Effects of a single low dose of ranitidine and effervescent antacids on intragastric acidity in healthy volunteers.
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.
Améndola
Rafael
R
Investigación Gastroenterológica Asociación Civil, Buenos Aires, Argentina.
Santos
María Cecilia de los
MC
Massa
Javier Martinelli
JM
Vazquez
Horacio
H
Smecuol
Edgardo
E
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
D000863:Antacids; D000897:Anti-Ulcer Agents; D011899:Ranitidine