I've noticed several TN suffers that are taking Tegretol (carbamazepine), have also been prescribed Tramadol for pain. Don't count on your physician to be automatically checking for drug interactions before they prescribe a new medication for you. Always check for yourself. A good website to use is drugs.com, or use Bing or Google to check for drug interactions.
Interactions between your selected drugs

carbamazepine ↔ tramadol
Applies to: Tegretol (carbamazepine), tramadol
GENERALLY AVOID: Concomitant administration of carbamazepine increases tramadolmetabolism, resulting in decreased serum concentrations and decreased efficacy. The suggested mechanism is CYP450 metabolic induction by carbamazepine. In addition, tramadol may increase the risk of seizures.
Concomitant use of tramadol and carbamazepine is not recommended.
As the above example: Taking Tegretol with Tramadol.... I used these as an example because of my own personal experience. Both my neurologist and my internal medicine physician prescribed Tramadol for pain knowing I was also taking Tegretol. It was my second neurologist than told me NEVER to take them together. Together they can cause seizures. Unfortunately, as with everything concerning our disease, do your own research. Most the time we know more than our treating doctors do. Stay informed, ask questions.