Pharmacology · chapter 30 · Gastrointestinal Disorder Drugs
Antidiarrheals
The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.
Key points
Acute versus chronic diarrhea
Diarrhea can be acute (lasting 1–2 days, often due to microorganisms, viruses, or food intolerance) or chronic (lasting weeks, indicating underlying conditions like IBS or Crohn's disease) (Johns Hopkins Medicine, 2023).
Dehydration and bloody stools
Symptoms may include abdominal distress, cramping, bloating, nausea, and urgency. Dehydration is a serious concern, and bloody stools should be reported.
Not with signs of infection
Antidiarrheal treatments aim to slow intestinal motility, but they should not be taken if signs of infection (fever, severe pain, bloody/mucus stool) are present, as they could allow pathogens to multiply.
How opioid-related antidiarrheals work
Opioid-related antidiarrheal medications activate opioid Mu-receptors in the GI tract to slow intestinal motility, allowing more time for absorption of fluid and electrolytes by the colonic mucosal.
Opioid effects at high doses
Caution should be exercised with opioid-related antidiarrheals because, if taken at high doses, clients may experience the typical opioid effects of euphoria or CNS depression.
Why atropine is added
To prevent abuse, low doses of atropine, an anticholinergic, are added to diphenoxylate.
Atropine side effects
Although this combination effectively manages diarrhea, atropine can lead to unpleasant side effects such as blurred vision, urinary retention, dry mouth, constipation, and tachycardia.
Loperamide uses
Loperamide is often used for the symptoms of acute diarrhea, such as traveler’s diarrhea or viral gastroenteritis. It can also be used to manage chronic diarrhea associated with conditions like inflammatory bowel disease and irritable bowel syndrome.
Assess for dehydration
When administering antidiarrheals, the nurse should assess the client for signs and symptoms of dehydration by checking daily weights, skin turgor, and vital signs.
Octreotide when loperamide fails
Octreotide is recommended for clients with CRD that does not respond to loperamide (Krishnamurthi Macaron, 2022).
How to take pancreatin
As a digestive enzyme, pancreatin is always taken with food and with a full glass of water. Pancreatin should be immediately swallowed whole to avoid irritation to the oral mucosa.
Typical adverse effects
Typical adverse effects of common antidiarrheals include constipation, nausea and vomiting, dry mouth, dizziness, drowsiness, and changes in bowel habits including the passage of harder or less-frequent stools.
Diphenoxylate overdose effects
Use of diphenoxylate hydrochloride with atropine sulfate in higher doses than prescribed may lead to opioid and/or anticholinergic effects such as hyperthermia, flushing, tachycardia, hypotonia, lethargy, hallucinations, and repiratory depression.
Report these immediately
Report signs of abdominal distention, severe abdominal pain, fever, palpitations, or bloody diarrhea to the health care provider immediately as these may represent serious adverse effects.
Terms to know
- chemotherapy-related diarrhea (CRD)
- Diarrhea caused by chemotherapy is referred to as chemotherapy-related diarrhea (CRD).
- Diphenoxylate
- Diphenoxylate is a synthetic narcotic that reduces intestinal movement by targeting opioid receptors, effectively stopping diarrhea.
- Pancreatin
- Pancreatin, a medication containing porcine digestive enzymes, is used when the pancreas cannot produce essential enzymes (lipase, amylase, and protease) that are required for proper digestion of fats, carbohydrates, and proteins.
- Octreotide
- Octreotide is a somatostatin analog primarily used for hyperpituitarism disorders, such as acromegaly.
Practice questions
Stuck on select-all-that-apply? How to take them one option at a time.
The graded version needs JavaScript. Every question is below anyway, with the answer and why.
Every question here, with the answer
A client calls about diarrhea with a fever of 102°F, severe abdominal pain, and mucus in the stool. The client wants to take loperamide. What should the nurse advise?
- Do not take an antidiarrheal; contact the health care provider.
- Take loperamide with a caffeinated drink.
- Take loperamide after each loose stool.
- Take double the usual dose to stop it quickly.
Answer: Do not take an antidiarrheal; contact the health care provider.
Antidiarrheals should not be taken with signs of infection such as fever, severe pain, or bloody or mucus stool, because slowing motility can let pathogens multiply; the client should contact the provider. Caffeine increases motility, and extra doses add risk.
A client asks why diphenoxylate is combined with atropine. What is the nurse's best answer?
- Atropine treats the infection causing diarrhea.
- Low-dose atropine is added to prevent abuse.
- Atropine makes the drug work faster.
- Atropine prevents dehydration.
Answer: Low-dose atropine is added to prevent abuse.
Low doses of atropine are added to diphenoxylate to prevent abuse, since atropine counteracts potential euphoria and causes unpleasant effects at higher doses. It does not speed action, prevent dehydration or treat infection.
A client with severe diarrhea is receiving an antidiarrheal. Which assessments help the nurse detect dehydration? Select all that apply.
- Skin turgor
- Pupil size
- Hair texture
- Vital signs
- Daily weights
Answer: Skin turgor, Vital signs, Daily weights
The nurse assesses for dehydration by checking daily weights, skin turgor and vital signs, along with urine and mucous membranes. Pupil size and hair texture are not listed as dehydration checks.
A client is prescribed pancreatin capsules. Which instruction is correct?
- Crush the capsule and sprinkle it on food.
- Take it on an empty stomach.
- Chew it well before swallowing.
- Take it with food and a full glass of water and swallow it whole.
Answer: Take it with food and a full glass of water and swallow it whole.
Pancreatin is taken with food and a full glass of water and swallowed whole to avoid irritating the oral mucosa. It cannot be crushed or chewed, and as a digestive enzyme it is not taken without food.
A client takes diphenoxylate with atropine. Which findings suggest the client has taken more than prescribed? Select all that apply.
- Flushing
- Tachycardia
- Respiratory depression
- Hyperthermia
- Profuse watery diarrhea
Answer: Flushing, Tachycardia, Respiratory depression, Hyperthermia
Higher-than-prescribed doses can cause opioid and anticholinergic effects including hyperthermia, flushing, tachycardia and respiratory depression. The drug slows motility, so profuse diarrhea is not a sign of overdose.
A client on an antidiarrheal reports new abdominal distention and severe abdominal pain. What should the nurse do?
- Report it to the health care provider immediately.
- Reassure the client that this is expected.
- Give another dose of the antidiarrheal.
- Offer a cup of coffee to stimulate the bowel.
Answer: Report it to the health care provider immediately.
Abdominal distention and severe abdominal pain may represent serious adverse effects and are reported immediately. More antidiarrheal could worsen the problem, and caffeine is avoided during diarrhea.
Where every quote comes from
Section 30.2 Antidiarrheals of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.
The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.