title: Comparative evaluation of subarachnoid morphine & pethidine for post-operative analgesia.
mesh_terms: D000328:Adult; D006801:Humans; D008614:Meperidine / Q000008:administration & dosage*; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010149:Postoperative Pain / Q000188:drug therapy*; D013346:Subarachnoid Space
chemical_list: D009020:Morphine; D008614:Meperidine