Magnesium citrate Advanced Drug Monograph

Magnesium Citrate Report

Name: Magnesium citrate Name (English): Magnesium citrate DrugBank ID: DB11110 Type: Small Molecule CAS Number: 3344-18-1

Magnesium citrate is a magnesium salt of citric acid with the molecular formula $\text{C}{12}\text{H}{10}\text{Mg}3\text{O}{14}$ and a molecular weight of 451.113 g/mol. It may exist as an anhydrous or hydrated salt.

Pharmacology: Magnesium citrate is an osmotic laxative that works by increasing fluid in the small intestine, which stimulates bowel movements. The high osmolality of the solution draws large amounts of fluid into the colonic lumen. It may also stimulate fluid excretion by cholecystokinin release and activation of muscle peristalsis. Magnesium is also an essential mineral involved in numerous enzymatic reactions and physiological processes.

Indications:

• Bowel preparation before medical procedures like colonoscopy.
• Relief of occasional constipation.
• Magnesium supplementation for the treatment or prevention of hypomagnesemia.

Dosage & Administration: Dosage varies depending on the indication and patient age. For constipation in adults, 195-300 mL of oral solution in a single daily dose or divided doses with a full glass of water, or 2-4 tablets at bedtime. For bowel preparation, a healthcare professional will provide specific instructions. As a nutritional supplement, the recommended daily allowance for magnesium varies by age and sex.

Contraindications:

• Bowel obstruction or perforation
• Ileus
• Severe abdominal pain
• Nausea or vomiting
• Rectal bleeding
• Kidney disease

Adverse Effects: Common side effects include abdominal discomfort, cramping, gas, and nausea. More serious side effects may include persistent diarrhea, severe abdominal pain, slow or irregular heartbeat, mental or mood changes, muscle weakness, and dehydration.

Drug Interactions: Magnesium citrate can interact with several medications, including:

• Certain antibiotics (e.g., ciprofloxacin, levofloxacin) by decreasing their absorption.
• Bisphosphonates (e.g., alendronate) by decreasing their absorption.
• Diuretics (e.g., amiloride, acetazolamide) increasing the risk of dehydration.
• Other medications, including bictegravir, cabotegravir, deferiprone, deflazacort, fleroxacin, gemifloxacin, ifosfamide, moxifloxacin, ofloxacin, aclidinium, alfentanil, alloin, almasilate, aluminium phosphate, aluminum hydroxide, amantadine, amiodarone, amitriptyline, and amlodipine.

Pharmacokinetics: The onset of action for laxative effects can range from 30 minutes to 3 hours. Magnesium citrate is primarily eliminated via feces. Approximately 24-76% of ingested magnesium is absorbed in the gastrointestinal tract.

Precautions:

• Use with caution in patients with kidney disease.
• Prolonged or frequent use may lead to laxative dependence and electrolyte imbalances.
• Ensure adequate fluid intake when using magnesium citrate as a laxative.
• Consult a healthcare professional before use during pregnancy or breastfeeding.

Storage: Liquid formulations should be refrigerated to maintain potency and palatability. Store other forms according to the product label.