One of the following is an antiarrythmic drug :

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

Explanation

Adenosine is an unclassified antiarrhythmic drug used to treat supraventricular tachycardias.
Its primary mechanism is slowing conduction time through the atrioventricular (AV) node, which interrupts the re-entry pathways common in PSVT.
Due to its extremely short half-life (less than 10 seconds), it is administered as a rapid IV push for the acute conversion of PSVT to normal sinus rhythm.

Option A: Spironolactone is a potassium-sparing diuretic and aldosterone antagonist, not an antiarrhythmic.
Option C: Prazosin is an alpha-1 adrenergic blocker, which acts as a vasodilator to lower blood pressure.
Option D: Hydralazine is a direct-acting smooth muscle relaxant that functions as a vasodilator.

Clinical Relevance

Nursing practice connection: Knowing Pharmacology: Antiarrhythmic Drugs helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Administering Adenosine requires specific nursing actions: it must be given as a rapid IV push over 1-2 seconds, followed immediately by a saline flush, due to its very short half-life.
Continuous cardiac monitoring (ECG) is essential during administration, as a brief period of asystole or bradycardia is common and expected before the heart returns to a normal rhythm.
The nurse must have emergency resuscitation equipment (a crash cart) readily available at the bedside before giving Adenosine.

How to Approach the Question

First, identify the core of the question. The question asks you to identify which of the four drugs is an 'antiarrhythmic'.
Next, recall or determine the primary drug class for each option.
Evaluate Spironolactone: This is a diuretic.
Evaluate Adenosine: This is known for treating rapid heart rates, specifically PSVT, classifying it as an antiarrhythmic.
Evaluate Prazosin: This is an alpha-blocker for blood pressure.
Evaluate Hydralazine: This is a vasodilator for blood pressure.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 2 p. 96-98

E6 Pharmacology Nurses Shanbhag 3e p. 122-124

E6 Pharmacology Katzung 16e p. 385-387

Practise the full IGNOU PB. Bsc. Nsg. Entrance-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.