title: Pain slowly surrenders its secrets as research seeks opiates, new class of analgesics.
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D010146:Pain / Q000188:drug therapy / Q000503:physiopathology; D059408:Pain Management; D012106:Research
chemical_list: D000701:Analgesics, Opioid