hi, ive had TN since end of jan 2016 so not long, i am currently on 1200mg, carbemazopine (tegratol) 400mg 3x day, went to see neurologist a wk ago and he changed my tabs to slow release so i dont get the spikes of pain relief then a dip, its more consistant, he also put me on 10mg baclofen, both seem to be doing a better job together. was told 1600mg carbamazapine was top dose. it mite help your friend if they spaced tabs out through the day so they get more consistant relief wether on normal or slow release. i was told to play around with them to find a program that suited me. also u really should see a neaurologist as there might be an underlying caurse for your TN, its not always just because of a blood vessle pushing on a nerve.