A phase III randomized, double-blind, placebo-controlled study evaluating dextromethorphan plus slow-release morphine for chronic cancer pain relief in terminally ill patients.
Dudgeon DJ, Bruera E, Gagnon B, Watanabe SM, Allan SJ, Warr DG, MacDonald SM, Savage C, Tu D, Pater JL. J Pain Symptom Manage. 2007 Apr; 33(4):365-71.