A comparative study of the early effects of tenatoprazole 40 mg and esomeprazole 40 mg on intragastric pH in healthy volunteers

BACKGROUND: Tenatoprazole is a novel proton pump inhibitor with a seven-hour plasma half-life. AIM: To compare the effects of tenatoprazole 40 mg and esomeprazole 40 mg on intragastric acidity during the first 48 h in healthy volunteers. METHODS: This randomized two-period crossover study included 24 Helicobacter Pylori-negative subjects; tenatoprazole 40 mg or esomeprazole 40 mg daily were given before breakfast for two consecutive days, with a 2-week wash-out between the administration periods. Intragastric pH was monitored for 48 h. RESULTS: Over 48 h, tenatoprazole 40 mg exerted a more potent acid inhibition than esomeprazole 40 mg (median pH: 4.3 vs. 3.9, P < 0.08; per cent of time above pH 4: 57% vs. 49%, P < 0.03; proportion of subjects with at least half of the time above pH 4: 71% vs. 46%). These differences resulted from better night-time acid control with tenatoprazole 40 mg than esomeprazole 40 mg (first night median pH: 4.2 vs. 2.9, P < 0.0001; second night: 4.5 vs. 3.2, P < 0.0001). The duration of nocturnal acid breakthroughs was significantly reduced during both nights. In contrast, no significant difference was detected during the daytime periods between both regimens. CONCLUSION: Over the first 48 h, tenatoprazole 40 mg achieves a better overall and night-time control of gastric pH than esomeprazole 40 mg. The translation of better early control of acidity into clinical benefits deserves further studies.     

Comparison of the effects of fasting morning, fasting evening and fed bedtime administration of tenatoprazole on intragastric pH in healthy volunteers: a randomized three-way crossover study

BACKGROUND: The effectiveness of proton pump inhibitors is influenced by meals and administration time. AIM: To compare the effects on intragastric acidity of times of dosing of tenatoprazole, a novel imidazopyridine-based proton pump inhibitor with a prolonged plasma half-life. METHODS: This randomized three-period crossover study included 12 Helicobacter pylori-negative healthy subjects, who received tenatoprazole 40 mg either fasting at 7.00 AM, fasting at 7.00 PM or fed at 9.30 PM for 7 days, with a 2-week washout between periods. Twenty-four hour intragastric pH was monitored on day 7 of each period. RESULTS: On day 7, median 24-h pH was 4.7, 5.1 and 4.7 after breakfast, dinner and bedtime dosing, respectively (P = 0.11), whereas night-time pH was 4.2, 5.0 and 4.4 (P = 0.13). The mean 24-h percentage of time over pH 4 was 62, 72 and 64 after breakfast, dinner and bedtime dosing, respectively (N.S.), and 54, 68 and 56 during night-time (P = 0.06). Nocturnal acid breakthrough incidence decreased from 100% at baseline to 83%, 55% and 75% after 7.00 AM, 7.00 PM and 9.30 PM dosing, respectively (P = 0.18), and its mean duration dropped from 6.2 to 2.8, 1.0 and 2.2 h, respectively (P < 0.05). CONCLUSION: Seven-day administration of tenatoprazole provides a prolonged duration of acid suppression, especially during the night-time, with little effect of food or time of dosing.     

Comparison of the effects of immediate-release omeprazole powder for oral suspension and pantoprazole delayed-release tablets on nocturnal acid breakthrough in patients with symptomatic gastro-oesophageal reflux disease

BACKGROUND: Many patients treated with a proton-pump inhibitor for gastro-oesophageal reflux disease or erosive oesophagitis still have substantial night-time gastric acidity. A previous trial of a new immediate-release omeprazole oral suspension suggested that nocturnal gastric acidity could be more effectively controlled with a bedtime dose of immediate-release omeprazole than with a delayed-release proton-pump inhibitor administered before dinner or at bedtime. AIM: To compare the ability of immediate-release omeprazole with pantoprazole to control nocturnal gastric acidity, when they were dosed once daily and twice daily. METHODS: Thirty-six patients with nocturnal gastro-oesophageal reflux disease symptoms received immediate-release omeprazole and pantoprazole in this open-label, randomized-crossover trial. Median gastric pH, the percentage of time with gastric pH > 4 and the percentage of patients with nocturnal acid breakthrough, were evaluated with 24-h pH monitoring. RESULTS: Repeated once daily (bedtime) dosing with immediate-release omeprazole suspension produced significantly better nocturnal gastric acid control than repeated once daily (predinner) or twice daily (prebreakfast and bedtime) dosing with pantoprazole delayed-release tablets (median pH: 4.7 vs. 2.0 and 1.7; percentage of time pH > 4: 55 vs. 27 and 34; nocturnal acid breakthrough: 53 vs. 78 and 75). Twice daily dosing (prebreakfast and bedtime) with immediate-release omeprazole 20 and 40 mg achieved the best night-time control of gastric acidity. Repeated once daily bedtime dosing with immediate-release omeprazole 40 mg and twice daily dosing with pantoprazole 40 mg gave similar 24-h pH control. No safety issues were associated with either drug in this trial. CONCLUSIONS: Dosed once daily at bedtime, immediate-release omeprazole reduced nocturnal gastric acidity to a degree not observed with once daily dosing of delayed-release proton-pump inhibitors.     

Comparison of the effects of immediate-release omeprazole oral suspension, delayed-release lansoprazole capsules and delayed-release esomeprazole capsules on nocturnal gastric acidity after bedtime dosing in patients with night-time GERD symptoms

BACKGROUND: Gastro-oesophageal reflux disease (GERD) patients on proton pump inhibitors before breakfast or dinner have acid recovery at night. Bedtime immediate-release omeprazole (IR-OME) demonstrated better control of nocturnal pH than pantoprazole before dinner. AIM: To compare repeated once daily bedtime dosing of IR-OME, lansoprazole and esomeprazole on nocturnal gastric acidity. METHODS: Open-label, randomized, crossover study enrolling 54 patients with nocturnal GERD symptoms comparing IR-OME, lansoprazole and esomeprazole at steady state for nocturnal acid breakthrough (NAB), percentage of time with gastric pH > 4 and median gastric pH. RESULTS: Onset of nocturnal acid control with IR-OME was rapid. During the first half of the night, percentage of time with gastric pH > 4 and median gastric pH were significantly higher after IR-OME compared to esomeprazole or lansoprazole (P < 0.001, both comparisons). Over the 8-h night-time period, acid control with IR-OME was significantly better than lansoprazole (P < 0.001), and comparable to esomeprazole. IR-OME reduced NAB compared with esomeprazole and lansoprazole (61% vs. 92% and 92%; P < 0.001, both comparisons). CONCLUSIONS: Bedtime IR-OME provided more rapid control of night-time gastric pH and decreased NAB compared with esomeprazole and lansoprazole. Nocturnal acid control with IR-OME was superior to lansoprazole and comparable to esomeprazole. Bedtime dosing with IR-OME may be effective for patients with night-time heartburn.     

Effect of splitting the dose of esomeprazole on gastric acidity and nocturnal acid breakthrough

BACKGROUND: Twice-daily dosing is increasingly used to improve gastric acid control, although not all proton-pump inhibitors are more effective when doses are split. Standard dose esomeprazole provides better gastric acid control than other standard dose proton-pump inhibitors. AIMS: To compare the effect of standard dose esomeprazole (1 x 40 mg) with 20 mg b.d. on gastric acidity. METHODS: Thirteen healthy subjects participated in this crossover study, receiving esomeprazole 2 x 20 mg and 1 x 40 mg for 7 days in random order with a washout period of at least 7 days. Gastric 24-h pH was measured on days 1, 2 and 6. RESULTS: Median gastric 24-h pH was higher during 2 x 20 mg esomeprazole on day 2 (P < 0.01), no differences were detected on day 6. Night-time gastric acid suppression was significantly improved by 2 x 20 mg esomeprazole on all study days (P < 0.05). Nocturnal acid breakthrough was observed on all study days in subjects receiving 1 x 40 mg, but in only 85% (first night), 64% (second night), and 45% of subjects (sixth night) with 2 x 20 mg (P < 0.05). CONCLUSION: Splitting the esomeprazole dose improves initial acid suppression, this effect starts at the first night. Maximal benefit is achieved on day 2, while the effect on night-time acid control is detectable during the entire first week of treatment.     

The pharmacodynamics and pharmacokinetics of S‐tenatoprazole‐Na 30 mg, 60 mg and 90 mg vs. esomeprazole 40 mg in healthy male subjects

Aliment Pharmacol Ther 31 , 648–657

Summary

Background Racemic tenatoprazole 40 mg/day provides more prolonged acid suppression than esomeprazole 40 mg/day. Aim To compare pharmacodynamic and pharmacokinetic profiles of tenatoprazole and esomeprazole. Methods A single‐centre, double‐blind, double‐dummy, randomized, 4‐way, cross‐over study was conducted in 32 healthy male subjects. S‐tenatoprazole‐Na 30, 60 or 90 mg, or esomeprazole 40 mg was administered once daily for 5 days with 10‐day washout intervals. The 24‐h intragastric pH was recorded at baseline and on day 5 of each period. Results On day 5, median pH (5.34 ± 0.45 and 5.19 ± 0.52 vs. 4.76 ± 0.82, respectively, P < 0.002) and percentage time with pH > 4 (80 ± 11 and 77 ± 12, vs. 63 ± 11 respectively, P < 0.0001) for 24‐h were higher with S‐tenatoprazole‐Na 90 mg and 60 mg than esomeprazole. In nocturnal periods, S‐tenatoprazole‐Na 90 mg, 60 mg and 30 mg were superior to esomeprazole with regard to median pH (5.14 ± 0.64, 4.94 ± 0.65, 4.65 ± 0.86 and 3.69 ± 1.18 respectively, P < 0.0001) and percentage time with pH > 4 (77 ± 12, 73 ± 17, 64 ± 17 and 46 ± 17 respectively, P < 0.0001). Proportion of subjects with nocturnal acid breakthrough with S‐tenatoprazole‐Na 90 mg, 60 mg and 30 mg was significantly less than with esomeprazole (54.8, 43.3, 56.7 and 90.3 respectively, P < 0.04). The proportion of subjects with >16 hrs with pH >4 was significantly higher with S‐tenatoprazole‐Na 90 mg and 60 mg than with esomeprazole (87.1%, 83.3% and 41.9% respectively, P < 0.02). Conclusions S‐tenatoprazole‐Na produced significantly greater and more prolonged dose‐dependent 24‐h and nocturnal acid suppression than esomeprazole. S‐tenatoprazole‐Na may provide greater clinical efficacy compared with current PPIs for patients with ineffective once‐daily therapy.     

Twenty-four-hour intragastric acidity and plasma gastrin during 3-month treatment with omeprazole in healthy subjects

Background : Prolonged treatment with omeprazole 20 or 40 mg/day is sometimes required, especially for severe oesophagitis. However, information about long-term effects on intragastric acidity and plasma gastrin response with such drug regimens is scarce.
Methods : Sixteen healthy subjects (11 men, 5 women, mean age 29 years) randomly received either 20 or 40 mg of omeprazole once daily (at 08.00 h) for 3 months. Gastric pH was recorded every 6 s for 24 h from noon to noon under standardized conditions, and blood samples were collected hourly in order to determine the 24-h plasma gastrin response on day 0 (pre-entry), day 7, day 28 and day 90.
Results : From day 0 to day 7, 24-h median pH increased from 1.7 to 4.6 and mean percentage of time at pH < 4 decreased from 89% to 35% with omeprazole 20 mg. Respective values with omeprazole 40 mg were 1.9 to 4.3, and 89% to 34%. Inhibition of gastric acidity remained unchanged during the 3 months of treatment. Despite similar effects on the basis of 24-h analysis, the decrease in daytime acidity was slightly higher with omeprazole 40 mg than with omeprazole 20 mg. Twenty-four-hour integrated plasma gastrin significantly increased with both drug regimens between day 0 and day 7 ( P  < 0.01), and between day 7 and day 28 ( P  < 0.01) with omeprazole 40 mg; there was no significant increase between day 28 and day 90 with either of the drug regimens.
Conclusion : Omeprazole 20 and 40 mg/day provides long-term stable acid suppression with a progressive increase in gastrin response, stabilizing after 2 months of treatment.     

Control of intragastric acidity with over-the-counter doses of ranitidine or famotidine

BACKGROUND: Histamine H2-receptor antagonists are available over the counter for the treatment of heartburn. AIM: To compare the effects of low doses of ranitidine and famotidine on intragastric acidity in a three-way crossover study. METHODS: Healthy subjects (12 male, 12 female) were dosed on three occasions with single oral doses of placebo, ranitidine, 75 mg, and famotidine, 10 mg, 1 h after lunch. The pH of gastric aspirates was then measured for 20 h. Subjects ate standard meals and snacks. Analysis of variance was used to determine the statistical significance of differences in acidity (mmol/L) during the day (12.30-22.30 hours) and night (22.30-08.30 hours). RESULTS: Ranitidine and famotidine were superior (P < 0.05) to placebo in decreasing acidity for daytime and night-time intervals. There were no significant differences in mean gastric acidity between ranitidine and famotidine during the daytime (11.37 mmol/L vs. 13.42 mmol/L, respectively) and night-time (23.57 mmol/L vs. 24.74 mmol/L, respectively). Intragastric acidity after ranitidine was significantly lower than that after famotidine in the first 2.5-h period following dosing (4.32 mmol/L vs. 9.28 mmol/L; P < 0.05). CONCLUSIONS: Lunchtime doses of ranitidine and famotidine decreased acidity during day- and night-time periods. The effect of ranitidine was significantly greater for the first 2.5 h after dosing.     

Eradication of Helicobacter pylori increases nocturnal intragastric acidity during dosing with rabeprazole,omeprazole, lansoprazole and placebo

BACKGROUND: The eradication of Helicobacter pylori decreases the antisecretory activity of omeprazole and lansoprazole. Rabeprazole is a potent proton pump inhibitor that may not be affected as greatly by H. pylori status. AIM: To compare the effect of H. pylori eradication on intragastric acidity and plasma gastrin during dosing with lansoprazole, omeprazole, rabeprazole and placebo. METHODS: Twenty-four healthy H. pylori-infected volunteers were studied on day 7 of dosing with placebo, lansoprazole 30 mg, omeprazole 20 mg and rabeprazole 20 mg, before and at least 5 weeks after H. pylori eradication. On each occasion, the 24-h intragastric acidity was measured by gastric aspiration. Plasma gastrin concentrations were measured hourly from 08.00 to 13.00 h. RESULTS: Sixteen subjects completed the study. For all three drugs and placebo, H. pylori eradication increased intragastric acidity, particularly nocturnal acidity, and decreased plasma gastrin. There were no differences between the three drugs with respect to 24-h acidity, percentage of time pH > 4 or 5-h plasma gastrin, either before or after H. pylori eradication. Before eradication, the percentage nocturnal time at pH > 3 was significantly greater during rabeprazole than during lanso-prazole dosing. CONCLUSIONS: The increase in intragastric acidity seen after H. pylori eradication during dosing with proton pump inhibitors is a drug-class effect, particularly affecting nocturnal acid control. This is related to increased spontaneous intragastric acidity after H. pylori eradication.     

Nocturnal gastric acidity and acid breakthrough on different regimens of omeprazole 40 mg daily

Background

On chronic intake of omeprazole, most healthy volunteers and patients still have nocturnal acid breakthrough (NAB), defined as night-time periods with gastric pH < 4.0 lasting for longer than 1 h. Gastro-oesophageal reflux during NAB may be particularly injurious to the oesophageal mucosa, contributing to the chronic lesions complicating the condition.

Aim

To compare the effect of three different dosing regimens of omeprazole 40 mg daily with regard to suppressing nocturnal gastric acidity and avoiding NAB.

Methods

Eighteen healthy volunteers were given three different regimens of omeprazole for 7 days each in randomized order: 40 mg before breakfast (qAM), 40 mg before dinner (qPM) and 20 mg before breakfast and dinner (b.d.). On day 7, 24-h intragastric and intra-oesophageal pH-metry was performed. Tracings were analysed for the period from 22.00 h until 06.00 h with regard to the percentage of time at which gastric pH was below 4.0, 3.0 and 2.0, and also the occurrence and duration of NAB.

Results

Nocturnal acid breakthrough was significantly more common on qAM than on qPM and b.d. (P < 0.05) dosing. The percentage of time gastric pH was less than 4.0 overnight was significantly lower on qPM (median 31.3) and b.d. (median 20.5) than on qAM (median 66.3) dosing (P = 0.01 and P < 0.02, respectively). A pH threshold of 3 and 4 showed the same differences, as did median 24-h gastric pH. Daytime acidity was not significantly different.

Conclusions

In healthy volunteers, dinner time or split dosing of omeprazole 40 mg daily is significantly more effective than dosing before breakfast in preventing NAB and controlling gastric acidity. These regimens should be preferred in patients in whom suppression of nocturnal gastric acidity is desirable.

     

Control of intragastric pH with omeprazole 20 mg, omeprazole 40 mg and lansoprazole 30 mg

BACKGROUND: Single daily doses of proton pump inhibitors, omeprazole and lansoprazole provide effective acid suppression and equal healing and symptom relief in patients with GERD. Despite this, controversy exists as to the efficacy of available proton pump inhibitors in the control of gastric acidity. AIM: To assess the efficacy of omeprazole 20 mg vs. lansoprazole 30 mg and omeprazole 40 mg vs. lansoprazole 30 mg in intragastric pH control. METHODS: Study I: 12 Helicobacter pylori-negative volunteers (mean age 33 years) were treated with omeprazole 20 mg and lansoprazole 30 mg in random order before breakfast for 7 days. Study II: 24 subjects (mean age 36 years) were similarly treated with omeprazole 40 mg and lansoprazole 30 mg for 7 days after a baseline pH study. One week washout was allowed between studies. Subjects had the same meal on each study day. On day seven, a 24-h intragastric pH study was performed. The percentage time for which gastric pH > 4 was analysed (Gastrosoft, Synectics Medical Inc.) and expressed as mean +/- s.d. RESULTS: (1) Omeprazole 20 mg and lansoprazole 30 mg showed no significant difference in the percentage time for which gastric pH > 4 in the daytime and night-time periods. (2) The percentage time for which pH > 4 with omeprazole 40 mg was significantly greater than lansoprazole 30 mg in both daytime (61 +/- 19% vs. 48 +/- 14%, P < 0.001), and night-time periods (34 +/- 21% vs. 26 +/- 14%, P < 0.05). (3) A large inter-subject variation existed in both studies. (4) In 10 subjects who participated in both studies, omeprazole 40 mg showed a significantly higher percentage time for which pH > 4 in the daytime (69 +/- 18% vs. 51 +/- 15%, P=0.015) than omeprazole 20 mg. CONCLUSION: These pH data support the therapeutic equivalency of FDA approved doses of omeprazole and lansoprazole.     

Rebound hypersecretion after H2-antagonist withdrawal—a comparative study with nizatidine, ranitidine and famotidine

Our previous study demonstrated rebound nocturnal acid hypersecretion after a 4-week course of nizatidine. Nocturnal acid output was increased by 77% two days after discontinuing treatment compared with pretreatment values. To confirm this effect with other H2-blockers we assessed daytime intragastric pH, fasting and meal-stimulated plasma gastrin and nocturnal acid output in 9 duodenal ulcer patients in remission before, during and two days after treatment with three different drugs. Each patient received 4-week courses of 300 mg ranitidine, 40 mg famotidine or 300 mg nizatidine, taken at 20.00 hours in randomized order with a 'washout' period of 4 weeks between each course of drug. Median nocturnal acid output (mmol/10 h) decreased during treatment with ranitidine to 3 (range 0-17), famotidine to 4 (1-12) and nizatidine 6 (0-40) compared with the respective pre-treatment values, 49 (20-126; P less than 0.01), 52 (22-105; P less than 0.01) and 32 (23-114; P less than 0.01). Two days after discontinuing treatment nocturnal acid output was increased after ranitidine at 77 (28-237; P less than 0.04) and after nizatidine at 64 (17-130; P less than 0.05) compared with pre-treatment values. There was no significant change in nocturnal acid output after famotidine at 57 (27-107) compared with the pre-treatment value. There was no change in daytime intragastric pH with any drug during or after treatment compared with the pre-treatment values. Fasting and meal-stimulated plasma gastrin concentrations were increased on the final treatment day with ranitidine and famotidine but had returned to pretreatment levels two days after treatment. The rebound acid hypersecretion may contribute to the high ulcer relapse rate after discontinuation of H2-receptor antagonists.     

A placebo-controlled study to assess the effects of 7-day dosing with 10, 20 and 40 mg rabeprazole on 24-h intragastric acidity and plasma gastrin in healthy male subjects

AIM: To compare the effects of rabeprazole 10, 20 and 40 mg o.d. on 24-h intragastric acidity and plasma gastrin concentration in a randomized, double-blind placebo-controlled trial. METHODS: Twenty-four healthy male volunteers were studied on the 7th day of morning dosing with either placebo or rabeprazole 10, 20 or 40 mg in a crossover fashion. On day 7, hourly intragastric acidity was measured for 24 h from 08.00 hours by gastric aspiration. Plasma gastrin concentrations were also measured hourly from 08.00 to 24.00 hours, and 2-hourly thereafter. RESULTS: Compared with placebo, rabeprazole 10, 20 and 40 mg produced significant dose-related decreases in intragastric acidity (median 24-h integrated acidity=697, 186, 129 and 82 mmol h/L, respectively). This was associated with significant elevation of plasma gastrin concentration (median 24-h integrated gastrin=141, 1184, 1484 and 1763 pmol.h/L, respectively). Rabeprazole 40 mg resulted in significantly decreased acidity compared with both 10 and 20 mg, and in longer times for which intragastric pH was maintained at > 3 (19. 2 h vs. 17.3 h and 17.5 h) and > 4 (17 h vs. 14.2 h and 15.2 h), but was accompanied by significantly increased plasma gastrin. There was a consistent trend for greater antisecretory activity for 20 mg compared with 10 mg, but these differences did not reach statistical significance. The interindividual variability in antisecretory response was greatest with 10 mg. CONCLUSIONS: Rabeprazole 10, 20 and 40 mg produce significant, profound dose-related inhibition of gastric acid secretion. Taking into account reciprocal increases in plasma gastrin and the interindividual variation in antisecretory response, 20 mg appears to be the preferred dose for routine clinical use.     

Helicobacter pylori infection influences nocturnal gastric acid breakthrough

BACKGROUND: Nocturnal gastric acid breakthrough is defined as night-time periods when gastrin pH falls below 4.0 for greater than 1h during administration of a proton pump inhibitor. This phenomenon is a serious problem for patients who require strict control of their gastric acid secretions. AIM: To investigate the prevalence of nocturnal gastric acid breakthrough in Japanese subjects during administration of rabeprazole, and to clarify the relationship between Helicobacter pylori infection and nocturnal gastric acid breakthrough. METHODS: Thirty-one normal male volunteers were examined by ambulatory 24 h gastric pH monitoring four times: without medication, after a morning or an evening dose of 20 mg rabeprazole, and after administration of an H2-receptor antagonist at bedtime, in addition to the morning dose of rabeprazole. H. pylori infection was determined by the 13C-urea breath test and an assay for serum anti-H. pylori antibody. RESULT: Nocturnal gastric acid breakthrough was observed in 12 patients (39%) after the morning dose of 20 mg rabeprazole. In all cases, nocturnal gastric acid breakthrough was inhibited completely by administration of the H2-receptor antagonist at bedtime. Only one patient with nocturnal gastric acid breakthrough had H. pylori infection. CONCLUSION: The absence of H. pylori infection appears to be closely related to the occurrence of nocturnal gastric acid breakthrough during dosing with a proton pump inhibitor.     

Pharmacodynamic effects of single doses of rabeprazole 20 mg and pantoprazole 40 mg in patients with GERD and nocturnal heartburn

BACKGROUND: Rabeprazole and pantoprazole are both used for symptomatic treatment of gastro-oesophageal reflux disease (GERD). Speed and duration of acid suppression and intensity of effect after a single dose may be important pharmacodynamic properties in clinical use. AIM: To compare antisecretory effects of single doses of rabeprazole and pantoprazole in patients with GERD and a history of nocturnal heartburn. METHODS: An open-label, randomized, two-way crossover, clinical pharmacology study was conducted. Twenty-nine Helicobacter pylori-negative GERD patients (17 men, mean age 44 years), with a history of nocturnal heartburn (mean frequency 4.7 episodes/week), received a single dose of rabeprazole 20 mg or pantoprazole 40 mg, with a 14-day 'washout'. Intragastric pH was recorded continuously from 24 h before to 24 h after dosing. RESULTS: Mean area under the intragastric pH-time curve (AUC) was significantly higher after dosing with rabeprazole 20 mg than with pantoprazole 40 mg in all time intervals analysed, including night (P 3 and >4 was significantly greater after rabeprazole than pantoprazole in all time intervals (P 相似文献   

Effects of a single dose of rabeprazole 20 mg and pantoprazole 40 mg on 24‐h intragastric acidity and oesophageal acid exposure: a randomized study in gastro‐oesophageal reflux disease patients with a history of nocturnal heartburn

Aliment Pharmacol Ther 31 , 991–1000

Summary

Background Nocturnal heartburn is common in patients with gastro‐oesophageal reflux disease (GERD). Aim To compare the effects of single doses of rabeprazole 20 mg and pantoprazole 40 mg on 24‐h intragastric acidity and oesophageal acid exposure (OAE). Methods A total of 52 subjects with GERD and a ≥6‐month history of heartburn were randomized into a blinded, 2 × 2 crossover trial. Subjects’ intragastric pH was monitored in two 48‐h study periods with 6‐ to 13‐day washout between periods. Patients received placebo on day 1, a single dose of rabeprazole 20 mg or pantoprazole 40 mg on day 2, and standardized meals throughout. Results The mean percentage time with intragastric pH >4 was significantly greater with rabeprazole vs. pantoprazole for the 24‐h postdose interval (44.0% vs. 32.8%; P < 0.001). Significant differences were observed in the daytime (51.0% vs. 42.2%; P < 0.001) and nighttime (32.0% vs. 16.9%; P < 0.001). Rabeprazole was also significantly superior in other intragastric pH parameters. There was no statistical difference for OAE between treatments. Conclusions In GERD patients with nocturnal heartburn, rabeprazole 20 mg was significantly more effective than pantoprazole 40 mg in percentage time with intragastric pH >4 during the nighttime, daytime, and 24‐h periods. Differences between treatments in OAE were not demonstrated. This trial is registered with http://clinicaltrials.gov , number NCT00237367.     

Acid inhibition on the first day of dosing: comparison of four proton pump inhibitors

BACKGROUND: Rapid and consistent acid suppression on the first day of dosing may be important in treating acid-related disorders. AIM: To compare the antisecretory activity and onset of action of single doses of rabeprazole, lansoprazole, pantoprazole, omeprazole capsule, omeprazole multiple unit pellet system (MUPS) tablet and placebo in healthy Helicobacter pylori-negative subjects. METHODS: This cross-over, double-blind, randomized study was performed in 18 H. pylori-negative subjects. Twenty-four-hour intragastric pH monitoring was performed on the day of treatment (once-daily dose of rabeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, omeprazole capsule 20 mg, omeprazole MUPS tablet 20 mg or placebo). RESULTS: The intragastric pH (3.4) and time at pH > 4 during the 24 h post-dose (8.0 h) were significantly greater with rabeprazole than with lansoprazole, pantoprazole, omeprazole capsule, omeprazole MUPS tablet or placebo (P 相似文献   

Gastric acidity and acid breakthrough with twice-daily omeprazole or lansoprazole

BACKGROUND: In patients with severe gastro-oesophageal reflux disease (GERD), proton pump inhibitors are being used increasingly in twice-daily regimens to improve control of gastric acidity. Few data exist to compare the ability of the most-often used proton pump inhibitors, omeprazole and lansoprazole, to control gastric acid at twice-daily dosage regimens. Nocturnal acid breakthrough, defined as gastric pH < 4.0 continuously for > 60 min, may compromise treatment goals in patients with GERD. AIM: To compare the effects of omeprazole 20 mg b.d. or lansoprazole 30 mg b.d. on gastric acidity and the relative ability of each dosage regimen to prevent acid breakthrough. METHODS: In a crossover pharmacodynamic study, 20 healthy volunteers (10 male, 10 female, mean age 38 years) were given omeprazole 20 mg b.d. or lansoprazole 30 mg b.d. for 7 days each, in a randomized manner. Each dosage regimen was separated by a minimum 7-day period where no medication was administered. On day 7 of each regimen, 24-h intragastric pH-metry was performed. The percentage of time for which gastric pH was below 4.0 and 3.0, the occurrence of daytime and nocturnal acid breakthrough, and the duration of action of each regimen were compared. Non-parametric statistics for paired data were used. RESULTS: The percentage time for which gastric pH was below 4.0 was significantly lower with omeprazole 20 mg b.d. (median 14.8%) than with lansoprazole 30 mg b. d. (median 24.2; P=0.0372). Fourteen subjects showed more effective acid control when taking omeprazole; these were significantly more often H. pylori-negative patients compared with those for whom acid control was better on lansoprazole (P < 0.001). Nocturnal acid breakthrough occurred in seven patients (35%) on omeprazole and in 10 (50%) on lansoprazole (N.S.). CONCLUSION: In healthy volunteers, twice-daily dosing of omeprazole 20 mg b.d. appears to be significantly more effective than lansoprazole 30 mg b.d. in controlling gastric acidity. The clinical importance of such a difference remains to be defined in GERD patients.     

Comparison of lansoprazole with omeprazole on 24-hour pH, acid secretion and serum gastrin in healthy volunteers

Background: Lansoprazole and omeprazole are proton pump inhibitors which both strongly inhibit acid secretion, resulting in a significant increase in serum gastrin levels. However, no direct comparison of recommended doses (20 mg for omeprazole and 30 mg for lansoprazole) has been reported so far. Our aims were to compare the effects of omeprazole 20 mg/day and lansoprazole 30 mg/day on intragastric acidity and serum gastrin concentration in 12 healthy volunteers. Methods: The study was double-blind, randomized and placebo-controlled with a cross-over design. On the seventh day of each period, 24-hour intragastric pH was measured using a combined glass electrode placed in the proximal stomach. The last morning dose of each regimen was taken at the end of 24-hour pH monitoring; acid output and serum gastrin concentrations were then studied in the fasting state and after stimulation with pentagastrin (maximal acid output) and a meal (post-prandial gastrin response). Results: Compared to placebo, both drug regimens induced a sustained increase of 24-hour intragastric pH and significantly decreased basal and pentagastrin-stimulated acid secretion. Lansoprazole 30 mg was slightly more effective than omeprazole 20 mg in terms of time spent above pH 3 (P < 0.05). Accordingly post-prandial gastrin concentrations rose slightly more after lansoprazole than after omeprazole. All other differences were insignificant. Conclusions: Both lansoprazole 30 mg and omeprazole 20 mg induce potent and long-lasting acid inhibition, with few minor differences when the two proton pump inhibitors are used at standard doses.     

Effect of Wy-45,727 on 24 h intragastric acidity in twenty normal volunteers.

1. The effects of single daily doses of 20, 50 and 150 mg of WY-45,727, a novel H2-receptor antagonist, and placebo were compared using long term pH-monitoring in 20 male volunteers. 2. Intragastric acidity was measured using combined Ingold glass electrodes. Subjects underwent four studies each under identical dietary conditions. Medication was taken after the evening meal. 3. Median 24 h pH rose from 1.3 (1.2-1.4 interquartile range) on placebo to 1.9 (1.6-2.8) on 20 mg WY-45,727, to 3.1 (2.3-3.7) on 50 mg WY-45,727 and to 4.5 (3.7-4.7) on 150 mg WY-45,727. All three doses increased 24 h and night-time pH significantly compared with placebo (P less than 0.0001). 4. The PAGE test for order effects confirmed clear dose dependent inhibition of acidity (P less than 0.0001). 5. Highly consistent individual responses were found during the night following 150 mg WY-45,727.