**Question:** The drug which does not cause myopathy is:

A. Glucocorticoids
B. Non-steroidal anti-inflammatory drugs (NSAIDs)
C. Calcium channel blockers
D. Beta-blockers

**Core Concept:** Myopathy refers to muscle disease or damage, often caused by medications, toxins, or underlying medical conditions. Medications can directly or indirectly lead to myopathy through various mechanisms, such as direct muscle toxicity, indirect effects on muscle function, or interference with muscle enzyme function.

**Why the Correct Answer is Right:** Beta-blockers (D) are a class of drugs primarily used for cardiovascular conditions like hypertension, angina, and heart failure. While they can cause peripheral neuropathy, myopathy is a less common side effect. Beta-blockers affect the sympathetic nervous system, reducing heart rate, blood pressure, and cardiac output. Unlike glucocorticoids, NSAIDs, and calcium channel blockers, beta-blockers are not directly toxic to muscle cells and do not interfere with muscle enzyme function.

**Why Each Wrong Option is Incorrect:**

A. Glucocorticoids (A) are corticosteroids that are commonly used to treat inflammation, autoimmune diseases, and other conditions. However, they are known to cause myopathy due to their direct toxic effect on muscle cells, leading to muscle weakness, atrophy, and tendon ruptures.

B. Non-steroidal anti-inflammatory drugs (NSAIDs) (B) are a class of medications that reduce inflammation and pain. They can cause myotoxicity, indicating indirect muscle damage due to alterations in renal function, gastrointestinal bleeding, or indirect effects on muscle function.

C. Calcium channel blockers (C) are medications that modulate calcium channels, affecting cardiac and vascular functions. While myopathy can occur with long-term use, it is less common compared to glucocorticoids. Unlike glucocorticoids, calcium channel blockers do not directly cause muscle cell toxicity.

**Core Concept:** Beta-blockers, specifically, are considered safer in terms of causing myopathy compared to the other options.

**Clinical Pearl:** When assessing patients for muscle weakness or tendon ruptures, consider the potential role of medications, particularly glucocorticoids and NSAIDs, as causes of myopathy. In contrast, beta-blockers are generally safer for causing myopathy, although they can still lead to peripheral neuropathy in some cases.