Cut painkiller or carbamazepine?

I have multiple medical conditions as well as TN, and one of them caused a switch from cocodamol to morphine Jan 2014. My TN didn’t like the morphine, and I had to increase my carbamazepine to cope. Now I’m coming off the morphine, very slowly, with permission to add cocodamol back in as a crossover. My TN (the T2 bit - T1 seems to be in remission) is just beginning to make itself felt. I was assuming I’d go back on the cocodamol and reduce the carbamazepine, so I’ve got somewhere to go if/when it gets worse - but might I be better off with higher dose carbamazepine and lower dose painkiller? Which is likely to run out of options sooner? All opinions welcome!