Which of the following adverse effects is not associated with the use of inhaled β-adrenergic agonists?

INI-CET EXAM -2025

Pharmacology

Easy

Appeared in: INI-CET EXAM -2025

Explanation

Inhaled β-adrenergic agonists stimulate β₂ receptors, which activates the sodium-potassium (Na⁺/K⁺) pump.
This pump actively moves potassium from the extracellular fluid (blood) into the cells.
This intracellular shift of potassium leads to a decrease in serum potassium levels, a condition known as hypokalemia.
Therefore, hyperkalemia (an elevated serum potassium level) is the opposite of the actual effect and is not an adverse effect of these drugs.

Option A: Stimulation of β₂-adrenergic receptors on vascular smooth muscle causes relaxation and vasodilation. While the primary target is the bronchi, systemic absorption can lead to peripheral and potentially pulmonary vasodilation.
Option C: This is a common cardiovascular side effect. While β₂-agonists are selective, they can also stimulate β₁ receptors in the heart, especially at higher doses, leading to an increased heart rate and palpitations.
Option D: This is a common neuromuscular side effect. Stimulation of β₂ receptors in skeletal muscle leads to fine tremors, which are often noticeable in the hands.

Visual 1: Diagram - A diagram illustrating the mechanism of action of a β₂-agonist on a bronchial smooth muscle cell, and also showing its systemic effects on the heart (β₁), skeletal muscle (β₂), and potassium shift.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Adverse effects of inhaled β-adrenergic agonists as background academic context rather than a clinical decision trigger.
Nurses should monitor patients receiving β-agonist therapy for tachycardia, palpitations, and tremors, especially when therapy is initiated or doses are increased.
It is crucial to monitor serum potassium levels, particularly in patients receiving high doses, frequent nebulization (e.g., in acute asthma exacerbations), or those also taking diuretics, as the resulting hypokalemia can lead to cardiac dysrhythmias.
What if? If the patient has a pre-existing cardiac condition like an arrhythmia or coronary artery disease, the nurse must be extra vigilant for cardiovascular side effects like palpitations and chest pain, as these drugs increase myocardial oxygen demand.

How to Approach the Question

First, identify the core of the question: it asks for an effect that is NOT associated with inhaled β-adrenergic agonists. This is a negative-framing question.
Recall the primary action of β-agonists (bronchodilation) and their common systemic side effects.
Evaluate each option against your knowledge of the drug class's pharmacology.
Option A (Pulmonary vasodilation): β₂ stimulation causes vasodilation. This is plausible.
Option C (Palpitations): β₁ stimulation is a known side effect causing palpitations. This is a known effect.
Option D (Tremors): β₂ stimulation in skeletal muscle is a classic cause of tremors. This is a known effect.

Concept Tested & Keywords

Concept Tested: Adverse effects of inhaled β-adrenergic agonists
Stem keywords: adverse effects, inhaled β-adrenergic agonists
Lead-in keywords: not associated with
Negative lead-in flag: The question asks to identify the option that is NOT an adverse effect.

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