From the Guidelines
Magnesium citrate should be used with caution in geriatric patients with constipation, starting at a lower dose which may be increased if necessary, while avoiding use in patients with renal insufficiency due to the risk of hypermagnesemia. When considering the use of magnesium citrate in elderly patients, it is essential to prioritize their unique needs and potential risks. According to the American Gastroenterological Association-American College of Gastroenterology clinical practice guideline 1, the panel suggests starting at a lower dose, which may be increased if necessary, and avoiding use in patients with renal insufficiency due to the risk of hypermagnesemia.
Some key considerations for the use of magnesium citrate in geriatric patients include:
- Starting with a lower dose and adjusting as needed
- Avoiding use in patients with renal insufficiency
- Ensuring adequate hydration before and after administration
- Considering non-pharmacological approaches such as increased dietary fiber, adequate hydration, and physical activity before recommending magnesium citrate
- Being aware of potential drug interactions, particularly with antibiotics and bisphosphonates
It's also important to note that elderly patients are more susceptible to dehydration and electrolyte imbalances, so close monitoring is necessary. The laxative effect of magnesium citrate occurs through osmotic action, drawing water into the intestinal lumen and stimulating bowel movements, typically within 30 minutes to 6 hours. As recommended by the guidelines, treatment should be short-term only, not exceeding 1-2 days of use, and magnesium citrate is contraindicated in patients with severe renal impairment, intestinal obstruction, or acute abdominal conditions 1.
In terms of specific guidance for geriatric patients, the ESMO clinical practice guidelines for managing constipation in older people with cancer suggest that laxatives must be individualized and targeted to the older person’s medical history, drug interactions, and adverse effects 1. However, the most recent and highest quality study, the American Gastroenterological Association-American College of Gastroenterology clinical practice guideline 1, provides more direct guidance on the use of magnesium citrate in geriatric patients.
Overall, the use of magnesium citrate in geriatric patients with constipation requires careful consideration of their unique needs and potential risks, and should be guided by the most recent and highest quality evidence available 1.
From the FDA Drug Label
Directions shake well before using drink a full glass (8 ounces) of liquid with each dose may be taken as a single daily dose or in divided doses adults and children 12 years of age and over - 6.5 to 10 fl oz maximum 10 fl oz in 24 hours The FDA drug label does not answer the question.
From the Research
Guidelines for Magnesium Citrate Use in Geriatrics
- The use of magnesium citrate in geriatric patients with constipation requires careful consideration of the potential risks and benefits 2.
- A study published in 2005 reported a case of severe hypermagnesemia in an elderly woman who ingested 34g of magnesium citrate, highlighting the importance of monitoring serum magnesium levels in this population 2.
- Another study published in 1987 found that magnesium hydroxide was more effective than bulk-laxative in treating constipation in elderly long-stay patients, with a more frequent bowel habit and more normal stool consistency 3.
Dosage and Administration
- The optimal dosage of magnesium citrate for geriatric patients with constipation is not well established, but a study published in 2009 suggested that a combination of sodium picosulfate and magnesium citrate may be effective and well-tolerated in this population 4.
- A study published in 2011 found that magnesium citrate with a single dose of sodium phosphate was as effective and tolerable as the conventional sodium phosphate regimen for colonoscopy bowel preparation in older patients 5.
Safety and Tolerability
- Magnesium citrate may be associated with a dehydrating effect, and older patients may require additional electrolytes 4.
- The tolerability profile of sodium picosulfate/magnesium citrate in patients aged >70 years is reportedly similar to that in patients aged <70 years 4.
- A study published in 2019 found that oral magnesium sulfate solution in split doses was well-tolerated and effective in elderly patients undergoing colonoscopy, with a low incidence of adverse reactions 6.
Special Considerations
- Geriatric patients with renal dysfunction or other underlying medical conditions may require closer monitoring and adjustment of the dosage of magnesium citrate 2.
- The use of magnesium citrate in combination with other medications, such as sodium phosphate, may increase the risk of adverse reactions and requires careful consideration 4, 5.