Pill with imprint CTI 121 is White, Round and has been identified as Famotidine 20 mg. It is supplied by Carlsbad Technology, Inc.Famotidine is used in the treatment of Erosive Esophagitis; Duodenal Ulcer; Cutaneous Mastocytosis; GERD; Duodenal Ulcer Prophylaxis and belongs to the drug class ...