title: Effects of a single low dose of ranitidine and effervescent antacids on intragastric acidity in healthy volunteers.
abstract: OBJECTIVE
  We hypothesized that a combination of an effervescent antacid and ranitidine could allow immediate and long-lasting increase intragastric acidity. Our aim was to determine the effect of the combined intake of both, of a low dose ranitidine (OTC) and 5 g of antacid on gastric pH.
  
  
  METHODS
  Twenty healthy Helicobacter pylori negative volunteers were enrolled. The study consisted in a fasting 6-hour gastric ph-metric procedure performed in two different periods: baseline (1-hour before drug) and post-drug (5-hours) after oral administration of a single dose of ranitidine (75 mg) plus 5 g of a commercial composed alkaline (sodium bicarbonate, citric acid, sodium carbonate).
  
  
  RESULTS
  While two subjects did not complete the pH-metry analysis due to technical reasons, 18 volunteers were finally assessed. Baseline intragastric pH (1.3 +/- 0.1) (mean +/- SD) rose significantly after administration of the drug (mean pH value for the whole period: 5.1 +/- 0.3; p<0.00001). The pH increased after administration of the study combination and values higher than pH 3 and pH 4 were reached immediately (median time: 27 sec, range: 0-189 and 54 sec, range 27-3,600 sec, respectively). Gastric pH was initially maintained above 4 for 23.0 +/- 5 minutes. The mean time lapsed with pH < 4 during the post-drug period was 96 +/- 17 min (32% ofthe total time).
  
  
  CONCLUSIONS
  Our study confirms the fast and persistent effect produced by the administration of a combination of antacid salts plus low dose of ranitidine. We suggest that the given combination could be effective, fast and safe for sporadic pyrosis or mild grastroesophageal reflux symptoms.
authors.affiliation: Investigación Gastroenterológica Asociación Civil, Buenos Aires, Argentina.
authors.forename: Rafael
authors.initials: R
authors.lastname: Améndola
authors.forename: María Cecilia de los
authors.initials: MC
authors.lastname: Santos
authors.forename: Javier Martinelli
authors.initials: JM
authors.lastname: Massa
authors.forename: Horacio
authors.initials: H
authors.lastname: Vazquez
authors.forename: Edgardo
authors.initials: E
authors.lastname: Smecuol
mesh_terms: D000328:Adult; D000863:Antacids / Q000008:administration & dosage* / Q000494:pharmacology; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000494:pharmacology; D005215:Fasting; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011899:Ranitidine / Q000008:administration & dosage* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000863:Antacids; D000897:Anti-Ulcer Agents; D011899:Ranitidine