title: Sources of variation in morphine analgesia in cancer patients with chronic pain.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D009369:Neoplasms; D010148:Intractable Pain / Q000188:drug therapy*
chemical_list: D009020:Morphine