Polyethlyene Glycol (PEG)

Indications

  • Bowel Preparation for Colonoscopy (see Colonoscopy, [[Colonoscopy]])
  • Constipation (see Constipation, [[Constipation]])

Pharmacology

  • Osmotic Laxative

Metabolism

  • xxxx

Administration

  • PO (Miralax = Polyethylene Glycol 3350): xxx
  • PO (Golytely): xxx

Dose Adjustment

  • Hepatic:
  • Renal:

Adverse Effects

Cardiovascular Adverse Effects

Exacerbation of Congestive Heart Failure (CHF) (see Congestive Heart Failure, [[Congestive Heart Failure]])

  • Epidemiology
    • PEG May Exacerbate Congestive Heart Failure [MEDLINE]: case report
  • Physiology
    • PEG Gavage May Increase Plasma Volume [MEDLINE]: PEG gavage may either decrease and increase plasma volume, as patients exhibit individual variability (range: 9.8% decrease in plasma volume to 29.8% increase in plasma volume)

Pulmonary Adverse Effects

Other Adverse Effects

  • xxx
  • xxx
  • xxx

References

  • The effect of polyethylene glycol gavage on plasma volume. J Surg Res. 1994 Aug;57(2):284-8 [MEDLINE]
  • Exacerbation of congestive heart failure after administration of polyethylene glycol-electrolyte lavage solution. Ann Pharmacother. 1995 Dec;29(12):1232-35 [MEDLINE]

Bowel Prep

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3678056/

http://www.asge.org/assets/0/71542/71544/4424ba4c2f1e4df9baf1fe6e4e854b5b.pdf


Expert Opin Drug Metab Toxicol. 2011 Jan;7(1):89-101. doi: 10.1517/17425255.2011.542411.
Mechanism of action and toxicities of purgatives used for colonoscopy preparation.

Adamcewicz M1, Bearelly D, Porat G, Friedenberg FK.
Author information

Abstract
IMPORTANCE OF THE FIELD:
In developed countries, colonoscopy volume has increased dramatically over the past 15 years and is the principle method used to screen for colon cancer. Preparations used for colon cleaning have evolved over the past 30 years. Some preparations have been shown to be unsafe and are now used on a limited basis. There has been progress on limiting the volume required and on taste improvement.

AREAS COVERED IN THIS REVIEW:
This review provides an account of preparations used from 1980 when PEG-based preparations became widely available, until the present day. The review highlights their mechanism of action and principle toxicities. The handling of solutes and solute-free fluid by the colon is also reviewed.

WHAT THE READER WILL GAIN:
The reader will gain a perspective on the factors considered in developing colonic purgatives and the rationale for choosing selected preparations based on patient factors such as age, co-morbidities and concomitant medications.

TAKE HOME MESSAGE:
Although generally safe and effective, colonic purgatives have both acute and permanent toxicities. The safest preparations utilize PEG combined with a balanced electrolyte solution. Limitations of this preparation center on the volume required and poor taste. Alternative formulations are now available; however, those using sodium phosphate have fallen out of favor due to a risk of renal toxicity.

PMID:
21162694
[PubMed – indexed for MEDLINE]
PMCID:
PMC3030244


Can J Gastroenterol. 2006 Nov;20(11):699-710.
Commonly used preparations for colonoscopy: efficacy, tolerability, and safety–a Canadian Association of Gastroenterology position paper.

Barkun A1, Chiba N, Enns R, Marcon M, Natsheh S, Pham C, Sadowski D, Vanner S.
Author information

INTRODUCTION:
The increased demand for colonoscopy, coupled with the introduction of new bowel cleansing preparations and recent caution advisories in Canada, has prompted a review of bowel preparations by the Canadian Association of Gastroenterology.

METHODS:
The present review was conducted by the Clinical Affairs group of committees including the endoscopy, hepatobiliary/transplant, liaison, pediatrics, practice affairs and regional representation committees, along with the assistance of Canadian experts in the field. An effort was made to systematically assess randomized prospective trials evaluating commonly used bowel cleansing preparations in Canada.

RESULTS:
Polyethylene glycol (PEG)-; sodium phosphate (NaP)-; magnesium citrate (Mg-citrate)-; and sodium picosulphate, citric acid and magnesium oxide (PSMC)-containing preparations were reviewed. Regimens of PEG 2 L with bisacodyl (10 mg to 20 mg) or Mg-citrate (296 mL) are as effective as standard PEG 4 L regimens, but are better tolerated. NaP preparations appear more effective and better tolerated than standard PEG solutions. PSMC has good efficacy and tolerability but head-to-head trials with NaP solutions remain few, and conclusions equivocal. Adequate hydration during preparation and up to the time of colonoscopy is critical in minimizing side effects and improving bowel cleansing in patients receiving NaP and PSMC preparations. All preparations may cause adverse events, including rare, serious outcomes. NaP should not be used in patients with cardiac or renal dysfunction (PEG solution is preferable in these patients), bowel obstruction or ascites, and caution should be exercised when used in patients with pre-existing electrolyte disturbances, those taking medications that may affect electrolyte levels and elderly or debilitated patients. Health Canada’s recommended NaP dosing for most patients is two 45 mL doses 24 h apart. However, both safety and efficacy data on this dosing schedule are lacking. Many members of the Canadian Association of Gastroenterology expert panel administer both doses within 24 h, as studied in clinical trials, after careful one-on-one discussion of risks and benefits in carefully selected patients. Safety data on PSMC and combination preparations in North America are limited and clinicians are encouraged to keep abreast of developments in this area.

CONCLUSIONS:
All four preparations reviewed provided effective bowel cleansing for colonoscopy in the majority of patients, with varying tolerability. Adequate hydration is essential in patients receiving the preparations.

PMID:
17111052
[PubMed – indexed for MEDLINE]
PMCID:
PMC2660825