What are anti-diarrheal medications?

From the Guidelines

Loperamide (Imodium) is the most effective over-the-counter anti-diarrheal medication for most adults, with a standard dose of 4mg initially, followed by 2mg after each loose stool, not exceeding 8mg per day for over-the-counter use, as recommended by the 2017 Infectious Diseases Society of America clinical practice guidelines 1.

Key Considerations

• The medication works by slowing intestinal motility through opioid receptors in the gut, allowing more water absorption and forming solid stools.
• It's essential to stay hydrated while taking anti-diarrheals by drinking clear fluids.
• These medications should not be used if you have bloody diarrhea, high fever, or severe abdominal pain, as these symptoms may indicate infection requiring different treatment.
• Also, avoid loperamide if you have ulcerative colitis, antibiotic-associated colitis, or bacterial enterocolitis.
• If diarrhea persists beyond 2 days or worsens, seek medical attention.

Additional Options

• Bismuth subsalicylate (Pepto-Bismol) is another option, taken as two tablets or 30ml every 30-60 minutes as needed, not exceeding 8 doses in 24 hours.
• Antimotility drugs, such as loperamide, should not be given to children <18 years of age with acute diarrhea, but may be given to immunocompetent adults with acute watery diarrhea 1.

Important Warnings

• Loperamide may increase the risk of complications from diarrhea, particularly in cases of toxic megacolon, inflammatory diarrhea, or diarrhea with fever 1.
• Antimicrobial agents and antidiarrheal medications administered to people with diarrhea caused by certain infections may increase the risk of severe outcomes, including death 1.

From the FDA Drug Label

Loperamide hydrochloride capsules are indicated for the control and symptomatic relief of acute nonspecific diarrhea in patients 2 years of age and older and of chronic diarrhea in adults associated with inflammatory bowel disease. Loperamide binds to the opiate receptor in the gut wall Consequently, it inhibits the release of acetylcholine and prostaglandins, thereby reducing propulsive peristalsis, and increasing intestinal transit time. Loperamide increases the tone of the anal sphincter, thereby reducing incontinence and urgency.

• Loperamide is an anti-diarrheal medication that works by slowing intestinal motility and affecting water and electrolyte movement through the bowel.
• It is indicated for the control and symptomatic relief of acute nonspecific diarrhea and chronic diarrhea in adults associated with inflammatory bowel disease 2.
• The medication reduces daily fecal volume, increases the viscosity and bulk density, and diminishes the loss of fluid and electrolytes 2.

From the Research

Anti-Diarrheal Medications

• Loperamide is an effective treatment for acute nonspecific diarrhea, providing faster and more effective relief than bismuth subsalicylate 3, 4.
• Loperamide can be used to improve symptoms in patients with watery diarrhea, but should be avoided in patients with bloody diarrhea 5.
• Bismuth subsalicylate may be considered as an alternative treatment for acute diarrhea, but is less effective than loperamide 3, 4.
• Antimotility agents like loperamide may be used as monotherapy or adjunctive therapy for moderate travelers' diarrhea, while antibiotics are recommended for severe cases 6.

Treatment of Acute Diarrhea

• Oral rehydration therapy with early refeeding is the preferred treatment for dehydration caused by acute diarrhea 5.
• Probiotic use may shorten the duration of illness, and antibiotics are effective in treating specific types of bacterial infections, such as shigellosis and campylobacteriosis 5.
• Prevention of acute diarrhea is promoted through adequate hand washing, safe food preparation, access to clean water, and vaccinations 5, 6.

Travelers' Diarrhea

• Travelers' diarrhea is a common problem that affects millions of international travelers to developing countries annually, and can be acquired through ingestion of contaminated food and water 6.
• Loperamide and bismuth subsalicylate may be considered for mild travelers' diarrhea, while antibiotics are recommended for moderate to severe cases 6.
• Pretravel education on hygiene and safe food selection is important in minimizing episodes of travelers' diarrhea 6.