title: Studies of drug interaction.
mesh_terms: D004357:Drug Synergism; D006801:Humans; D006993:Hypnotics and Sedatives; D008614:Meperidine; D010640:Phenothiazines; D010919:Placebos; D011398:Promethazine
chemical_list: D006993:Hypnotics and Sedatives; D010640:Phenothiazines; D010919:Placebos; D008614:Meperidine; D011398:Promethazine