For TN that is not due to a specific cause, treatments that have been helpful include as you mentioned elavil
and lyrica, as well as other medications such as
trileptal, carbamazepine,
and neurontin. The latter 3 were originally developed as a treatment for seizures but have been found very useful in TN. Other less commonly used medications include phenytoin (dilantin), a seizure medication, and antidepressants such as cymbalta.