title: Relative analgesic potency of epidural fentanyl, alfentanil, and morphine in treatment of postoperative pain.
mesh_terms: D000368:Aged; D015760:Alfentanil; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D006801:Humans; D007268:Injections, Epidural; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010149:Postoperative Pain / Q000188:drug therapy*; D011897:Random Allocation
chemical_list: D000701:Analgesics, Opioid; D015760:Alfentanil; D009020:Morphine; D005283:Fentanyl