Which of the following is a Calcium Channel Blocker (CCB)?

Appeared in: RML MAINS 2025

Explanation

Amlodipine is classified as a dihydropyridine calcium channel blocker (CCB).
CCBs work by blocking the entry of calcium into the smooth muscle cells of blood vessels.
This action causes vasodilation (relaxation of blood vessels), which leads to a decrease in peripheral resistance and lowers blood pressure.
Amlodipine is primarily a vasodilator and has less effect on heart rate compared to other classes of CCBs.

Option A: Atenolol is a beta-blocker, not a calcium channel blocker. It works by blocking beta-1 adrenergic receptors in the heart.
Option C: Enalapril is an Angiotensin-Converting Enzyme (ACE) inhibitor, identifiable by the '-pril' suffix. It works on the renin-angiotensin-aldosterone system.
Option D: Furosemide is a loop diuretic. It reduces blood pressure by promoting the excretion of salt and water, thereby reducing blood volume.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological classification of antihypertensive drugs as background academic context rather than a clinical decision trigger.
Nurses administering CCBs like amlodipine must monitor the patient's blood pressure regularly to assess for effectiveness and watch for hypotension.
Patient education is crucial. Patients should be taught to report symptoms of hypotension like dizziness or lightheadedness, and to change positions slowly.
A common side effect of dihydropyridine CCBs like amlodipine is peripheral edema (ankle swelling). Nurses should assess for this and educate the patient.

How to Approach the Question

First, identify the core of the question, which is to identify a specific class of drug: a Calcium Channel Blocker (CCB).
Next, systematically review each option and recall its pharmacological classification.
Atenolol is a beta-blocker (often ends in '-olol').
Amlodipine is a dihydropyridine CCB (often ends in '-dipine').
Enalapril is an ACE inhibitor (often ends in '-pril').
Furosemide is a loop diuretic.

Concept Tested & Keywords

QOSY9Aq4nbBF973FldnRHu

E6 Pharmacology Katzung 16e pp. 324-326, 292-294

E6 Medicine Harrison 22e Part 2 p. 5-7

Practise the full RML MAINS 2025

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