Evaluation of bioequivalence between a single-capsule formulation of esomeprazole 40 mg and acetylsalicylic acid 325 mg and the monotherapies given separately in healthy volunteers.

OBJECTIVE: The aim of this study was to investigate the bioequivalence of a single oral dose of esomeprazole 40 mg and acetylsalicylic acid 325 mg when formulated as a single capsule, relative to the components given as separate monotherapies. METHODS: This was an open, randomized, single-center, single-dose, 2-stage group sequential design, 2-way crossover study (NCT00688428) in 49 healthy adult volunteers (29 women). In each treatment period, subjects received a single dose of esomeprazole 40 mg and ASA 325 mg formulated as a single capsule or as separate monotherapies given in combination. Treatment periods were separated by a washout period of at least 6 days. The bioequivalence of a single-capsule formulation of esomeprazole 40 mg and ASA 325 mg relative to the monotherapies given individually was assessed by the geometric mean ratios of the area under the plasma concentration-time curve (AUC) and observed maximum plasma concentration (Cmax). If the 94% confidence interval (CI) of the geometric mean ratios of AUC and Cmax were within 0.80 - 1.25, bioequivalence would be established. A 94% CI was used to compensate for the multiple analyses of the study design, and to assure that the actual overall confidence level was 90%. RESULTS: The geometric mean ratios of the AUC for esomeprazole 40 mg and ASA 325 mg when administered in the single capsule formulation, relative to the monotherapies were 0.97 (94% CI, 0.90 - 1.04) and 1.04 (94% CI, 1.00 - 1.08). The corresponding mean geometric ratios for Cmax were 0.99 (94% CI, 0.90 - 1.09) and 1.02 (94% CI, 0.92 - 1.13). CONCLUSIONS: Treatment with esomeprazole 40 mg and ASA 325 mg formulated as a single capsule is bioequivalent to the separate monotherapies of esomeprazole 40 mg and ASA 325 mg when given in combination as separately-administered drugs in healthy adult subjects.

Evaluation of the pharmacokinetic interaction between esomeprazole (40 mg) and acetylsalicylic acid (325 mg) in healthy volunteers.

OBJECTIVE: To evaluate the effect of esomeprazole on the pharmacokinetics of low-dose acetylsalicylic acid (ASA) during repeated co-administration. METHODS: This was an open, randomized, 3-way crossover study in 55 healthy volunteers. Treatment periods comprised 5 days' oral esomeprazole (40 mg) or ASA (325 mg) alone, or in combination, separated by washout of >or= 13 days. The primary pharmacokinetic end points were steady-state area under the concentration-time curve (AUCtau) and observed maximum plasma concentration (Cmax) of ASA +/- esomeprazole. RESULTS: The estimates (90% confidence interval) of the geometric mean ratios for AUCtau and Cmax of ASA +/- esomeprazole were 1.04 (1.00 - 1.09) and 1.12 (1.03 - 1.22), respectively. Corresponding results for esomeprazole +/- ASA were 0.93 (0.89 - 0.98) and 0.96 (0.91 - 1.01), respectively. Administration of esomeprazole and ASA in combination was well tolerated. CONCLUSIONS: There was no pharmacokinetic interaction between esomeprazole (40 mg) and ASA (325 mg) during repeated co-administration in healthy volunteers.

Efficacy of esomeprazole for resolution of symptoms of heartburn and acid regurgitation in continuous users of non-steroidal anti-inflammatory drugs.

BACKGROUND: The use of non-steroidal anti-inflammatory drugs (NSAIDs) is often associated with upper gastrointestinal symptoms such as heartburn and acid regurgitation. AIM: To assess the efficacy of esomeprazole 20 and 40 mg for resolution of heartburn and acid regurgitation in continuous NSAIDs. METHODS: A post hoc analysis of five clinical trials was performed. Two identically designed, placebo-controlled, 4-week studies (NASA1, SPACE1) enrolled non-ulcer, NSAIDs-treated patients with upper abdominal pain, discomfort or burning. PLUTO and VENUS were identically designed, placebo-controlled, 6-month studies that enrolled patients at risk of NSAIDs-induced ulcers. Study 285 was an 8-week comparative study with ranitidine (300 mg/day) in patients with NSAIDs-induced gastric ulcers. Resolution of investigator-assessed heartburn and acid regurgitation was defined as symptom severity of 'none' in the last 7 days. RESULTS: In NASA1/SPACE1, heartburn resolved in 61% and 62% of patients taking esomeprazole 20 and 40 mg, respectively (vs. 36% on placebo, P < 0.001), and acid regurgitation resolved in 65% and 67% (vs. 48%, P < 0.001). Resolution of both symptoms was greater with esomeprazole than with placebo in PLUTO/VENUS (P

Prevalence and incidence of gastroduodenal ulcers during treatment with vascular protective doses of aspirin.

BACKGROUND: Aspirin is valuable for preventing vascular events, but information about ulcer frequency is necessary to inform risk-benefit decisions in individual patients. AIM: To determine ulcer prevalence and incidence in a population representative of those given aspirin therapy and evaluate risk predictors. METHODS: Patients taking aspirin 75-325 mg daily were recruited from four countries. Exclusions included use of gastroprotectant drugs or other non-steroidal anti-inflammatory drugs. We measured point prevalence of endoscopic ulcers, after quantitating dyspeptic symptoms. Incidence was assessed 3 months later in those eligible to continue (no baseline ulcer or reason for gastroprotectants). RESULTS: In 187 patients, ulcer prevalence was 11% [95% confidence interval (CI) 6.3-15.1%]. Only 20% had dyspeptic symptoms, not significantly different from patients without ulcer. Ulcer incidence in 113 patients followed for 3 months was 7% (95% CI 2.4-11.8%). Helicobacter pylori infection increased the risk of a duodenal ulcer [odds ratio (OR) 18.5, 95% CI 2.3-149.4], as did age >70 for ulcers in stomach and duodenum combined (OR 3.3, 95% CI 1.3-8.7). CONCLUSIONS: Gastroduodenal ulcers are found in one in 10 patients taking low-dose aspirin, and most are asymptomatic; this needs considering when discussing risks/benefits with patients. Risk factors include older age and H. pylori (for duodenal ulcer).

Lack of Pharmacokinetic Interaction between Esomeprazole and the Nonsteroidal Anti-Inflammatory Drugs Naproxen and Rofecoxib in Healthy Subjects.

BACKGROUND: We investigated the potential interactions between esomeprazole and a non-selective nonsteroidal anti-inflammatory drug (NSAID; naproxen) or a cyclo-oxygenase (COX)-2-selective NSAID (rofecoxib) in healthy subjects. METHODS: Two studies of identical randomised, open, three-way crossover design were conducted. Subjects (n = 32 for both studies) were to receive 1 week's treatment with esomeprazole 40mg once daily (studies A and B), naproxen 250mg twice daily (study A), rofecoxib 12.5mg once daily (study B), and esomeprazole in combination with naproxen (study A) or rofecoxib (study B). Study periods were separated by a 2-week washout period. RESULTS: On day 7 of dosing, the ratios (and 95% CIs) for the area under the plasma concentration-time curve during the dosing interval (AUC(tau)) and observed maximum plasma concentration (C(max)) of esomeprazole and NSAID combination/NSAID alone were 0.98 (0.94, 1.01) and 1.00 (0.97, 1.04), respectively, for study A, and 1.15 (1.06, 1.24) and 1.14 (1.02, 1.28), respectively, for study B. The ratios (and 95% CIs) for AUC(tau) and C(max) of esomeprazole and NSAID combination/esomeprazole alone were 0.96 (0.89, 1.03) and 0.92 (0.85, 1.00), respectively, for study A, and 1.05 (0.96, 1.15) and 1.05 (0.94, 1.18), respectively, for study B. All treatments were well tolerated during the study period. CONCLUSION: Naproxen and rofecoxib do not interact with esomeprazole, and esomeprazole does not affect the pharmacokinetics of naproxen or rofecoxib. These findings indicate that esomeprazole can be used in combination with NSAIDs without the risk of a pharmacokinetic interaction.

Pharmacokinetics of [14C]omeprazole in patients with impaired renal function.

Pharmacokinetics of [14C]omeprazole and its metabolites were studied after single intravenous and oral doses of 20 and 40 mg, respectively, to 12 patients with chronic renal insufficiency. Blood samples for determination of total radioactivity, omeprazole, OH-omeprazole, sulfone, and sulfide were taken for 24 hours. Urine was collected over 96 hours for determination of total radioactivity and during the first 24 hours for additional assay of omeprazole and metabolites. The mean systemic availability was 70%. The mean plasma t1/2 of omeprazole was 0.6 hours. Unchanged omeprazole was not measurable in urine. Derived pharmacokinetic constants of intact omeprazole were within the range of those reported in healthy individuals. The accumulated 24-hour excretion of radioactive metabolites was related significantly to creatinine clearance. The cumulative excretion of total radioactivity in urine over 96 hours in percent of given dose varied between 25% and 83%.

Intravenous omeprazole: effect of a loading dose on 24-h intragastric pH.

To determine the effect of three times daily dosing with intravenous omeprazole on intragastric acidity, 24 h intragastric pH was measured continuously with a monocrystalline antimony electrode system in II patients with inactive duodenal ulceration during fasting conditions. After a baseline investigation, two different dosage regimens of intravenous omeprazole were compared in a double-blind crossover study, with regard to their ability to keep the pH greater than or equal to 4 for as long as possible. Success in the individual patient was defined as pH greater than or equal to 4 for at least 90% over the 24-h period. Two doses of omeprazole [40 mg t.d.s. (120 mg) and 80 mg + 40 mg + 40 mg (160 mg)] were compared. Omeprazole (120 mg) increased the median of individual median intragastric 24-h pH from 1.49 to 6.67. The pH was greater than or equal to 4 for greater than or equal to 90% of the 24 h in three of the 11 patients. With omeprazole, 160 mg (a loading dose of 80 mg), the median of individual median intragastric 24-h pH increased to 7.33. The pH was greater than or equal to 4 for greater than or equal to 90% of the 24 h in seven of the 11 patients. Median time to reach pH 4 was 39 min after 40 mg and 20 min after 80 mg omeprazole. An initial loading dose of 80 mg omeprazole seems preferable to 40 mg to achieve a fast and sustained increase in intragastric pH to above 4 in the fasting patient.

Randomized, double-blind, placebo-controlled trial of prednisolone in post-infectious irritable bowel syndrome.

BACKGROUND: Post-infectious irritable bowel syndrome is associated with increased serotonin-containing enterochromaffin cells and lymphocytes in rectal biopsies. Animal studies have suggested that steroids reduce the lymphocyte response and suppress some of the post-infectious changes in neuromuscular function. AIM: To evaluate whether steroids reduce the number of enterochromaffin cells and improve the symptoms of post-infectious irritable bowel syndrome. METHODS: Twenty-nine patients with post-infectious irritable bowel syndrome underwent a randomized, double-blind, placebo-controlled trial of 3 weeks of oral prednisolone, 30 mg/day. Mucosal enterochromaffin cells, T lymphocytes and mast cells were assessed in rectal biopsies before and after treatment, and bowel symptoms were recorded in a daily diary. RESULTS: Initial enterochromaffin cell counts were increased and correlated with initial lamina propria T-lymphocyte counts (r = 0.460, P = 0.014). Enterochromaffin cell counts did not change significantly after either prednisolone (- 0.8% +/- 9.2%) or placebo (7.9% +/- 7.9%) (P = 0.5). Although lamina propria T-lymphocyte counts decreased significantly after prednisolone (22.0% +/- 5.6%, P = 0.003), but not after placebo (11.5% +/- 8.6%, P = 0.1), this was not associated with any significant treatment-related improvement in abdominal pain, diarrhoea, frequency or urgency. CONCLUSIONS: Prednisolone does not appear to reduce the number of enterochromaffin cells or cause an improvement in symptoms in post-infectious irritable bowel syndrome. Other approaches to this persistent condition are indicated.

The Visceral Sensitivity Index: development and validation of a gastrointestinal symptom-specific anxiety scale.

BACKGROUND: Anxiety related to gastrointestinal sensations, symptoms or the contexts in which these may occur is thought to play a significant role in the pathophysiology as well as in the health outcomes of patients with irritable bowel syndrome. AIM: To develop a valid and reliable psychometric instrument that measures gastrointestinal symptom-specific anxiety. METHODS: External and internal expert panels as well as a patient focus group evaluated a large pool of potential item stems gathered from the psychological and gastrointestinal literature. Potential scale items were then administered to 96 patients diagnosed with irritable bowel syndrome along with a set of validating questionnaires. Final item selection was based upon rigorous empirical criteria and the psychometric properties of the final scale were examined. RESULTS: A final unidimensional 15-item scale, the Visceral Sensitivity Index, demonstrated excellent reliability as well as good content, convergent, divergent and predictive validity. CONCLUSIONS: The findings suggest that the Visceral Sensitivity Index is a reliable, valid measure of gastrointestinal symptom-specific anxiety that may be useful for clinical assessment, treatment outcome studies, and mechanistic studies of the role of symptom-related anxiety in patients with irritable bowel syndrome.

Characteristics of patients with irritable bowel syndrome recruited from three sources: implications for clinical trials.

BACKGROUND: Variation in the characteristics of irritable bowel syndrome patients recruited for clinical trials from different sources could affect their response and the generalizability of trial results. AIM: To describe and compare the characteristics of three different groups of irritable bowel syndrome patients recruited into a 'mock clinical trial.' METHODS: We enrolled 245 irritable bowel syndrome patients from three sources: (i) 121 from British primary practitioners; (ii) 72 from California newspaper advertisements; and (iii) 52 from a California gastroenterologist's practice. We obtained demographic, clinical, and Hospital Anxiety and Depression (HAD) Scale data. RESULTS: Most patients were young to middle-aged women; the majority reported symptoms for > 5 years in all three groups. Subject characteristics varied among the groups. Typically, primary care patients were anxious, smokers and daily alcohol drinkers who had sought care recently for irritable bowel syndrome and tried antispasmodic drugs. Their symptoms were intermediate in severity between those of the other two groups. Advertisement subjects were the oldest, most highly educated, most often depressed, and were least likely to have sought care recently for symptoms, which were almost uniformly only moderate in severity. Gastroenterologist patients tended to be anxious and had nearly all sought care recently for symptoms, which were the most severe and most likely to include all three pain-related Rome I criteria. CONCLUSION: Recruitment methodology affects important characteristics of an irritable bowel syndrome study group.

A double-blind placebo-controlled study of buspirone-stimulated prolactin release in non-ulcer dyspepsia--are central serotoninergic responses enhanced?

BACKGROUND: Dyspepsia is a common symptom for which an organic cause is found in only 40% of patients. When no cause is apparent and the dyspepsia is considered to be idiopathic, a diagnosis of non-ulcer dyspepsia is made. The pathophysiology of non-ulcer dyspepsia is poorly understood and numerous theories have been put forward, including a theory of enhanced central serotoninergic receptor sensitivity. AIM: To determine the sensitivity of serotonin receptors in non-ulcer dyspepsia. METHODS: Using a randomized, double-blind, placebo-controlled design, we compared buspirone (a serotonin type 1a partial agonist)-stimulated prolactin release in 50 patients and 59 healthy comparison subjects. Buspirone, 30 mg, or matching placebo was administered on two separate occasions and prolactin release over 180 min was monitored. Patients and healthy subjects received both treatments in random order, 1 week apart. RESULTS: Overall, patients with non-ulcer dyspepsia had greater prolactin release in response to the buspirone challenge than the healthy comparison subjects, with differences most significant at 90 min following the challenge. Enhancement occurred in patients both with and without Helicobacter pylori infection. Female subjects, both patients and healthy volunteers, showed a greater response to buspirone than male subjects, and the augmentation of response observed in male and female patients was greater in females. CONCLUSIONS: Patients with non-ulcer dyspepsia have enhanced central serotoninergic responses and such responses are independent of H. pylori infection. Blockade of such receptors might be an appropriate therapeutic strategy.

Impact of cortisol on buspirone stimulated prolactin release: a double-blind placebo-controlled study.

Buspirone is known to stimulate prolactin release. Clinical studies (e.g. in chronic fatigue syndrome) suggest that the response may be influenced by baseline cortisol levels. We conducted a double-blind placebo-controlled study to examine the relationship between the prolactin response to buspirone challenge and baseline cortisol level. Fifty healthy volunteers took part in the study. Buspirone was found to consistently elevate PRL levels above those seen following placebo administration. The PRL response as measured by area under the curve was highly correlated with the baseline cortisol level.

Gastro-duodenal protection in an era of cyclo-oxygenase-2-selective nonsteroidal anti-inflammatory drugs.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective and necessary for the relief of pain and inflammation in patients with arthritis. NSAIDs are however also associated with an increased risk for ulceration in the stomach and in the duodenum, and many NSAID users experience bothersome dyspeptic symptoms during continued NSAID therapy. PPIs like omeprazole, have been shown to heal and to prevent ulcers and dyspeptic symptoms during continued NSAID therapy, and during continued NSAID therapy the prostaglandin analogue, misoprostol, has been shown to reduce the risk for ulcer complications. The COX-2 selective NSAID, rofecoxib, is in comparison with naproxen, a non-selective NSAID, associated with fewer clinically important upper gastrointestinal events. The incidence of myocardial infarctions seems, however, to be lower with naproxen than with rofecoxib, and this is expected to lead to low-dose aspirin use in rofecoxib users at risk for cardiovascular events. Co-administration of the COX-2 selective NSAID, celecoxib, and low-dose aspirin, is associated with the same risk for upper gastrointestinal ulcer complications alone and combined with symptomatic ulcers, as the non-selective NSAIDs, ibuprofen and diclofenac. A proton pump inhibitor (PPI) should be used for healing of NSAID-associated ulcers, and a PPI or misoprostol should be considered for prevention of ulceration in non-selective NSAID users at risk for ulceration. The experience with COX-2 selective NSAIDs is still limited, and it remains to be studied whether subpopulations of COX-2 selective NSAID users will benefit from gastro-duodenal protection.

Omeprazole and H2-receptor antagonists in the acute treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis: a meta-analysis.

This paper is a meta-analysis of 30 published, double-blind clinical trials comparing omeprazole with ranitidine or cimetidine for the treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. These studies compare the recommended doses of omeprazole with those for ranitidine and cimetidine, and the confidence intervals for the therapeutic gain show that the findings are highly reliable. The difference in healing rates favoured omeprazole over ranitidine in patients with duodenal ulcer after 2 weeks of treatment (15.2 percentage units; P < 0.001), and after 4 weeks of treatment in patients with gastric ulcer (9.9 percentage units; P = 0.005), or reflux oesophagitis (23 percentage units; P < 0.001). Similarly, omeprazole gave a 20.6 percentage units higher average healing rate than cimetidine in patients with duodenal ulcer after 2 weeks of treatment (P < 0.0001). Significantly more patients treated with omeprazole were free of symptoms at their first follow-up visit than patients treated with ranitidine or cimetidine.

Predictors of gastroduodenal erosions in patients taking low-dose aspirin.

BACKGROUND: Gastroduodenal ulcers are common in patients taking low-dose aspirin. However, the factors predisposing to mucosal erosions, the precursor lesions, are not well known. AIMS: To examine the potential risk factors for the development of erosions in patients chronically taking low-dose aspirin. METHODS: Patients included were taking aspirin 75-325 mg daily for >28 days. Exclusion criteria included use of nonsteroidal anti-inflammatory and ulcer-healing drugs. Demographic data were collected at baseline, prior to endoscopy to determine the frequency and number of erosions and Helicobacter pylori status. In those without ulcer or other exclusions, endoscopy was repeated at 3 months. RESULTS: Fewer patients had gastric erosions if they were H. pylori +ve (48.5% vs. 66.4% in H. pylori-ve patients at baseline, P = 0.17; 40.0% vs. 64.1% at 3 months, P = 0.029). If gastric erosions were present, they were also less numerous in H. pylori +ve patients (3.61 +/- 0.83 vs. 4.90 +/- 0.53 at baseline, P = 0.026; 2.17 +/- 0.68 vs. 5.68 +/- 0.86 at 3 months, P = 0.029). There was a trend (0.1 > P > 0.05) for more gastric erosions in those taking >100 mg/day aspirin. Males had more duodenal erosions at baseline (25.2% vs. 7.5%, P = 0.016). Patient age did not affect the presence or number of erosions. H. Pylori was not significantly associated with duodenal erosion numbers. CONCLUSIONS: Helicobacter pylori infection may partially protect against low-dose aspirin-induced gastric erosions; damage to the stomach appears weakly dose-related; and older age does not increase the risk of erosions.

Systematic review: ulcer definition in NSAID ulcer prevention trials.

BACKGROUND: In clinical trials of peptic ulcer prevention, the most appropriate definition of an ulcer remains challenging. AIMS: To evaluate the ulcer definitions used in clinical trials of ulcer prevention among non-steroidal anti-inflammatory drug users and to determine whether any specific definition is preferred. METHODS: A systematic literature search of the PubMed, Medline and EMBASE databases was conducted. Results were limited to full papers published in English from June 1987 to June 2007 that met the following criteria: randomized, controlled non-steroidal anti-inflammatory drug trials of > or =8 weeks' duration, with a primary end point of ulcer upon endoscopy. RESULTS: Forty five publications met the inclusion criteria and were reviewed. Overall, an ulcer diameter of > or =3 mm was used in 25 publications and most included a description of ulcer depth. Of the remainder, ulcer was defined as any lesion with unequivocal/observable depth (with no lower limit for ulcer diameter; five publications) or an excavated mucosal break >3 mm (one publication), whereas nine defined a minimum ulcer size of > or =5 or >5 mm. Ulcer definition was unclear in the remaining five publications. CONCLUSION: In clinical trials of ulcer prevention among non-steroidal anti-inflammatory drug users, a gastric or duodenal lesion > or =3 mm in diameter with significant depth is the preferred definition.

Is ranitidine therapy sufficient for healing peptic ulcers associated with non-steroidal anti-inflammatory drug use?

Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) increases the risk of serious gastroduodenal events. To minimise these risks, patients often require concomitant acid-suppressive therapy. We conducted a literature review of clinical trials examining use of ranitidine 150 mg twice daily to heal gastroduodenal ulcers (GU) in NSAID recipients. Seven studies were identified. After 8 weeks' treatment with ranitidine, GU healing rates ranged from 50% to 74% and rates of duodenal ulcer (DU) healing ranged from 81% to 84%. Ranitidine was more effective when NSAIDs were discontinued (healing rates reaching 95% and 100%, respectively). The ulcer healing rate with sucralfate was similar to that of ranitidine. However, proton pump inhibitor (PPI) therapy was associated with significantly greater rates of both GU and DU healing than ranitidine; 8-week GU rates were 92% and 88% with esomeprazole 40 mg and 20 mg, respectively (vs. 74% with ranitidine, p < 0.01). For omeprazole, 8-week healing rates were 87% with omeprazole 40 mg and 84% with omeprazole 20 mg (vs. 64% for ranitidine, p < 0.001), and for lansoprazole the corresponding values were 73-74% and 66-69% for the 30 mg and 15 mg doses, respectively (vs. 50-53% for ranitidine, p < 0.05). In the PPI study reporting DU healing the values were 92% for omeprazole 20 mg (vs. 81% for ranitidine, p < 0.05) and 88% for omeprazole 40 mg (p = 0.17 vs. ranitidine). NSAID-associated GU are more likely to heal when patients receive concomitant treatment with a PPI rather than ranitidine.

Identical 24-hour gastric pH profiles when using intragastric antimony or glass electrodes or aspirated gastric juice.

Intragastric pH was continuously measured over 24 h with a monocrystalline antimony electrode system and was compared with pH measured in simultaneously aspirated gastric juice and with pH measured by using a conventional intragastric glass electrode. There was a marked correlation between the pH readings obtained with the monocrystalline antimony electrode and the pH values measured in aspirated gastric juice (r = 0.92, p less than 0.001) and with the pH readings obtained with the intragastric glass electrode (r = 0.92, p less than 0.001). Both readings of pH with glass electrode and of pH after aspiration can be predicted by readings of pH with antimony electrode by using linear regression lines with slopes close to 1. Intragastric pH measurement is an alternative to aspiration of gastric juice, and the result obtained with an electrode of monocrystalline antimony is comparable to that obtained with a conventional glass electrode.

Effect of omeprazole, a substituted benzimidazole, on 24-h intragastric acidity in patients with peptic ulcer disease.

Intragastric pH was measured during physiological conditions over 24-h periods in patients with peptic ulcer disease. After single oral doses of 20, 40, and 80 mg omeprazole we found a dose-dependent reduction in mean intragastric acidity ranging from 38% to 99%. After treatment for 1 week with omeprazole, 40 mg daily, with or without an initial loading dose of 80 mg, intragastric acidity was decreased by more than 99%. This is a more pronounced decrease in acidity than can be achieved even with very high doses of histamine H2-receptor antagonists.

The effect of 20 Mg omeprazole daily on serum gastrin, 24-h intragastric acidity, and bile acid concentration in duodenal ulcer patients.

Serum gastrin, 24-h intragastric acidity, and bile acid concentrations were measured during physiologic conditions in 10 patients with duodenal ulcer disease. Omeprazole, 20 mg daily, for 8 days reduced acidity by greater than or equal to 99% in six patients and by 47-54% in four patients. The degree of acid reduction was related to the area under the plasma omeprazole concentration time curve (AUC). Serum gastrin levels were not significantly increased by omeprazole. Intragastric bile acid concentrations were increased by omeprazole, but this seems to be of little importance for the healing of duodenal ulcers.