Review article: the medical management of trigeminal neuralgia.

Trigeminal neuralgia results from disturbances in the trigeminal root entry zone which generate repetitive action potentials. Drugs which relieve the pain of trigeminal neuralgia depressed these potentials. Anticonvulsants which exert this or related effects, and which have been demonstrated to be efficacious in trigeminal neuralgia, include carbamazepine, phenytoin, clonazepam, and valproic acid. Baclofen may act by facilitating segmental inhibition of the trigeminal complex. The mechanism of action of pimozide for treating trigeminal neuralgia is not known. Carbamazepine is suggested as the drug of first choice; baclofen or clonazepam could be added if carbamazepine monotherapy is ineffective. When these fail, monotherapy with phenytoin, pimozide, or valproic acid would be a reasonable next step.