Pantoprazole therapy in the long-term management of severe acid peptic disease: clinical efficacy, safety, serum gastrin, gastric histology, and endocrine cell studies

A review on lactoferrin as a proton pump inhibitor

Lactoferrin (Lf) is a versatile natural milk-derived protein that exhibits multiple interesting biological activities. Since it is safe for human administration and currently manufactured using low cost and well-established large-scale processes, the Lf scientific community has been devoted at dissecting its mechanisms of action towards its more rational and efficient use for various applications. Emerging literature has identified proton pumping ATPases as molecular targets of Lf in different cellular models linked to distinct activities of this natural protein. Information on this subject has not been systematically analysed before, hence herein we review the current state of art on the effect of Lf on proton pumping ATPases. Though structurally different, we propose that Lf holds a proton pump inhibitor (PPI)-like activity based on the functional resemblance with the classical inhibitors of the stomach H⁺/K⁺-ATPase. The downstream events and outcomes of the PPI-like activity of Lf, as well as its impact for the development of improved Lf applications are also discussed.

Gastrin and the Moderate Hypergastrinemias

The antral hormone gastrin potently regulates gastric acid secretion and fundic mucosal growth. Consequently, appropriate gastrin secretion and plasma concentrations are important for the early phases of digestion. This review describes as the first premise the normal biogenesis of gastrin in the antral mucosa, but also mentions the extraantral expression. Subsequently, the molecular nature and concentration levels of gastrin in serum or plasma are overviewed. Third, assays for accurate measurements of plasma or serum concentrations are commented. Finally, the problem of moderate hypergastrinemia due to Helicobacter pylori infections and/or treatment with proton-pump inhibitors (PPI) is discussed. The review concludes that accurate measurement of the true concentrations of bioactive gastrins in plasma is important. Moreover, it suggests that moderate hypergastrinemias are also essential health issues that require serious attention.

Effects of dexlansoprazole MR, a novel dual delayed release formulation of a proton pump inhibitor, on plasma gastrin levels in healthy subjects

Dexlansoprazole MR is a modified release formulation of a proton pump inhibitor being developed for the treatment of acid-related disorders. The purpose of this study is to characterize the plasma gastrin (PG) profile associated with administration of dexlansoprazole MR. Forty-two healthy subjects receive dexlansoprazole MR 90 mg, dexlansoprazole MR 120 mg, and lansoprazole 30 mg once daily for 5 days in a randomized, open-label, 3-period crossover study with at least 14-day washout intervals. Twenty-four-hour PG profiles are obtained at baseline (day -1 of period 1) and on days 1 and 5 in each period. Fasting PG levels are determined on days 8 and 12 in periods 1 and 2. On day 1, 24-hour PG levels increase from baseline to a similar extent with all regimens. On day 5, 24-hour PG levels with both dexlansoprazole MR regimens increase further and to a similar extent and are slightly higher than PG levels with lansoprazole. For all regimens, fasting PG levels on days 5 and 6 are higher than baseline levels (P<.05) and start to decrease by day 8, returning to near baseline at day 12. In this study, dexlansoprazole MR administration results in moderate increases in PG, similar to lansoprazole, which return to baseline levels within 7 days post dosing.

Diagnosis and differential diagnosis of hypergastrinemia

The most frequent conditions of hypergastrinemia in man are the Zollinger-Ellison syndrome with autonomous gastrin hypersecretion by the tumour cell and reactive hypergastrinemia in type A autoimmune chronic atrophic gastritis with achlorhydria causing unrestrained gastrin release from the gastrin-producing antral G-cells. Both entities differ with respect to the pH in the gastric fluid, which is < 2 in patients with Zollinger-Ellison syndrome and neutral in type A gastritis. Other conditions with moderate hypergastrinemia as treatment with proton pump inhibitors, gastric outlet obstruction, previous vagotomy, chronic renal failure or short bowel syndrome are of minor clinical importance.

Pantoprazole: a proton pump inhibitor with oral and intravenous formulations

Proton pump inhibitors (PPI) are a significant part of therapy for most acid-related diseases including gastroesophageal reflux disease, peptic ulcer disease and acute gastrointestinal bleeding. Pantoprazole is one of several available proton pump inhibitor agents and provides dose-dependent control of gastric acid secretion. Pantoprazole has indications in gastroesophageal reflux disease and peptic ulcer disease, along with indications as co-therapy in the eradication of Helicobacter pylori infection and in the control of the acid secretion associated with the Zollinger-Ellison syndrome, as well as in NSAID ulcer prevention. Pantoprazole is available in both oral and intravenous formulations. It is effective across all age groups, although only indicated in adults (and adolescents in Europe). It has been approved for use in over 100 countries and has been used for over 13 years. Pantoprazole has an excellent safety profile and a low potential for drug-drug interactions. While still widely prescribed, pantoprazole and the other branded proton pump inhibitors are under considerable market pressure from the less expensive but similarly effective generic and over-the-counter formulations of omeprazole.

Long-term use of proton pump inhibitors does not affect the frequency, growth, or histologic characteristics of colon adenomas

BACKGROUND

The clinical significance of the trophic effects of long-term proton pump inhibitors (PPI)-related hypergastrinemia on colon polyps remains unknown.

AIM

To study the frequency, growth, and histology of colon polyps in patients on chronic PPI therapy (cases), compared to those not receiving acid suppression (controls).

METHODS

Medical records of 2868 consecutive patients who underwent two or more colonoscopies, performed 3 or more months apart were reviewed. Cases (116) that used PPIs between the two colonoscopies were then compared to controls (194).

RESULTS

Demographics and risk factors for colon cancer were comparable between the two groups. At baseline the mean frequency and size of adenomatous polyps were similar in cases and controls (P > 0.05) and at follow-up, these were 0.89 and 1.18 (P > 0.05; 95% CI of -0.08 to 0.66) and 4.09 mm and 4.00 mm (P > 0.05; 95% CI -2.29 to 2.11), respectively with no significant change. However, control group had a higher mean frequency and size of hyperplastic polyps at baseline as well as at follow-up colonoscopy (P < 0.05).

CONCLUSIONS

The long-term use of PPI does not influence the frequency, growth, or histology of adenomatous polyps, but is associated with a reduction in both baseline and interval development of hyperplastic polyps.

Long-term management of gastroesophageal reflux disease with pantoprazole

Gastroesophageal reflux disease (GERD) is a chronic, relapsing disease that can progress to major complications. Affected patients have poorer health-related quality of life than the general population. As GERD requires continued therapy to prevent relapse and complications, most patients with erosive esophagitis require long-term acid suppressive treatment. Thus GERD results in a significant cost burden and poor health-related quality of life. The effective treatment of GERD provides symptom resolution and high rates of remission in erosive esophagitis, lowers the incidence of GERD complications, improves health-related quality of life, and reduces the cost of this disease. Proton pump inhibitors are accepted as the most effective initial and maintenance treatment for GERD. Oral pantoprazole is a safe, well tolerated and effective initial and maintenance treatment for patients with nonerosive GERD or erosive esophagitis. Oral pantoprazole has greater efficacy than histamine H(2)-receptor antagonists and generally similar efficacy to other proton pump inhibitors for the initial and maintenance treatment of GERD. In addition, oral pantoprazole has been shown to improve the quality of life of patients with GERD and is associated with high levels of patient satisfaction with therapy. GERD appears to be more common and more severe in the elderly, and pantoprazole has shown to be an effective treatment for this at-risk population.

Does long-term medication with a proton pump inhibitor induce a tolerance to H2 receptor antagonist?

BACKGROUND

Previous reports suggest that complete tolerance to H2 receptor antagonists (H2RAs) in patients with regular H2RA medication may be due to hypergastrinemia-increased histamine synthesis or upregulation of H2 receptors. As proton pump inhibitors (PPIs) have been reported to induce hypergastrinemia (similar to H2RAs), patients receiving long-term medication with PPIs may show tolerance to preanesthetic H2RA. Therefore, we studied the efficacy of an H2RA, roxatidine, in patients receiving long-term PPI medication.

METHODS

Effects of H2RA in 15 surgical patients receiving a regular PPI for more than 4 weeks (PPI+H2RA group) were compared with those in 30 patients not receiving regular PPIs or H2RAs (None+H2RA group and None+None group, n = 15 each). Oral roxatidine was given to both PPI+H2RA and None+H2RA group patients as an anesthetic premedication, while it was not given to None+None group patients. Gastric volume and pH were measured after induction of anesthesia.

RESULTS

Gastric pH and volume (ml) in the PPI+H2RA group (5.79 +/- 1.61 and 9.1 +/- 16.7, respectively) were both similar to those in the None+H2RA group (5.54 +/- 2.20 and 9.7 +/- 10.8, respectively) but were significantly higher (gastric pH) and lower (volume) than in the None+None group (2.29 +/- 1.84 and 29.3 +/- 22.8, respectively, P < 0.01).

CONCLUSIONS

These data suggest that long-term PPI medication may not induce a tolerance to H2RAs.

Recent advances in the treatment of GERD in the elderly: focus on proton pump inhibitors

The prevalence of gastroesophageal reflux disease (GERD) increases with age, and older people are more likely to develop severe disease. Studies of elderly patients with GERD indicate differences in presentation and diagnosis, compared with GERD in younger adults. Indeed, an older patient with GERD may present with atypical symptoms such as dysphagia, vomiting, weight loss, anaemia and anorexia, and less frequently with typical symptoms such as heartburn or acid regurgitation. These findings are attributed to pathophysiological changes in esophageal function that occur with age. Therefore, GERD in elderly patients is more likely to be poorly diagnosed or undiagnosed. Although few studies have concentrated specifically on elderly patients, the proton pump inhibitors (PPIs) have been shown to be more effective than histamine receptor antagonists for healing reflux esophagitis and for preventing its recurrence when they are given as maintenance therapy. In addition, the PPIs seem to be safe both in short- and in long-term therapy of elderly patients with GERD.

Effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa

BACKGROUND

Prolonged gastric acid suppression leads to hypergastrinaemia, which promotes hyperplasia of the enterochromaffin-like (ECL) cells of the oxyntic mucosa. The objective was to determine the effects of 5 years of treatment with rabeprazole or omeprazole on the gastric mucosa.

METHODS

Two hundred and forty-three patients received rabeprazole (20 mg or 10 mg) or omeprazole (20 mg) once daily for up to 5 years, for gastro-oesophageal reflux disease and 51% completed the whole 5 year period. Gastric biopsy specimens were taken and examined for gastritis, Helicobacter pylori infection, and ECL cell status.

FINDINGS

H. pylori infection in the gastric corpus was more common than in the antrum, and remained constant, whereas antral H. pylori infection became less common as the study progressed. H. pylori infection was a highly significant predictor of higher gastritis scores, which were similar among the three treatment groups. ECL cell hyperplasia occurred in a minority of patients, and was associated with serum gastrin concentrations. No ECL cell dysplasia or tumours were observed. There were no significant differences among the treatment groups in gastritis or ECL cell hyperplasia grades.

INTERPRETATION

This study has confirmed the link between ECL cell hyperplasia and elevated serum gastrin concentrations, but has found no evidence that this progresses to high grades of hyperplasia during 5 years of treatment with rabeprazole or omeprazole.

Pantoprazole in severe acid-peptic disease: the effectiveness and safety of 5 years' continuous treatment

OBJECTIVE

This is our final report on the clinical effectiveness and safety of long-term pantoprazole in patients with severe peptic ulcer or reflux disease during continuous treatment for up to 5 years.

METHODS

Patients (n= 150) with peptic ulcer or reflux erosive oesophagitis running an aggressive course or with complications, and refractory to H2-receptor antagonists, were entered into this 5-year programme. Assessment was by serial endoscopy, clinical examination, serum gastrin estimation, gastric mucosal histology and mucosal endocrine cell quantification.

RESULTS

Healing results were presented earlier. The estimated rates of remission on maintenance treatment with pantoprazole (n = 115) were 82% at 1 year, 75% at 2 years, 72% at 3 years, 70% at 4 years and 68% at 5 years. Helicobacter pylori infection appeared not to influence the outcome in reflux patients, with roughly two-thirds continuing in remission irrespective of infection. Only four patients had adverse events considered to be definitely related to pantoprazole. Median gastrin levels rose by 1.5-2-fold and were higher in those with H. pylori infection; 13 patients had levels >500 ng/L on at least one occasion, but these high levels were not sustained. Histological changes were more marked in patients infected with H. pylori: chronic gastritis decreased in the antrum and increased in the corpus, which also showed atrophic changes. The total number of endocrine cells in the antrum showed little variation over 60 months but fell by around one-third in the corpus.

CONCLUSION

Long-term treatment with pantoprazole is effective and safe.

Short- and long-term therapy for reflux oesophagitis in the elderly: a multi-centre, placebo-controlled study with pantoprazole

BACKGROUND

No placebo-controlled clinical trials have yet been published on the efficacy of therapy in older subjects with oesophagitis.

AIM

To evaluate the efficacy of pantoprazole in preventing the recurrence of oesophagitis in elderly subjects.

METHODS

One hundred and sixty-four patients aged 65 years and over with acute oesophagitis were treated openly with pantoprazole, 40 mg daily, for 8 weeks. Patients with documented healing of erosive oesophagitis were then treated with pantoprazole, 20 mg daily, for 6 months. Thereafter, cured patients were randomized to receive pantoprazole, 20 mg daily, or placebo for the following 6 months. Clinical evaluations were performed every 2 months, and endoscopy was repeated after 8 weeks and after 6 and 12 months and/or whenever symptoms suggested a relapse of oesophagitis.

RESULTS

After 8 weeks, the healing rates of oesophagitis were 81.1% (75.1-87.1%) and 93.7% (89.7-97.7%) by intention-to-treat and per protocol analyses, respectively. After 6 months, the corresponding values were 82% (75.4-88.5%) and 92.4% (87.6-97.2%), respectively. After 12 months, the per protocol and intention-to-treat healing rates of oesophagitis were 95.1% (88.5-100%) and 79.6% (68.3-90.9%), respectively, in the treatment group vs. 32.7% (19.9-45.4%) and 30.4% (18.3-42.4%), respectively, in the placebo group (P = 0.0001). Heartburn, acid regurgitation and chest pain were significantly associated with the relapse of oesophagitis (P = 0.0001), whereas hiatus hernia, Helicobacter pylori infection, concomitant diseases and treatments were not.

CONCLUSION

In the elderly, pantoprazole was highly effective in healing and reducing the relapse of oesophagitis; discontinuing active treatment after 6 months was associated with a significant increase in the relapse rate.

Meta-analysis: comparing the efficacy of proton pump inhibitors in short-term use

BACKGROUND

Proton pump inhibitors have a prominent role in the management of acid-related diseases. Controlling expenses on proton pump inhibitors would yield great economic benefits for Dutch health care.

AIM

To investigate whether clinical differences in proton pump inhibitors exist.

METHODS

We searched Medline, EMBASE and the Cochrane Library. We identified papers in English, German, French or Dutch in which two or more proton pump inhibitors were compared under the same clinical conditions in gastro-oesophageal reflux disease, peptic ulcer disease or Helicobacter pylori eradication. The pooled relative risks were calculated using the Mantel-Haenszel method.

RESULTS

Two significant differences were found in the proton pump inhibitors compared. In gastro-oesophageal reflux disease, esomeprazole 40 mg was superior to omeprazole 20 mg (relative risk, 1.18; 95% confidence interval, 1.14-1.23). In peptic ulcer disease, pantoprazole 40 mg was superior to omeprazole 20 mg (relative risk, 1.07; 95% confidence interval, 1.02-1.13). In Helicobacter pylori eradication, no significant differences were found.

CONCLUSIONS

Both significant differences found were in favour of the highest dose of proton pump inhibitor on a milligram basis. This indicates that the difference may be dose dependent and not proton pump inhibitor specific. Therefore, when prescribing proton pump inhibitors, arguments other than clinical efficacy, such as those related to pharmaco-economics, may be considered.

A randomized, double-blind trial of the efficacy and safety of 10 or 20 mg rabeprazole compared with 20 mg omeprazole in the maintenance of gastro-oesophageal reflux disease over 5 years

BACKGROUND

Gastro-oesophageal reflux disease has a chronic course, and often requires long-term treatment. Proton pump inhibitors are the treatment of choice for both acute and maintenance treatment, but little is known from randomized controlled trials of their effects beyond 1 year.

AIM

To compare the efficacy and safety of two doses of rabeprazole with 20 mg omeprazole in the maintenance treatment of erosive gastro-oesophageal reflux disease over 5 years.

METHODS

Two hundred and forty-three patients who had previously responded to acute treatment for erosive gastro-oesophageal reflux disease were prospectively randomized to receive 5 years of treatment with rabeprazole (10 or 20 mg daily) or omeprazole (20 mg daily). The primary outcome measure was endoscopically confirmed relapse of erosive gastro-oesophageal reflux disease.

RESULTS

One hundred and twenty-three patients (51%) completed all 5 years of the study, with similar completion rates in the three groups. Relapses occurred in nine of 78 (11.5%), eight of 82 (9.8%) and 11 of 83 (13.3%) patients in the rabeprazole 20 mg, rabeprazole 10 mg and omeprazole 20 mg groups, respectively. Gastric biopsy showed no evidence of any harmful effects. All treatments were well tolerated.

CONCLUSIONS

Rabeprazole 10 mg, rabeprazole 20 mg and omeprazole 20 mg all had similar efficacy in the maintenance treatment of gastro-oesophageal reflux disease. All three were safe and well tolerated during 5 years of treatment.