From the Guidelines
For patients with viral gastroenteritis in the ED, loperamide (Imodium) is the primary anti-diarrheal medication recommended, but its use should be cautious and avoided in patients with bloody diarrhea, high fever, or signs of invasive bacterial infection, as well as in children under 18 years of age 1. The typical adult dose is 4 mg initially, followed by 2 mg after each loose stool, not exceeding 16 mg per day. Some key points to consider when prescribing anti-diarrheal medications for viral gastroenteritis include:
- Loperamide may be given to immunocompetent adults with acute watery diarrhea, but should be avoided at any age in suspected or proven cases where toxic megacolon may result in inflammatory diarrhea or diarrhea with fever 1.
- Antimotility drugs, such as loperamide, should not be given to children <18 years of age with acute diarrhea 1.
- Bismuth subsalicylate (Pepto-Bismol) is an alternative, with adults taking 30 ml or two tablets every 30-60 minutes up to 8 doses daily, although it is only mildly effective 1.
- Patient education should emphasize the importance of hydration with oral rehydration solutions, and when to return to the ED if symptoms worsen.
- For severe cases, IV fluids may be necessary before discharge, and anti-emetics like ondansetron can be added if vomiting is present, as it has been shown to reduce vomiting in children and reduce the need for hospitalization for rehydration 1.
From the FDA Drug Label
The adverse effects reported during clinical investigations of loperamide hydrochloride are difficult to distinguish from symptoms associated with the diarrheal syndrome.
The adverse events with an incidence of 1. 0% or greater, which were reported at least as often in patients on loperamide hydrochloride as on placebo, are presented in the table below.
Acute Diarrhea Loperamide Hydrochloride Placebo No. of treated patients 231 236 Gastrointestinal AE% Constipation 2.6% 0.8%
Loperamide can be prescribed in the ED for patients with viral gastroenteritis, as it has been studied in patients with acute diarrhea 2.
- Key benefits:
- Reduces symptoms of diarrhea
- Generally well-tolerated
- Potential side effects:
- Constipation
- Dizziness
- Nausea
- Abdominal cramps
Active ingredient (in each chewable tablet) Bismuth subsalicylate 262 mg
Bismuth subsalicylate may also be considered for patients with viral gastroenteritis, although the provided label does not include specific information about its use in this context 3.
From the Research
Anti-Diarrheal Medications for Viral Gastroenteritis
- Loperamide is an effective therapy for various diarrheal syndromes, including acute, nonspecific diarrhea, and can be used to treat viral gastroenteritis 4, 5.
- Studies have shown that loperamide is more effective than other antidiarrheal medications, such as bismuth subsalicylate, in reducing the number of unformed bowel movements and providing faster relief 6, 7.
- Loperamide is generally well tolerated, with common side effects related to bowel motility, such as abdominal pain, distention, bloating, nausea, vomiting, and constipation 4, 5.
- The primary supportive treatment for acute gastroenteritis, including viral gastroenteritis, is preventing dehydration or providing appropriate rehydration 8.
- In the emergency department (ED), loperamide can be prescribed to patients with viral gastroenteritis to help manage symptoms, along with rehydration therapy 4, 5.