The object is to provide an excellent pharmaceutical having an anti-Helicobacter pylori activity. Disclosed is a novel pyridine derivative represented by the general formula (I) or a pharmaceutically acceptable salt thereof, which has a potent antibacterial activity against H. pyroli (Helicobacter pyroli): (I) wherein R represents a linear or branched hydroxyalkyl group having 5 to 10 carbon atoms. Examples of the disease which can be prevented/treated by administration of a pharmaceutical agent comprising the compound include gastritis, gastric ulcer, duodenal ulcer, gastric MALT lymphoma, gastric hyperplastic polyp, development of gastric cancer after endoscopic resection of the early stage of gastric cancer and the like.