5 mEq/L) and rare cases of paralytic ileus (magnesium levels greater than 5 mEq/L).[Ref]
Nervous system side effects have resulted from the suppression of neuromuscular transmission in the CNS and at the neuromuscular junction by magnesium (antagonized by calcium). The degree of severity of these side effects has been dependent on the serum magnesium level. Clinically, if serum magnesium (Mg) levels increase to 4 to 7 mEq/L, there may be a decrease in tendon reflexes, muscle weakness and/or mental confusion/sedation. At levels of 7 to 10 mEq/L the respiratory rate slows and the blood pressure falls. At levels of 10 to 15 mEq/L there is usually profound mental depression, areflexia, coma and respiratory paralysis. Magnesium also has a curare-like effect at the neuromuscular junction at serum levels above 10 mEq/L. Death is not uncommon when serum magnesium levels rise to 15 mEq/L.[Ref]
The cardiovascular consequences of hypermagnesemia are due to peripheral vasodilation. Hypotension may be observed when serum magnesium levels rise to 7 to 10 mEq/L, becoming severe when serum magnesium levels rise above 10 mEq/L. Magnesium can also depress myocardial conductivity at levels greater than 10 mEq/L. This can result in bradyarrhythmias. While some patients are inexplicably able to tolerate extraordinary magnesium levels, there is a significant risk of asystole when levels rise to 25 mEq/L. The risk of cardiotoxicity from hypermagnesemia is increased in the presence of hypocalcemia, hyperkalemia, acidosis, digitalis therapy, and renal insufficiency.[Ref]
Cardiovascular side effects have included hypotension, depressed myocardial conductivity and asystole.[Ref]
Acute hypermagnesemia may cause hypocalcemia due to suppression of the release of parathyroid hormone (PTH) and competition for renal tubular reabsorption between calcium (Ca) and magnesium. The latter can lead to decreased Ca reabsorption and hypercalciuria, which aggravates the hypocalcemia produced by decreased release of PTH.[Ref]
Metabolic side effects have included hypocalcemia.[Ref]
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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.
More about Mag-SR (magnesium chloride)
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- Drug class: minerals and electrolytes
Other brands: Chloromag