Rhabdomyolysis occurs in -a) Volume depletionb) Cocaine intoxicationc) Hyperphosphatemiad) None of the above

**Core Concept**
Rhabdomyolysis is a serious syndrome characterized by the breakdown of skeletal muscle tissue, leading to the release of myoglobin into the bloodstream. This condition can cause acute kidney injury and requires prompt medical attention.

**Why the Correct Answer is Right**
Rhabdomyolysis often occurs due to direct muscle injury or damage, which can be caused by strenuous exercise, trauma, or certain medications. In the context of the options provided, cocaine intoxication is a known risk factor for rhabdomyolysis due to its vasoconstrictive effects, which can lead to muscle ischemia and subsequent breakdown. The exact mechanism involves the release of catecholamines, such as norepinephrine, which can cause muscle damage.

**Why Each Wrong Option is Incorrect**
**Option A:** Volume depletion can contribute to rhabdomyolysis by reducing blood flow to the muscles, but it is not a direct cause. It is more of a predisposing factor rather than a primary cause.
**Option B:** Cocaine intoxication is indeed a correct answer, so this option is intentionally left blank.
**Option C:** Hyperphosphatemia can occur as a result of rhabdomyolysis due to the breakdown of muscle tissue, but it is not a primary cause of the condition.

**Clinical Pearl / High-Yield Fact**
Cocaine-induced rhabdomyolysis is a well-documented complication of cocaine use, highlighting the importance of considering substance abuse in the differential diagnosis of muscle breakdown and acute kidney injury.

**Correct Answer: B. Cocaine intoxication**