Effects of tablet and effervescent formulations of ranitidine 75 mg and cimetidine 200 mg on gastric acidity and oesophageal acid exposure in healthy humans.
BACKGROUND
Because of their tolerance and safety, low doses of H2-receptor antagonists are now increasingly used in some countries for self-care medication of gastro-oesophageal reflux symptoms.


OBJECTIVE
The purpose of this randomized, double-blind, placebo-controlled, five-way crossover study was to determine and to compare the effects of low doses of ranitidine and cimetidine both on gastric pH and on oesophageal acid exposure.


METHODS
Gastric and oesophageal pH were simultaneously monitored in 20 healthy subjects using two glass pH electrodes, after placebo and single doses of ranitidine 75 mg and cimetidine 200 mg (effervescent and tablet forms), for 4 h before and after a meal.


RESULTS
During the fasting period, median gastric pH rose significantly with both drugs, but more rapidly with the effervescent forms; the oesophageal acid exposure was significantly decreased by all drug regimens. After the meal, although there was no significant difference in gastric pH values, oesophageal acid exposure was significantly decreased in comparison with placebo with both forms of ranitidine (P < 0.05), and also for ranitidine tablets in comparison with cimetidine tablets (P < 0.05).


CONCLUSIONS
Low doses of ranitidine and cimetidine increase gastric pH, with a more pronounced effect for ranitidine. Effervescent formulations of both drugs induce a slightly more rapid initial increase in pH than tablets. Ranitidine demonstrates a more prolonged effect than cimetidine and decreases oesophageal acid exposure monitored after a meal ingested 4 h after the drug intake.
Bruley des Varannes
S
S
Department of Gastroenterology & Hepatology, College of Medicine, University of Nantes, France. bruley@easynet.fr
Duquesnoy
C
C
Mamet
J P
JP
Slama
A
A
Galmiche
J P
JP
Scarpignato
C
C
D000328:Adult; D000704:Analysis of Variance; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000494:pharmacology; D019540:Area Under Curve; D002927:Cimetidine / Q000008:administration & dosage* / Q000494:pharmacology; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004947:Esophagus; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D011899:Ranitidine / Q000008:administration & dosage* / Q000494:pharmacology; D018709:Statistics, Nonparametric
D000897:Anti-Ulcer Agents; D002927:Cimetidine; D011899:Ranitidine