Early effects of oral administration of omeprazole and roxatidine on intragastric pH.
OBJECTIVE
The ideal medication for the treatment of acid-related diseases, e.g., peptic ulcers, stress-related gastric bleeding, functional dyspepsia, and gastroesophageal reflux disease, should have a rapid onset of action to promote hemostasis and relieve the symptoms. The aim of our study was to investigate the inhibitory effects on gastric acid secretion of a single oral administration of a proton pump inhibitor, omeprazole 20 mg, and an H(2)-receptor antagonist, roxatidine 75 mg.


METHODS
Ten Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 6 h after single oral administration of omeprazole 20 mg and roxatidine 75 mg. Each administration was separated by a 7-d washout period.


RESULTS
During the 6-h study period, the average pH after administration of roxatidine was higher than that after administration of omeprazole (median: 4.45 vs. 2.65; P=0.0367). Also during the 6-h study period, a longer duration of maintenance at pH above 2, 5, and 6 was observed after administration of roxatidine 75 mg than after administration of omeprazole 20 mg (median: 90.6% vs. 55.2%, P=0.0284; 43.7% vs. 10.6%, P=0.0125; 40.3% vs. 3.3%, P=0.0125; respectively).


CONCLUSIONS
In Helicobacter pylori-negative healthy male subjects, oral administration of roxatidine 75 mg increased the intragastric pH more rapidly than that of omeprazole 20 mg.
Gastroenterology Division, Yokohama City University School of Medicine, Yokohama 236-0004, Japan.
Hiroshi
H
Iida
Shingo
S
Kato
Yusuke
Y
Sekino
Eiji
E
Sakai
Takashi
T
Uchiyama
Hiroki
H
Endo
Kunihiro
K
Hosono
Yasunari
Y
Sakamoto
Koji
K
Fujita
Masato
M
Yoneda
Tomoko
T
Koide
Hirokazu
H
Takahashi
Chikako
C
Tokoro
Ayumu
A
Goto
Yasunobu
Y
Abe
Noritoshi
N
Kobayashi
Kensuke
K
Kubota
Eiji
E
Gotoh
Shin
S
Maeda
Atsushi
A
Nakajima
Masahiko
M
Inamori
D000328:Adult; D018592:Cross-Over Studies; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008297:Male; D009853:Omeprazole / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology*; D054328:Proton Pump Inhibitors / Q000494:pharmacology*; D055815:Young Adult
D006635:Histamine H2 Antagonists; D010880:Piperidines; D054328:Proton Pump Inhibitors; D009853:Omeprazole; C053742:roxatidine acetate