title: A comparison of the analgesics pentazocine and pethilorfan in the relief of pain during labour.
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D007977:Levallorphan; D008614:Meperidine / Q000627:therapeutic use*; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy; D010423:Pentazocine / Q000627:therapeutic use*; D011247:Pregnancy
chemical_list: D007977:Levallorphan; D008614:Meperidine; D010423:Pentazocine