Which medicine decreases secretions and prevents laryngospasm?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2024

Pharmacology

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2024

Explanation

Atropine is an anticholinergic (antimuscarinic) drug commonly used as a preanesthetic medication.
Its primary function in this context is to block acetylcholine, which significantly reduces salivary and bronchial secretions.
By creating a drier airway, atropine helps prevent laryngospasm, a dangerous reflex contraction of the vocal cords often triggered by secretions during anesthesia.
Additionally, it blocks vagal stimulation of the heart, preventing severe bradycardia during surgical procedures.

Option A: Morphine is an opioid analgesic. Its primary action is pain relief, and a significant side effect is respiratory depression. It does not have the antisecretory effects needed to prevent laryngospasm.
Option B: Promethazine is an antihistamine with sedative and antiemetic properties. While it possesses some weak anticholinergic effects, it is not potent enough or the standard drug of choice for drying respiratory secretions to prevent laryngospasm.
Option D: This option is incorrect because Morphine and Promethazine do not serve the primary functions of decreasing secretions and preventing laryngospasm.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology of Preanesthetic Medications as background academic context rather than a clinical decision trigger.
Administering atropine pre-operatively is a critical nursing action to ensure airway safety, reducing the risk of life-threatening complications like laryngospasm and aspiration pneumonia during general anesthesia.
Nurses must diligently monitor for common anticholinergic side effects, including tachycardia, dry mouth, blurred vision, and urinary retention, and provide supportive care.
What if? If the patient has a history of narrow-angle glaucoma, atropine is contraindicated as it can dangerously increase intraocular pressure. The nurse must verify this history and alert the anesthesia team, who may choose an alternative like glycopyrrolate.

How to Approach the Question

First, identify the two key therapeutic actions required by the question: 'decreases secretions' and 'prevents laryngospasm'.
Recognize that these actions are primary goals of preanesthetic medication to ensure a safe airway.
Recall the major drug classes and their primary effects. The reduction of bodily secretions is a hallmark effect of anticholinergic drugs.
Evaluate each option based on its primary drug class and mechanism: Morphine (opioid), Promethazine (antihistamine), and Atropine (anticholinergic).
Conclude that Atropine, as a classic anticholinergic agent, is the drug specifically used for this purpose.

Concept Tested & Keywords

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E6 Pharmacology KD Tripathi Essentials 9e Part 2 p. 61-63

E6 Pharmacology Nurses Shanbhag 3e p. 74-76