title: Comparative study of the speed of acid-suppressing effects of oral administration of cimetidine and famotidine.
abstract: OBJECTIVE
  H2 histamine receptor antagonists (H2RAs) are widely used in patients with acid-related diseases, and the onset of antisecretory activity of H2RAs is reported to be faster than that of proton pump inhibitors (PPIs). The aim of this study was to compare the rapidity of onset of antisecretory activity of cimetidine and famotidine when orally administered.
  
  
  METHODS
  Fifteen healthy male Japanese volunteers (five H. pylori-positive and 10 H. pylori-negative) participated in a randomized cross-over study. All subjects were examined three times by ambulatory 6-h pH monitoring (from 17:30 to 23:30) with no medication or oral administration of 400 mg of cimetidine or 20 mg of famotidine. Drugs were administered at 19:30 after eating a standard meal, and plasma concentrations were also examined for 4 h periods.
  
  
  RESULTS
  The plasma concentration of cimetidine increased rapidly after oral administration, while that of famotidine increased gradually. Intragastric pH was increased and percentage time with pH < 4.0 decreased significantly 2 h after administration of either cimetidine or famotidine. There was no statistically significant difference in acid-suppressing effect between cimetidine and famotidine during the short-term post-administration period.
  
  
  CONCLUSIONS
  Rapidity of antisecretory activity did not differ between oral cimetidine and famotidine administered orally.
authors.affiliation: Department of Gastroenterology and Hepatology, Shimane University, School of Medicine, Shimane, Japan. kadachi@med.shimane-u.ac.jp
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Adachi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Komazawa
authors.forename: Takafumi
authors.initials: T
authors.lastname: Mihara
authors.forename: Takane
authors.initials: T
authors.lastname: Azumi
authors.forename: Tomoo
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Katsube
authors.forename: Kenji
authors.initials: K
authors.lastname: Furuta
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kinoshita
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D002927:Cimetidine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D018592:Cross-Over Studies; D015738:Famotidine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D005764:Gastroesophageal Reflux / Q000188:drug therapy / Q000378:metabolism; D006635:Histamine H2 Antagonists / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000188:drug therapy / Q000378:metabolism; D012016:Reference Values; D013270:Stomach / Q000187:drug effects
chemical_list: D006635:Histamine H2 Antagonists; D015738:Famotidine; D002927:Cimetidine