Hyperosmotic Laxatives

Class: Cathartics and Laxatives
ATC Class: A06AG
VA Class: IR100
CAS Number: 56-81-5
Brands: Babylax, Colace, Colyte, Fleet, GoLYTELY, HalfLytely, MiraLAX, MoviPrep, NuLYTELY, Sani-Supp, Trilyte

Introduction

Glycerin, sorbitol, and polyethylene glycol (PEG 3350) are hyperosmotic laxatives.

Uses for Hyperosmotic Laxatives

Constipation

Glycerin (rectally), sorbitol (rectally), and polyethylene glycol (PEG) 3350 (MiraLAX; orally) may be used for relief of occasional constipation. However, rectal suppositories or enemas should not be used when oral laxatives are effective.

Glycerin and sorbitol may be used to treat constipation occurring during pregnancy or the puerperium; however, bulk-forming laxatives or stool softeners are usually preferred.

May avoid or relieve constipation with proper diet (high fiber content [e.g., bran]), adequate fluid intake, prompt response to the defecation reflex, and exercise.

Avoid use of laxatives in infants and children; treat childhood constipation by counseling parents regarding acceptable variations in the frequency of bowel movements.

Bowel Cleansing

PEG 3350 electrolyte solutions are used to empty the bowel prior to colonoscopy and barium enema radiologic examinations. Glycerin and sorbitol also have been used prior to these procedures, but these laxatives do not always entirely empty the colon.

The American Society of Colon and Rectal Surgeons (ASCRS), American Society for Gastrointestinal Endoscopy (ASGE), and Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) recommend the use of PEG 3350 electrolyte solutions in patients with electrolyte or fluid imbalances (e.g., those with renal or liver insufficiency, CHF, liver failure, advanced liver disease with ascites). These experts also recommend use of PEG 3350 electrolyte solutions for colonic cleansing in infants and children.

Sorbitol as an Adjunct to Sodium Polystyrene Sulfonate

Sorbitol is used orally or rectally to facilitate the passage of sodium polystyrene sulfonate (a resin) through the intestinal tract, prevent constipation caused by the resin, aid in potassium removal, and improve the palatability of the resin.

Hyperosmotic Laxatives Dosage and Administration

General

• Prior to bowel cleansing, provide a copy of the patient information provided by the manufacturer containing careful instructions on the proper methods of reconstitution and administration of the laxatives.

Administration

Administer sorbitol rectally; may administer orally when used as an adjunct to sodium polystyrene sulfonate.

Administer glycerin solution and suppositories rectally.

Administer PEG 3350 electrolyte solutions orally or through a nasogastric tube.

Oral or Nasogastric Administration (PEG 3350, PEG 3350 with Electrolytes)

Reconstitution

When used for constipation, reconstitute PEG 3350 powder for oral solution (MiraLAX) with 120–240 mL of water (cold, room temperature, or hot).

When used for bowel cleansing, reconstitute PEG 3350 powder (with electrolytes) for oral or nasogastric solution with the appropriate amount of lukewarm water as directed by the manufacturer.

Shake solution vigorously until ingredients are dissolved; additional ingredients (flavorings o...