What is the mechanism of action of carbamazepine (used in the treatment of trigeminal neuralgia)?

Carbamazepine (Tegretol) exerts its anticonvulsant and analgesic effects primarily by blocking voltage-gated sodium channels in a use-dependent manner. This reduces the ability of neurons to fire repetitively at high frequencies, which is the underlying mechanism of both seizures and the paroxysmal pain attacks of trigeminal neuralgia. Carbamazepine is the first-line pharmacological treatment for trigeminal neuralgia. Dental relevance: trigeminal neuralgia causes severe, lancinating facial pain along V2 and V3 distributions, and patients may present to dentists thinking they have dental pain. Common dental side effects include xerostomia.