Which of the following is a methylxanthine group of bronchodilators?

Appeared in: DSSSB 14 August 2024

Explanation

Aminophylline is a member of the methylxanthine class of drugs.
Methylxanthines, like theophylline and its derivative aminophylline, cause bronchodilation by inhibiting the phosphodiesterase enzyme, which leads to the relaxation of smooth muscles in the bronchial airways.
These drugs are used in the management of asthma and Chronic Obstructive Pulmonary Disease (COPD).
Aminophylline is a combination of theophylline and ethylenediamine, which makes it more water-soluble and suitable for intravenous administration.

Option A: Terbutaline is not a methylxanthine. It is a selective beta-2 adrenergic agonist.
Option C: Salmeterol is not a methylxanthine. It is a long-acting beta-2 adrenergic agonist (LABA).
Option D: Ipratropium is not a methylxanthine. It is an anticholinergic (muscarinic antagonist) drug.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of Bronchodilator Drugs as background academic context rather than a clinical decision trigger.
Nurses must know the different classes of bronchodilators to administer them safely and educate patients correctly. For instance, SABAs (like Terbutaline) are 'relievers' for acute symptoms, while LABAs (like Salmeterol) are 'controllers' for long-term management and should not be used for acute attacks.
Aminophylline has a narrow therapeutic index, meaning the dose that is effective is close to the dose that is toxic. Nurses must monitor patients closely for signs of toxicity (e.g., nausea, vomiting, tachycardia, seizures) and check serum theophylline levels.
Patient education is critical. A patient on Salmeterol (LABA) must understand it is for prevention and should also have a SABA (like Salbutamol) for acute symptom relief.

How to Approach the Question

First, identify the key term in the question stem, which is 'methylxanthine'.
Recall the major classes of bronchodilator drugs: Beta-2 agonists, anticholinergics, and methylxanthines.
Systematically evaluate each option to determine its drug class.
Option A, Terbutaline, is a well-known beta-2 agonist.
Option B, Aminophylline, is a classic example of a methylxanthine.
Option C, Salmeterol, is another beta-2 agonist, but long-acting.

Concept Tested & Keywords

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E6 Pharmacology Nurses Shanbhag 3e p. 202-204

E6 Pharmacology KD Tripathi Essentials 9e Part 1 p. 269-271

E6 Pharmacology Katzung 16e p. 564-566

Practise the full DSSSB 14 August 2024

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