title: Preanesthetic medications.
mesh_terms: D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004329:Droperidol / Q000009:adverse effects; D004341:Drug Evaluation; D006801:Humans; D008614:Meperidine / Q000009:adverse effects; D009020:Morphine / Q000009:adverse effects; D011229:Preanesthetic Medication
chemical_list: D009020:Morphine; D008614:Meperidine; D004329:Droperidol