Cathartics are medications that :

IGNOU PB. Bsc. Nsg. Entrance-2025

Pharmacology

Easy

Appeared in: IGNOU PB. Bsc. Nsg. Entrance-2025

Explanation

Cathartics, also known as purgatives, are a class of medications specifically designed to promote the evacuation of the bowels.
Their primary mechanism involves stimulating intestinal motility (peristalsis), which propels fecal matter through the colon.
This action results in a more rapid and forceful bowel movement compared to milder laxatives.
They are commonly used to relieve acute constipation or to cleanse the bowel before diagnostic procedures or surgery.

Option A: This is the opposite action of a cathartic. Medications that suppress peristaltic activity are antidiarrheals, used to slow down bowel movements and treat diarrhea.
Option B: Cathartics induce bowel movements and would therefore worsen the symptoms of diarrhea, not treat them. Antidiarrheal agents are used for this purpose.
Option D: This is not the primary mechanism of cathartics. In fact, osmotic cathartics work by drawing more fluid into the intestine. While bulk-forming laxatives absorb water, their main purpose is to increase fecal mass to stimulate peristalsis, which is a form of promoting bowel activity.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Mechanism of Action of Cathartics as background academic context rather than a clinical decision trigger.
Nurses must perform a thorough abdominal assessment before administering a cathartic. Administering it to a patient with a bowel obstruction can lead to bowel perforation, a medical emergency.
Patient education is a critical nursing role. Many patients, especially the elderly, misuse laxatives, leading to laxative dependence, where the bowel loses its natural ability to function without chemical stimulation.
What if? If a patient presents with acute, undiagnosed abdominal pain, a nurse should withhold any ordered cathartics and notify the provider. If the pain is due to appendicitis, a cathartic could cause the appendix to rupture.

How to Approach the Question

First, identify the key term in the question stem: 'Cathartics'.
Recall the pharmacological definition of a cathartic. It is a substance that accelerates or promotes defecation.
Evaluate each option against this core definition.
Option A ('suppress peristaltic activity') and Option B ('treat diarrhoea') describe the opposite effect and indication.
Option D ('absorbs excess fluid') describes the mechanism of only one type of laxative (bulk-forming) and is not the overarching definition of all cathartics.
Option C ('promote bowel activity') is the most accurate and encompassing description of what cathartics do, aligning directly with their definition.

Concept Tested & Keywords

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