**Core Concept**
Trigeminal neuralgia is a chronic pain condition characterized by sudden, severe, and stabbing pain in the face, typically affecting the trigeminal nerve. The condition is often managed with medications that modulate the excitability of the trigeminal nerve.

**Why the Correct Answer is Right**
The drug of choice for trigeminal neuralgia is carbamazepine, an anticonvulsant medication. Carbamazepine works by blocking voltage-gated sodium channels in the nerve fibers of the trigeminal nerve, thereby reducing the frequency of pain attacks. This action is thought to be mediated through the blockade of T-type calcium channels, which are involved in the generation of neuropathic pain.

**Why Each Wrong Option is Incorrect**
**Option A:** Baclofen is a GABA receptor agonist used primarily for spasticity management. It is not the first-line treatment for trigeminal neuralgia.
**Option B:** Gabapentin is an anticonvulsant medication used in various neuropathic pain conditions. However, it is not as effective as carbamazepine for trigeminal neuralgia.
**Option C:** Amitriptyline is a tricyclic antidepressant used for various pain conditions, including neuropathic pain. However, it is not the preferred treatment for trigeminal neuralgia.

**Clinical Pearl / High-Yield Fact**
Carbamazepine is a first-line treatment for trigeminal neuralgia, but it can cause significant side effects, such as dizziness, drowsiness, and ataxia. Regular monitoring of liver function and complete blood counts is essential when using carbamazepine.

**Correct Answer:** C. Carbamazepine.