title: PETHIDINE COMPARED WITH PETHIDINE PLUS LEVALLORPHAN AND WITH A PLACEBO.
mesh_terms: D000758:Anesthesia; D000773:Anesthesia, Obstetrical; D000776:Anesthesiology; D035843:Biomedical Research; D007275:Injections, Intravenous; D007977:Levallorphan; D008614:Meperidine; D010600:Pharmacology; D010919:Placebos; D014116:Toxicology
chemical_list: D010919:Placebos; D007977:Levallorphan; D008614:Meperidine
keywords: ANESTHESIA, OBSTETRICAL; CLINICAL RESEARCH; INJECTIONS, INTRAVENOUS; LEVALLORPHAN; MEPERIDINE; PHARMACOLOGY; PLACEBOS; TOXICOLOGIC REPORT