Recommended Dosing for Polyethylene Glycol (PEG) in Treating Constipation
The recommended dosing for Polyethylene Glycol (PEG) in treating constipation is 17 g once daily mixed in 4-8 ounces of liquid, with demonstrated efficacy for up to 6-12 months of continuous use. 1, 2
Standard Dosing Recommendations
- For adults and children 17 years of age and older, the FDA-approved dose is 17 g of PEG 3350 once daily mixed in 4-8 ounces of any beverage (cold, hot, or room temperature) 2
- The American Gastroenterological Association strongly recommends PEG compared with management without PEG for chronic idiopathic constipation (CIC) based on moderate certainty of evidence 3
- PEG should be fully dissolved in liquid before drinking and should not be combined with starch-based thickeners used for difficult swallowing 2
- For over-the-counter use, PEG 3350 should not be used for more than 7 days without consulting a doctor 2
Dosing Based on Formulation
- PEG 3350 without electrolytes: 17 g once daily mixed in 8 ounces of liquid 3, 1
- PEG with electrolytes: 17.5 g twice daily dissolved in 250 mL of water (based on clinical trials) 3
- For severe constipation or fecal impaction, higher doses may be required - up to 68 g has been shown to be effective and safe for rapid relief within 24 hours 4, 5
Duration of Treatment
- Response to PEG has been shown to be durable over 6 months in controlled clinical trials 3, 6
- Long-term safety studies have demonstrated PEG to be safe and effective for treating constipation for up to 12 months, with no evidence of tachyphylaxis 7
- For chronic idiopathic constipation, extended use beyond the FDA-approved 7-day limit may be appropriate under medical supervision 1, 7
Efficacy and Response
- PEG significantly increases complete spontaneous bowel movements (CSBMs) per week compared to placebo (MD 2.90, CI 2.12–3.68) 3
- PEG also increases spontaneous bowel movements (SBMs) per week (MD 2.30, CI 1.55–3.06) 3
- Response rates are high, with studies showing 52% of PEG users achieving treatment success compared to only 11% with placebo 6
- Efficacy is maintained in elderly patients, with 84-94% reporting successful treatment 7
Side Effects and Safety Considerations
- Common side effects include abdominal distension, loose stool, flatulence, and nausea 3, 1
- Diarrhea is more common with PEG than placebo (158 more per 1,000 patients) but is generally mild to moderate in severity 3, 1
- Long-term studies show no clinically significant changes in hematology or blood chemistry, particularly electrolytes, even with extended use 7
- PEG is contraindicated in patients with known or suspected gastrointestinal obstruction 5
Implementation Tips
- A trial of fiber supplement can be considered for mild constipation before PEG use or in combination with PEG 3
- For children 16 years of age or under, consult a doctor before using PEG 2
- For optimal results, ensure the PEG powder is completely dissolved before drinking 2
- PEG is widely available without prescription and is relatively inexpensive, making it appropriate for early use in constipation management 3