title: Comparison of gastric pH with omeprazole magnesium 20.6 mg (Prilosec OTC) o.m. famotidine 10 mg (Pepcid AC) b.d. and famotidine 20 mg b.d. over 14 days of treatment.
abstract: BACKGROUND
  The onset of acid inhibition for proton pump inhibitors is slower than with H2RAs and generally considered to be at a steady-state after 5 days. Thus, little direct comparison data exists between H2RAs and proton pump inhibitors for gastric acid suppression on day 1 of therapy. Furthermore, the durability of their acid suppression has not been systematically compared.
  
  
  OBJECTIVE
  To compare the effects of 20.6 mg omeprazole magnesium o.m. (Ome-Mg 20), famotidine 10 mg b.d. (Fam 10) and famotidine 20 mg b.d. (Fam 20) on intragastric pH on day 1 and throughout 14 days of dosing.
  
  
  METHODS
  The study was a randomized, double-blind, three-dosing regimens, three-period crossover. Healthy adults with frequent heartburn (> or =2 days/week) underwent 24-h gastric pH monitoring on days 0 (baseline), 1, 3, 7 and 14.
  
  
  RESULTS
  Thirty-one subjects were included in the per-protocol analyses. On day 1, the mean percentage time pH > 4 (pH4%) was higher for Ome-Mg 20, 44.6%, than for Fam 10, 36.7% (P = 0.032), and not different from Fam 20, 46.9% (P = 0.541). The pH4% was higher for Ome-Mg 20 than either famotidine regimen on all subsequent monitoring days (P < 0.001). The 24-h area under the mean intragastric pH curve showed a similar pattern. Furthermore, after day 1, Ome-Mg 20 demonstrated an increasing and sustained effect in contrast to a decreasing effect for famotidine, consistent with H2RA tolerance.
  
  
  CONCLUSIONS
  Gastric acid suppression on Ome-Mg 20 mg o.m. over 14 days was comparable with Fam 10 mg b.d. or Fam 20 mg b.d. on day 1, and superior thereafter.
authors.affiliation: Oklahoma Foundation for Digestive Research, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. Philip-miner@ouhsc.edu
authors.forename: P B
authors.initials: PB
authors.lastname: Miner
authors.forename: L D
authors.initials: LD
authors.lastname: Allgood
authors.forename: J M
authors.initials: JM
authors.lastname: Grender
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004812:Epidemiologic Methods; D015738:Famotidine / Q000008:administration & dosage*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage*; D054328:Proton Pump Inhibitors
chemical_list: D000897:Anti-Ulcer Agents; D054328:Proton Pump Inhibitors; D015738:Famotidine; D009853:Omeprazole