Bulk-Forming Laxatives

Class: Cathartics and Laxatives
ATC Class: A06AC06
VA Class: GA201
CAS Number: 9004-67-5
Brands: Citrucel, Fibercon, Hydrocil, Konsyl, Metamucil

Introduction

Cellulose derivatives (methylcellulose), calcium polycarbophil, malt soup extract, and psyllium preparations are bulk-forming laxatives.

Uses for Bulk-Forming Laxatives

Constipation

Relief of occasional constipation; restore bowel movement regularity.

Initial treatment of choice for simple constipation caused by a low-fiber and/or low-fluid diet.

Bulk-forming laxatives, stool softeners, or mineral oil preferred in conditions in which straining at defecation should be avoided (e.g., MI, vascular diseases, diseases of the anus or rectum, hernias, recent rectal surgery).

Treatment of constipation that occurs following prolonged bed rest or hospitalization.

Treatment of choice for constipation resulting from diminished colonic motor response in geriatric patients; condition is usually due to psychological or physical laxative dependence.

Bulk-forming laxatives or stool softeners are the preferred treatment for constipation occurring during pregnancy or the puerperium.

Not for use when prompt or thorough bowel evacuation is necessary (e.g., poisonings, radiologic examination, bowel surgery).

Diarrhea

Increase the bulk of stools in patients with chronic, watery diarrhea; subjective improvement noted but the total water content of the stool was unchanged.

GI Pain

Reduce intraluminal rectosigmoid pressure and pain in diverticular disease.

Hypercholesterolemia†

Psyllium preparations have been used as an adjunct to dietary therapy to reduce elevated serum total cholesterol, LDL cholesterol, apolipoprotein B (apo B) concentrations and the ratio of LDL-cholesterol to HDL-cholesterol in adults with mild to moderate hypercholesterolemia†.

Bulk-Forming Laxatives Dosage and Administration

Administration

Oral Administration

Administer orally, in conjunction with adequate fluid intake.

For treatment of constipation, administer ≥1 full glass (250 mL) of liquid with each dose. Some manufacturers recommend another full glass of liquid after dose.

When used to increase the bulk of stools in chronic, watery diarrhea, one manufacturer suggests administering 1/3 of a glass (80 mL) of liquid with each dose.

Administer as infrequently as possible at the lowest effective dosage level. Do not use for >1 week unless directed by a clinician.

In patients receiving large dosages, administer in divided doses instead of a single daily dose to reduce the risk of esophageal obstruction.

To minimize side effects, initially administer 0.5–1 dose daily; increase as needed up to 3 doses daily.

Methylcellulose Powder

Fill glass with ≥240 mL (8 ounces) of cold water; level powder and add to water; stir briskly and drink promptly. Chocolate powder may be mixed with milk.

Psyllium Powder

Place dose in empty glass; fill with ≥240 mL of water or other beverage; stir briskly and drink promptly. If mixture thickens, add additional liquid and stir.

Psyllium Capsule

Swallow 1 capsule at a time.

Dosage

Available as calcium polycarbophil; dosage expressed in terms of polycarbophil.