Nocturnal gastric acid breakthrough during the administration of rabeprazole and ranitidine in Helicobacter pylori-negative subjects: effects of different regimens.
BACKGROUND
Nocturnal gastric acid breakthrough (NAB) is defined as nocturnal intragastric pH less than 4 for more than 1 h during proton pump inhibitor (PPI) administration. A bedtime dose of an H2 receptor antagonist (H2RA) inhibites NAB, but the efficacy of the H2RA decreases with continuous administration. We carried out the present study to investigate the effect of 14-day H2RA administration on NAB.


METHODS
Ten male volunteers without Helicobacter pylori infection received four different 14-day regimens of rabeprazole and ranitidine (study a, morning dose of 20 mg rabeprazole; study b, morning dose of 20 mg rabeprazole with a single bedtime dose of 150 mg ranitidine only on the last day; study c, continuous 20 mg morning dose of rabeprazole and 150 mg at bedtime; study d, morning and evening doses of 10 mg rabeprazole). Ambulatory 24-h gastric pH monitoring was conducted on the last day of each regimen.


RESULTS
NAB in studies a, b, c, and d was observed in 9, 1, 4, and 4 subjects, respectively, and the longest periods of nocturnal gastric pH at less than 4.0 were 102.5, 14.0, 37.5, and 52.5 min, respectively (study b vs study c, P<0.05).


CONCLUSIONS
The continuous inhibitory effect of ranitidine combined with rabeprazole on nocturnal gastric acid secretion declined during 14-day-long administration in H. pylori-negative subjects. Split dosing of rabeprazole was more effective than the single morning dose for inhibiting nocturnal gastric acid secretion.
Adachi
Kyoichi
K
Second Department of Internal Medicine, Shimane Medical University, 89-1 Enya-cho, Izumo 693-8501, Japan.
Komazawa
Yoshinori
Y
Fujishiro
Hirofumi
H
Mihara
Takafumi
T
Ono
Masahiro
M
Yuki
Mika
M
Kawamura
Akira
A
Karim Rumi
Mohammad Azharul
MA
Amano
Yuji
Y
Kinoshita
Yoshikazu
Y
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage*; D001562:Benzimidazoles / Q000008:administration & dosage*; D019454:Chronotherapy; D018592:Cross-Over Studies; D004359:Drug Therapy, Combination; D005744:Gastric Acid / Q000378:metabolism*; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D009853:Omeprazole / Q000031:analogs & derivatives; D064750:Rabeprazole; D011899:Ranitidine / Q000008:administration & dosage*; D012016:Reference Values
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D064750:Rabeprazole; D011899:Ranitidine; D009853:Omeprazole