What is the best course of treatment for a 41-year-old male patient with resolved upper respiratory complaints and current constipation, currently taking fiber lax (fiber laxative) and considering milk of magnesia (magnesium hydroxide)?

From the Guidelines

I strongly recommend continuing the prescribed treatment for constipation with Milk of Magnesia 30 ml every night for five days, as well as the fiber laxative the patient is already taking, as this approach is supported by the most recent guidelines from the American Gastroenterological Association and the American College of Gastroenterology 1. The patient's upper respiratory symptoms have resolved completely, with no coughing, chest pain, runny nose, or other discomfort reported for the past week, indicating successful resolution of the initial complaint. However, the patient now reports constipation, which is being addressed with a two-pronged approach. Fiber laxatives work by adding bulk to stool and promoting regular bowel movements through increased water retention in the intestines. Milk of Magnesia (magnesium hydroxide) complements this by acting as an osmotic laxative, drawing water into the intestines and stimulating bowel movements while also neutralizing stomach acid. This combination approach should effectively address the constipation while the patient's respiratory condition appears to have resolved without need for further intervention. Key points to consider in the management of constipation include:

• Gradual increase in fiber intake, as recommended by the American Gastroenterological Association 1
• Use of osmotic agents like milk of magnesia or polyethylene glycol, as suggested by both 1 and 1
• Consideration of stimulant laxatives if symptoms persist, as outlined in the guidelines 1
• The importance of patient motivation and a tailored approach to therapy, as highlighted in the 2023 guideline 1.

From the FDA Drug Label

PRINCIPAL DISPLAY PANEL - 30 mL Cup Tray Label NDC 0121-0431-30 Milk of Magnesia USP ANTACID, SALINE LAXATIVE Each 30 mL contains: Magnesium Hydroxide 2400 mg Active ingredient (in each 5 mL) Magnesium hydroxide 400 mg

The patient is to be prescribed milk of magnesia 30 ml every night for five days.

• The usual dosage is not specified in the provided text, only that it can be found in the attached Drug Facts Package.
• The prescription of 30 ml every night for five days will contain 2400 mg of Magnesium Hydroxide per dose, as each 30 mL contains this amount 2.
• This is equivalent to 480 mg of Magnesium Hydroxide per 5 mL, as each 5 mL contains 400 mg of Magnesium Hydroxide 2, and 30 mL is six times 5 mL. The decision to prescribe this dosage should be based on the attached Drug Facts Package and clinical judgment. 2 2

From the Research

Treatment of Constipation

The patient is experiencing constipation and is currently taking fiber lax. To address this issue, milk of magnesia 30 ml every night for five days has been prescribed.

• The use of milk of magnesia as a treatment for constipation is supported by studies, which classify laxatives according to their actions on the gut 3.
• Osmotic laxatives, such as milk of magnesia, are a popular therapeutic option for the treatment of constipation, especially when fiber is not successful or tolerated 4.
• A systematic review of over-the-counter therapies for chronic constipation found good evidence to recommend polyethylene glycol or senna as first-line laxatives, and moderate evidence supporting fiber supplements, fruits, stimulant laxatives, and magnesium-based products 5, 6.
• Another study compared the laxation of psyllium with and without senna in an ambulatory constipated population, and found that both laxatives increased defecation frequency and stool weights, although the added effect of senna was clearly evident 7.

Efficacy and Safety of Treatment

The efficacy and safety of milk of magnesia as a treatment for constipation have been established in various studies.

• A review of available data concerning several bulk and fiber products, lubricating agents, stimulants, and osmotic laxatives found that popular therapeutic options for initial treatment of chronic constipation are dietary fiber and medicinal bulk 4.
• A systematic review of over-the-counter therapies for chronic constipation found that the spectrum of OTC products has increased and the quality of evidence has improved, but methodological issues remain 5.
• The use of milk of magnesia as a treatment for constipation is generally well tolerated, with common adverse effects being abdominal pain, cramping, bloating, diarrhea, and nausea 5, 6.