I take the maximum dosage of cymbalta every day. Apparently there's an innumerable list of drugs it's supposed to have an interaction with. One is tramadol, which I also take - I've survived numerous warnings from my pharmicist about the danger of taking those two, but I haven't noticed anything out of the ordinary. Cymbalta helps my mood, no doubt, but as far as the PN goes, I can't really tell if it does anything at all. And there's no generic option for it, so I'm thinking of moving onto something else if it only helps my mood.
Mrs. D is right - you definitely should not take Elavil and Cymbalta at the same time - NEVER take two anti-depressants at the same time. Especially the seratonin reuptakers, etc. Any number of things can happen, and none of them good.