1. Does therapy with opioids and mexiletine result in better management of postamputation pain than treatment with placebo? Using a randomized, blinded, crossover clinical trial, the effectiveness of therapy with the opioid, morphine, and the oral local anesthetic, mexiletine, will be compared with placebo in the management of phantom and associated stump pain following amputations. The effectiveness of the treatment regimens will be judged by improvements in: a) The intensity of ongoing, stimulus-independent pain using established pain intensity and pain relief scales, b) Stimulus-evoked pain using quantitative sensory tests, and c) Impairment of function using established measures.