**Core Concept**
Haloperidol, a typical antipsychotic, is associated with a rare but serious side effect known as neuroleptic malignant syndrome (NMS). NMS is a life-threatening condition characterized by fever, muscle rigidity, altered mental status, and autonomic dysfunction.

**Why the Correct Answer is Right**
The development of high-grade fever, diarrhea, confusion, and muscle rigidity in a patient on haloperidol treatment is suggestive of neuroleptic malignant syndrome. The pathophysiology of NMS is thought to involve an imbalance between dopamine and acetylcholine in the brain, leading to an excessive release of catecholamines. Treatment of NMS involves immediate discontinuation of the offending agent (in this case, haloperidol) and administration of dantrolene, a direct-acting skeletal muscle relaxant.

* **Option A:** Bromocriptine is a dopamine agonist that can exacerbate NMS by increasing dopamine activity in the brain. It is not the correct choice for treating NMS.
* **Option B:** Metoclopramide is a dopamine antagonist that can also worsen NMS due to its action on the dopamine receptors in the brain. It is not suitable for treating this condition.
* **Option C:** Dantrolene is a direct-acting skeletal muscle relaxant that works by inhibiting calcium ion release from the sarcoplasmic reticulum. It is the correct choice for treating NMS due to its ability to reduce muscle rigidity and hyperthermia.

**Clinical Pearl / High-Yield Fact**
NMS is a medical emergency that requires prompt recognition and treatment. The diagnosis is based on clinical criteria, including the presence of fever, muscle rigidity, altered mental status, and autonomic dysfunction in a patient taking a dopamine antagonist.

**Correct Answer:** C. Dantrolene