What is the role of Polyethylene Glycol (PEG) in relieving constipation?

From the Guidelines

Polyethylene glycol (PEG) is a highly effective treatment for constipation, and its use is strongly recommended as a first-line therapy for adults with chronic idiopathic constipation (CIC) 1.

Key Points

• For adults, the recommended dose is 17 grams of PEG 3350 (such as MiraLAX) mixed in 8 ounces of water once daily 1.
• PEG can be taken at any time of day, with or without food, for up to 7 days for occasional constipation, and its effects have been shown to be durable over 6 months 1.
• PEG works by drawing water into the intestines, softening stool and making it easier to pass without causing cramping or urgency, and it typically produces a bowel movement within 1-3 days.
• PEG is not absorbed into the bloodstream, making it safe for most people, including pregnant women and the elderly 1.
• It is essential to drink plenty of water throughout the day while using PEG to help the medication work effectively.
• If constipation persists beyond 7 days of treatment, it is crucial to consult a healthcare provider as this may indicate a more serious condition requiring evaluation.

Mechanism of Action and Efficacy

PEG is an osmotic laxative that acts by increasing the amount of water in the stool, making it softer and easier to pass 1. The studies have consistently shown that PEG is associated with a greater efficacy in increasing complete spontaneous bowel movements (CSBMs), spontaneous bowel movements (SBMs), responder rate, improvements in stool form, straining, and global relief compared with placebo 1.

Safety and Side Effects

While PEG is generally safe and well-tolerated, individuals treated with PEG may experience bloating, flatulence, and diarrhea, which are consistent with and expected from laxative therapy, and most of these events were mild or moderate 1.

Clinical Considerations

A trial of fiber supplement can be considered for mild constipation before PEG use or in combination with PEG, and response to PEG has been shown to be durable over 6 months 1. It is also important to note that PEG is widely available without the need for a prescription and is relatively inexpensive, making it a reasonable option for earlier use in the algorithm for the management of CIC.

From the FDA Drug Label

USE • relieves occasional constipation (irregularity) • generally produces a bowel movement in 1 to 3 days The role of Polyethylene Glycol (PEG) in relieving constipation is as an osmotic laxative that helps to increase the amount of water in the stool, making it softer and easier to pass.

• It relieves occasional constipation
• It generally produces a bowel movement in 1 to 3 days 2

From the Research

Role of Polyethylene Glycol (PEG) in Relieving Constipation

• Polyethylene Glycol (PEG) 3350 is an osmotic laxative that has been shown to be safe and effective in relieving constipation in adults 3, 4, 5, 6, 7.
• Studies have demonstrated that PEG 3350 can increase the frequency of bowel movements, improve stool consistency, and reduce symptoms of constipation such as straining and hard or lumpy stools 3, 5, 6, 7.
• The optimal dose of PEG 3350 for relieving constipation has been found to be 17-34 g per day, with the best efficacy seen in the second week of treatment 3.
• PEG 3350 has been compared to other treatments for constipation, such as tegaserod, and has been found to have superior efficacy and fewer side effects 5.
• PEG 3350 is also effective in relieving constipation caused by medications, with a significant improvement in bowel movement frequency and consistency compared to placebo 6.
• In subjects with occasional constipation, PEG 3350 has been shown to provide significant relief from straining and reduction in hardness of stools over a 7-day period 7.

Efficacy of PEG 3350

• Studies have consistently shown that PEG 3350 is effective in relieving constipation, with response rates ranging from 36.7% to 78.3% 3, 5, 6, 7.
• PEG 3350 has been found to be effective in improving stool frequency, consistency, and completeness of evacuation, as well as reducing symptoms of constipation such as straining and hard or lumpy stools 3, 5, 6, 7.
• The efficacy of PEG 3350 has been demonstrated in various patient populations, including adults with chronic constipation, patients taking constipating medications, and subjects with occasional constipation 3, 4, 5, 6, 7.

Safety and Tolerability of PEG 3350

• PEG 3350 has been found to be safe and well-tolerated, with no significant differences in adverse events compared to placebo 3, 4, 5, 6, 7.
• The most common adverse events reported with PEG 3350 are gastrointestinal in nature, such as diarrhea and flatulence, but these are generally mild and transient 3, 4, 5, 6, 7.
• PEG 3350 has been found to have no significant effects on laboratory parameters, such as electrolytes, calcium, glucose, BUN, creatinine, or serum osmolality 3, 6.