Cimetidine vs ranitidine.
D002927:Cimetidine / Q000627:therapeutic use*; D004381:Duodenal Ulcer / Q000188:drug therapy*; D006801:Humans; D011899:Ranitidine / Q000627:therapeutic use*; D015043:Zollinger-Ellison Syndrome / Q000188:drug therapy
D002927:Cimetidine; D011899:Ranitidine