Antidiarrheal Products

Ms. Terrie is a clinical pharmacy writer based in Haymarket,Va.

It is estimated that adults in the United States experience approximately 100 million cases of acute diarrheaper year.¹ Episodes of diarrhea are a common occurrence for many individuals and in general can be classified as acute or chronic. Acute diarrhea is an episode of less than 14 days' duration, while chronic diarrhea lasts more than 4 weeks.^1,2

The causes of acute diarrhea include bacterial, viral, or parasitic infections, while chronic diarrhea is typically related to functional disorders that include intestinal conditions, ie, inflammatory bowel disease, Crohn's disease, or colitis.^1,2,3 Other possible causes of diarrhea include intolerance to certain substances in food, such as artificial sweeteners, lactose, or gluten. In addition, diarrhea may be associated with the use of certain pharmacologic agents, such as antibiotics, antacids containing magnesium, antihypertensive agents with sympatholytic activity, and cytotoxic agents.^1,2 Some individuals may also develop traveler's diarrhea when visiting a foreign country.

Patients should be reminded to immediately contact their health care provider if they experience any of the following symptoms:

• Diarrhea that persists more than 48 hours and worsens
• Diarrhea accompanied by a fever >101?F
• Diarrhea with blood or mucus in the stool
• Any signs of abdominal pain
• Any signs of dehydration (dry mouth, thirst, infrequent urination, dry skin, fatigue, or dizziness)

In general, the majority of episodes of acute diarrhea in the United States are self-limiting and can be treated effectively by implementing various nonpharmacologic measures, such as adequate fluid electrolyte replacement and dietary changes, as well as the use of nonprescription antidiarrheals currently on the market. Pharmacists may often encounter consumers seeking guidance in the proper selection of nonprescription antidiarrheal products. Prior to recommending any product for diarrhea, pharmacists should make certain that self-treatment is appropriate and advise atients to seek medical attention when warranted. Pharmacists should encourage parents to contact their child's pediatrician if they have any concerns, especially if episodes do not show signs of improvement after 24 hours or if the child shows any signs of dehydration. Pharmacists should always assess the patient for possible contraindications and potential drug interactions. Pharmacists can also counsel patients on nonpharmacologic measures, such as maintaining adequate hydration and ways to identify signs of dehydration.

OTC Products

Nonprescription antidiarrheals currently on the market contain either loperamide or bismuth salicylate (Table). In addition, individuals with lactase gastrointestional enzyme deficiency may benefit from the use of lactase enzyme products such as Lactaid caplets and Lactrase capsules. These enzymes may be taken with milk at mealtimes to prevent osmotic diarrhea.²

Loperamide

Examples of Exclusions for Self-Treatment of Diarrhea

• Infants <6 months old
• Individuals showing signs of severe dehydration, especially children
• Individuals with persistent fever
• Females who are pregnant
• Individuals with signs of blood or mucus in the stool
• Individuals with diabetes or severe cardiovascular or renal disease
• Individuals with multiple chronic medical disorders or patients who are immunocompromised

Adapted from reference 2.

Loperamide is indicated for traveler's diarrhea, nonspecific acute diarrhea, or chronic diarrhea associated with inflammatory bowel disease.² The therapeutic effects include reduction of daily fecal volume, increased viscosity and bulk volume, and reduced fluid and electrolyte loss.

Loperamide should not be used by individuals with fecal leukocytes, high fever, or blood or mucus in the stool. Adverse effects associated with loperamide include dizziness and constipation.² Typically, loperamide is not recommended for children <6 years of age unless under the direct supervision of a physician.

Bismuth Subsalicylate

Bismuth subsalicylate is indicated for the management of acute diarrhea including traveler's diarrhea in individuals aged 12 years and older.² Patients should be advised that the use of this agent may cause discoloration of the tongue and stool. The use of this agent should be avoided in the following patient populations:

• Patients with a history of salicylate allergies or those currently taking salicylate products
• Patients with a history of ulcers or coagulation abnormalities
• Patients with medical conditions such as arthritis, diabetes, or gout
• Children or teenagers with or recovering from the flu or chickenpox

Table

References

• Sanaka M, Soffer E. Acute Diarrhea. Cleveland Clinic Web site: www.clevelandclinic.org.
• Walker P. Diarrhea. In: Berardi RR, Kroon LA, McDermott JA, et al, eds. Handbook of Nonprescription Drugs. 15th ed. Washington, DC: American Pharmacists Association; 2006:327-349.
• National Digestive Diseases Information Clearinghouse. Diarrhea. Available at: www.digestive.niddk.nih.gov/ddiseases/pubs/diarrhea.