<prompt> Most potent antiemetic agent used in preoperative periodGlycopyrolateHyoscineAtropineMetochlorpromide  <response>: Commonly used antiemetics in pre-operative period are Hyoscine, Ondansetron, Perinorm.Amongst this Hyoscine is most potent :-Hyoscine is the most potent antiemetic to be used as part of premedication. Fundamental of anaesthesia 