These agents decreases intestinal muscle tone to slow passage of feces:

AIIMS Nagpur NO- 2020

Pharmacology

Medium

Appeared in: AIIMS Nagpur NO- 2020

Explanation

Antidiarrheal opiate agents, such as loperamide and diphenoxylate, act on the mu (μ)-opioid receptors located in the myenteric plexus of the large intestine.
Binding to these receptors inhibits the release of acetylcholine, a neurotransmitter that stimulates propulsive colonic contractions.
This reduction in muscle tone and peristalsis slows the transit of fecal matter through the colon.
The increased transit time allows for more extensive absorption of water and electrolytes from the stool, leading to a firmer consistency and decreased frequency of bowel movements.

Option A: Cathartics are potent stimulant laxatives. They have the opposite effect of what is described; they irritate the intestinal lining to forcefully increase motility and promote rapid evacuation of the bowels.
Option C: Hypertonic solutions, in the context of bowel management, function as osmotic laxatives. They work by drawing a large amount of water into the intestines, which increases the volume of stool and stimulates peristalsis to relieve constipation. This action speeds up, not slows down, the passage of feces.
Option D: Laxatives are a broad category of drugs used to treat constipation by promoting defecation. Their fundamental purpose is to increase or speed up the passage of feces, which is the direct opposite of the action described in the question.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological management of diarrhea and constipation as background academic context rather than a clinical decision trigger.
A critical nursing responsibility is to assess the cause of diarrhea before administering an antidiarrheal. These agents are often contraindicated in diarrhea caused by bacterial infections (like C. difficile) or toxins, as slowing gut motility can delay the clearance of the pathogen and worsen the condition.
Patient education should emphasize adherence to prescribed dosages. Overuse of antidiarrheal agents can lead to rebound constipation, abdominal distention, and in severe cases, paralytic ileus.
What if? If a patient develops diarrhea while taking antibiotics, the nurse should not immediately administer an antidiarrheal. Instead, they should notify the healthcare provider, as this could be antibiotic-associated diarrhea, potentially caused by C. difficile, which requires specific treatment and for which antidiarrheals can be harmful.

How to Approach the Question

First, dissect the question to identify the core physiological action required: 'decreases intestinal muscle tone' and 'slow passage of feces'. This clearly points to an anti-motility or constipating effect.
Next, evaluate each option based on its primary pharmacological purpose.
Eliminate options that have the opposite effect. 'Laxatives' and 'Cathartics' are classes of drugs specifically designed to increase bowel motility and treat constipation.
Analyze the term 'Hypertonic'. In the gastrointestinal context, this refers to osmotic agents that draw water into the bowel, increasing stool volume and stimulating movement. This also contradicts the question.
By elimination, 'Antidiarrheal opiate agents' is the only option designed to slow down gut motility, directly matching the action described in the question.

Concept Tested & Keywords

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