**Question:** Which of the following drugs is added along with beta-blockers, in order to eliminate undesirable side effects caused by it while treating Angina?

A. Nitrates
B. Calcium channel blockers
C. Alpha-blockers
D. Angiotensin-converting enzyme inhibitors (ACE inhibitors)

**Core Concept:** Beta-blockers are a class of medications used to treat various cardiovascular conditions, including angina. They work by blocking beta-adrenergic receptors, reducing heart rate, and decreasing myocardial oxygen demand. However, they may have unwanted side effects, such as bronchoconstriction, hypotension, and cold extremities.

**Why the Correct Answer is Right:** The correct answer, B. Calcium channel blockers, is added to beta-blockers to counteract the unwanted side effects. Calcium channel blockers, like nifedipine, verapamil, or diltiazem, act by blocking calcium entry into the cardiac muscle cells, thereby reducing myocardial oxygen demand and minimizing the side effects of beta-blockers.

**Why Each Wrong Option is Incorrect:**

A. Nitrates like isosorbide dinitrate or glyceryl trinitrate are used to relieve anginal pain, not to be combined with beta-blockers to counteract side effects. They work by increasing coronary blood flow and reducing myocardial oxygen demand.

C. Alpha-blockers (e.g., prazosin, doxazosin) are used primarily for hypertension and benign prostatic hyperplasia, not for angina or side effects of beta-blockers. They work by blocking alpha-adrenergic receptors, leading to vasodilation.

D. ACE inhibitors (e.g., enalapril, ramipril) are used to treat hypertension, chronic kidney disease, and heart failure, not to mitigate side effects of beta-blockers. They work by inhibiting the angiotensin-converting enzyme, leading to decreased angiotensin II production, vasodilation, and reduced aldosterone secretion.

**Clinical Pearl:** In clinical practice, calcium channel blockers are often co-prescribed with beta-blockers to optimize treatment for angina patients while minimizing side effects such as hypotension and bradycardia. The combination helps to decrease myocardial oxygen demand and improve cardiac efficiency.