Three-year oral pantoprazole administration is effective for patients with Zollinger-Ellison syndrome and other hypersecretory conditions

Gastrinoma With Relatively Low Gastrin Levels: A Case Report

Gastrinomas can often be cured with surgical removal if detected early enough. We present a case report where a patient was diagnosed with gastrinoma with relatively low serum gastrin levels after subsequent duodenojejunostomy, gastrojejunostomy, total gastrectomy, and cholecystectomy. With this case report, we hope to promote a higher level of awareness of pancreatic neuroendocrine (NE) tumors and educate clinicians on the full effects of proton pump inhibitor (PPI) use on patient workup, diagnostics, and care.

Successful Lifetime/Long-Term Medical Treatment of Acid Hypersecretion in Zollinger-Ellison Syndrome (ZES): Myth or Fact? Insights from an Analysis of Results of NIH Long-Term Prospective Studies of ZES

Analysis of the efficacy/pharmacology of long-term/lifetime medical treatment of acid hypersecretion in a large cohort of ZES patients in a prospective study. This study includes the results from all 303 patients with established ZES who were prospectively followed and received acid antisecretory treatment with either H2Rs or PPIs, with antisecretory doses individually titrated by the results of regular gastric acid testing. The study includes patients treated for short-term periods (<5 yrs), patients treated long-term (>5 yrs), and patients with lifetime treatment (30%) followed for up to 48 years (mean 14 yrs). Long-term/lifelong acid antisecretory treatment with H2Rs/PPIs can be successfully carried out in all patients with both uncomplicated and complicated ZES (i.e., with MEN1/ZES, previous Billroth 2, severe GERD). This is only possible if drug doses are individually set by assessing acid secretory control to establish proven criteria, with regular reassessments and readjustments. Frequent dose changes both upward and downward are needed, as well as regulation of the dosing frequency, and there is a primary reliance on the use of PPIs. Prognostic factors predicting patients with PPI dose changes are identified, which need to be studied prospectively to develop a useful predictive algorithm that could be clinically useful for tailored long-term/lifetime therapy in these patients.

Radiological Features of Zollinger–Ellison Syndrome: A Report of Two Cases

Hypersecretion of gastrin from duodenal or pancreatic gastrinomas results in a rare clinical entity called Zollinger–Ellison syndrome (ZES). It mostly presents with abdominal pain and diarrhea. ZES may be sporadic or occur in association with multiple endocrine neoplasia type 1. Usually, ZES manifests between 20 and 50 years.

We report two cases of patients who presented with abdominal pain, vomiting, watery diarrhea, and significant weight loss.

AGA Clinical Practice Update on De-Prescribing of Proton Pump Inhibitors: Expert Review

DESCRIPTION

Proton pump inhibitors (PPIs) are among the most commonly used medications in the world. Developed for the treatment and prevention of acid-mediated upper gastrointestinal conditions, these agents are being used increasingly for indications where their benefits are less certain. PPI overprescription imposes an economic cost and contributes to polypharmacy. In addition, PPI use has been increasingly linked to a number of adverse events (PPI-associated adverse events [PAAEs]). Therefore, de-prescribing of PPIs is an important strategy to lower pill burden while reducing real costs and theoretical risks. The purpose of this clinical update was to provide Best Practice Advice (BPA) statements about how to approach PPI de-prescribing in ambulatory patients.

METHODS

Our guiding principle was that, although PPIs are generally safe, patients should not use any medication when there is not a reasonable expectation of benefit based on scientific evidence or prior treatment response. Prescribers are responsible for determining whether PPI use is absolutely or conditionally indicated and, when uncertainty exists, to incorporate patient perspectives into PPI decision making. We collaboratively outlined a high-level "process map" of the conceptual approach to de-prescribing PPIs in a clinical setting. We identified the following 3 key domains that required BPA guidance: documentation of PPI indication; identifying suitable candidates for consideration of de-prescribing; and optimizing successful de-prescribing. Co-authors drafted 1 or more potential BPAs, supported by literature review, for each domain. All co-authors reviewed, edited, and selected or rejected draft BPAs for inclusion in the final list submitted to the American Gastroenterological Association Governing Board. Because this was not a systematic review, we did not carry out a formal rating of the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: All patients taking a PPI should have a regular review of the ongoing indications for use and documentation of that indication. This review should be the responsibility of the patient's primary care provider. BEST PRACTICE ADVICE 2: All patients without a definitive indication for chronic PPI should be considered for trial of de-prescribing. BEST PRACTICE ADVICE 3: Most patients with an indication for chronic PPI use who take twice-daily dosing should be considered for step down to once-daily PPI. BEST PRACTICE ADVICE 4: Patients with complicated gastroesophageal reflux disease, such as those with a history of severe erosive esophagitis, esophageal ulcer, or peptic stricture, should generally not be considered for PPI discontinuation. BEST PRACTICE ADVICE 5: Patients with known Barrett's esophagus, eosinophilic esophagitis, or idiopathic pulmonary fibrosis should generally not be considered for a trial of de-prescribing. BEST PRACTICE ADVICE 6: PPI users should be assessed for upper gastrointestinal bleeding risk using an evidence-based strategy before de-prescribing. BEST PRACTICE ADVICE 7: Patients at high risk for upper gastrointestinal bleeding should not be considered for PPI de-prescribing. BEST PRACTICE ADVICE 8: Patients who discontinue long-term PPI therapy should be advised that they may develop transient upper gastrointestinal symptoms due to rebound acid hypersecretion. BEST PRACTICE ADVICE 9: When de-prescribing PPIs, either dose tapering or abrupt discontinuation can be considered. BEST PRACTICE ADVICE 10: The decision to discontinue PPIs should be based solely on the lack of an indication for PPI use, and not because of concern for PAAEs. The presence of a PAAE or a history of a PAAE in a current PPI user is not an independent indication for PPI withdrawal. Similarly, the presence of underlying risk factors for the development of an adverse event associated with PPI use should also not be an independent indication for PPI withdrawal.

Gastrinoma and Zollinger Ellison syndrome: A roadmap for the management between new and old therapies

Zollinger-Ellison syndrome (ZES) associated with pancreatic or duodenal gastrinoma is characterized by gastric acid hypersecretion, which typically leads to gastroesophageal reflux disease, recurrent peptic ulcers, and chronic diarrhea. As symptoms of ZES are nonspecific and overlap with other gastrointestinal disorders, the diagnosis is often delayed with an average time between the onset of symptoms and final diagnosis longer than 5 years. The critical step for the diagnosis of ZES is represented by the initial clinical suspicion. Hypergastrinemia is the hallmark of ZES; however, hypergastrinemia might recognize several causes, which should be ruled out in order to make a final diagnosis. Gastrin levels > 1000 pg/mL and a gastric pH below 2 are considered to be diagnostic for gastrinoma; some specific tests, including esophageal pH-recording and secretin test, might be useful in selected cases, although they are not widely available. Endoscopic ultrasound is very useful for the diagnosis and the local staging of the primary tumor in patients with ZES, particularly in the setting of multiple endocrine neoplasia type 1. Some controversies about the management of these tumors also exist. For the localized stage, the combination of proton pump inhibitory therapy, which usually resolves symptoms, and surgery, whenever feasible, with curative intent represents the hallmark of gastrinoma treatment. The high expression of somatostatin receptors in gastrinomas makes them highly responsive to somatostatin analogs, supporting their use as anti-proliferative agents in patients not amenable to surgical cure. Other medical options for advanced disease are super-imposable to other neuroendocrine neoplasms, and studies specifically focused on gastrinomas only are scant and often limited to case reports or small retrospective series. The multidisciplinary approach remains the cornerstone for the proper management of this composite disease. Herein, we reviewed available literature about gastrinoma-associated ZES with a specific focus on differential diagnosis, providing potential diagnostic and therapeutic algorithms.

The role of autofluorescence, photodynamic diagnosis and Photodynamic therapy in malignant tumors of the duodenum

This article presents the current state of knowledge and a review of the literature in terms of the prevalence, etiopathogenesis, differential diagnosis, management, prognosis, and treatment of malignant tumors of the duodenum. The role of autofluorescence and photodynamic diagnosis as an emerging treatment method for rarely o ccurring duodenal malignant neoplasms .. We selected publications which can be found in databases such as The National Center for Biotechnology Information, U.S. National Library of Medicine (PubMed), The American Chemical Society, The American Association of Pharmaceutical Sciences and The American Society for Photobiology and The Canada Institute for Scientific and Technical Information.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Medical Management of Pancreatic Neuroendocrine Tumors

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.

The Clinician's Guide to Proton-Pump Inhibitor Discontinuation

There is increasing concern among patients and health care providers about the associations between PPI use and a multitude of potential adverse outcomes. Therefore, clinicians need to have a rational approach both to identifying PPI users who may not have an ongoing indication for their use and on how to encourage discontinuation of unnecessary PPI use. In this paper, we will provide a detailed review of the specific indications where the benefits of ongoing PPI use is of questionable value and will review the evidence on how to maximize the likelihood of being able to successfully discontinue PPI use while minimizing symptom recurrence.

Adverse Effects of Proton Pump Inhibitors on Platelet Count: A Case Report and Review of the Literature

Proton pump inhibitors (PPIs) are the most effective and preferred class of drugs used to treat peptic ulcer disease, gastroesophageal reflux disease, and other diseases associated with increased production of gastric acid. PPIs in general have an excellent long-term safety profile and are well-tolerated. However, studies have shown some adverse reactions (e.g., osteoporosis, Clostridium difficile-associated diarrhea, Vitamin B12 and iron deficiency, and acute interstitial nephritis) on long-term PPI use. Thrombocytopenia attributed to use of PPIs has been described in a few case reports and a retrospective study. In this case report, we describe a case of PPI-induced thrombocytopenia. In our patient, thrombocytopenia immediately developed after the initiation of PPI on two separate occasions and resolved after its discontinuation. The strong association found in our case implies the potential role of PPI in causing this rare but serious adverse reaction. Based on this case report and the observation from other studies, a PPI-induced adverse event should be considered as a possible etiology for new-onset idiopathic thrombocytopenia.

Discontinuing Long-Term PPI Therapy: Why, With Whom, and How?

Proton pump inhibitors (PPIs) are among the most widely used class of drugs prescribed over the long term in all of clinical medicine with 8-10% of ambulatory adults have been prescribed a PPI in the past 30 days. However, numerous studies have raised doubts about the long term safety of PPI use. The purpose of this review is threefold: (i) To provide an overview of the current evidence demonstrating associations between PPI use and adverse health outcomes and the likelihood of the associations being causal (Why?); (ii) To be able to identify long-term PPI users in whom the intensity of PPI therapy could be reduced or in whom PPIs could be eliminated outright (Who?); and (iii) To provide strategies on how to reduce or stop chronic PPI therapy while maintaining symptom control and reducing the risk for symptom or upper GI disease recurrence (How?).

Catching the Zebra: Clinical Pearls and Pitfalls for the Successful Diagnosis of Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome (ZES) results from an ectopic gastrin-secreting tumor leading to peptic ulcer disease, reflux, and chronic diarrhea. While early recognition portends an excellent prognosis with >80% survival at 15 years, symptoms are often nonspecific making the diagnosis difficult to establish. Diagnosis involves a series of tests, including fasting gastrin, gastric pH, chromogranin A, and secretin stimulation. Performing these tests in the correct sequence and at the proper time is essential to avoid inaccurate results. Tumor localization is equally nuanced. Although providers have classically used ¹¹¹indium-radiolabeled octreotide with somatostatin receptor scintigraphy to evaluate tumor size and metastases, recent studies have shown superior results with newer imaging modalities. In particular, ⁶⁸gallium (⁶⁸Ga)-labeled somatostatin radiotracers (i.e., ⁶⁸Ga-DOTATOC, ⁶⁸Ga-DOTANOC and ⁶⁸Ga-DOTATATE) used with positron emission tomography/computed tomography can provide excellent results. Endoscopic ultrasound is another useful modality, particularly in patients with ZES in the setting of multiple endocrine neoplasia type 1. This review aims to provide clinicians with an overview of ZES with a focus on both clinical presentation and the proper utilization of the various biochemical and imaging tests available.

Zollinger-Ellison Syndrome: A Rare Case of Chronic Diarrhea

Zollinger-Ellison syndrome (ZES) is caused by hypersecretion of gastrin from duodenal or pancreatic gastrinomas. We report a case of a 57-year-old female who presented with chronic diarrhea. CT abdomen showed multiple liver masses. Liver biopsy suggested metastatic well-differentiated neuroendocrine tumor. Serum gastrin level was markedly elevated. MRI abdomen, somatostatin receptor scintigraphy and endoscopic ultrasound failed to reveal primary site of the tumor. Upper gastrointestinal endoscopy showed hyperplastic gastric folds and multiple duodenal ulcers consistent with ZES. Patient was started on high-dose omeprazole and octreotide resulting in improvement in diarrhea.

The Indications, Applications, and Risks of Proton Pump Inhibitors

BACKGROUND

Proton pump inhibitors (PPI) are the most effective drugs for inhibiting gastric acid secretion. They have been in clinical use for more than 25 years, In 2014, 3.475 billion daily defined doses (DDD) of PPI were prescribed in Germany. This high number alone calls for a critical analysis of the spectrum of indications for PPI and their potential adverse effects.

METHODS

This review is based on pertinent publications retrieved by a selective search in the PubMed and Cochrane Library databases, with particular emphasis on randomized, prospective multicenter trials, cohort studies, case-control studies, and meta-analyses.

RESULTS

The inhibition of gastric acid secretion with PPI is successfully used for the treatment of gastroesophageal reflux disease and of gastric and duodenal ulcers, for the secondary prevention of gastroduodenal lesions that have arisen under treatment with nonsteroidal anti-inflammatory drugs and acetylsalicylic acid, and for the prevention of recurrent hemorrhage from ulcers after successful endoscopic hemostasis. PPI are given along with practically all antibiotic regimens for the eradication of Helicobacter pylori infection. The number of prescriptions for PPI has risen linearly over the past 25 years. As there has been no broadening of indications, one may well ask whether the current, extensive use of PPI is justified. There is evidence that patients taking PPI are at greater risk for fractures. Moreover, the vitamin B12 level should be checked occasionally in all patients taking PPI.

CONCLUSION

PPI are among the more effective drugs for the treatment of diseases associated with gastric acid. In view of their cost and potential adverse effects, they should only be prescribed for scientifically validated indications.

Gastric Hypersecretory States: Investigation and Management

OPINION STATEMENT

Hypersecretory conditions affecting the stomach account for significant morbidity and mortality manifested in some cases with peptic ulcer, gastrointestinal hemorrhage, and/or gastroesophageal reflux disease (GERD). The diagnosis of gastric acid hypersecretory states can be challenging and relies on the use of quantitative assays to measure gastric acid secretion and serum gastrin. The most common etiology for hypergastrinemia is the use of potent gastric acid inhibitors such as the proton pump inhibitors. The differential diagnosis of this condition is of critical importance, and will dictate management decisions. Conditions such as atrophic gastritis are relatively benign and can lead to hypergastrinemia without the presence of gastric acid hypersecretion. Zollinger-Ellison syndrome, on the other hand, causes hypergastrinemia with profound gastric acid hypersecretion [1]. More common causes of hypergastrinemia include gastric outlet obstruction, ileus, and chronic renal failure [2]. In most cases, proton pump inhibitors will be used to manage these conditions. In some instances, surgical therapy may be required. This chapter will review the important clinical causes of gastric acid hypersecretion and provide insights to the best medical management options to better care for patients with these disorders.

Pharmacotherapy of Zollinger-Ellison syndrome

INTRODUCTION

The role of pharmacotherapy in the management of patients with Zollinger-Ellison syndrome (ZES) is often equated with the medical management of acid hypersecretion. However, pharmacotherapy is also increasingly involved in the other management areas of these patients.

AREAS COVERED

This paper reviews the role of pharmacotherapy in all aspects of the management of patients with ZES. Newer aspects are emphasized. This includes the difficulty of diagnosing ZES in patients taking proton pump inhibitors. Also covered is the role of pharmacotherapy in controlling acid hypersecretion and other hormonal hypersecretory states these patients may develop, including hyperparathyroidism in patients with multiple endocrine neoplasia type 1 and ZES; tumor localization; and the treatment of advanced metastatic disease. The last includes chemotherapy, liver-directed therapies, biotherapy (somatostatin/interferon), peptide radio-receptor therapy and molecular-targeted therapies including the use of mTor inhibitors (everolimus) and tyrosine kinase inhibitors (sunitinib).

EXPERT OPINION

Pharmacotherapy is now involved in all aspects of the management of patients with ZES, with the result that ZES has progressed from being considered an entirely surgical disease initially to the present where medical treatment plays a major role in almost all aspects of the management of these patients.

Zollinger-Ellison syndrome: presentation, response to therapy, and outcome

BACKGROUND

Recent series describing the clinical presentation, response to therapy, and long-term outcome of Zollinger-Ellison syndrome are limited.

AIMS

To assess the clinical characteristics and long-term outcome of patients with Zollinger-Ellison syndrome.

METHODS

Over a 20-year period, patients with Zollinger-Ellison syndrome were enrolled in a prospective trial evaluating the efficacy of lansoprazole. Following dose stabilization, patients were followed on a 6-monthly basis with interval history, physical examination, endoscopy with gastric biopsies, gastric acid analysis and laboratory studies.

RESULTS

72 patients (mean age 54±12 years, % male 58%, % Caucasian 69%) were prospectively enrolled. The clinical presentation was stereotypical for Zollinger-Ellison syndrome. Symptoms had been reported for a median of 9 years prior to diagnosis. Cross-sectional abdominal imaging was often negative for demonstrable tumour. All patients had gastric acid hypersecretion controlled with variable doses of lansoprazole (median dose 60 mg/day, range 15-480 mg/day). The median survival from the time of diagnosis was 6.6 years; only two of 19 deaths were due to metastatic gastrinoma.

CONCLUSIONS

The clinical presentation of Zollinger-Ellison syndrome was similar to prior reports. Acid hypersecretion was controlled in all patients with variable doses of lansoprazole. Long-term survival was principally related to underlying co-morbidity.

Gastric acid hypersecretory states: recent insights and advances

Gastric acid hypersecretory states are characterized by basal hypersecretion of gastric acid and historically include disorders associated with hypergastrinemia, hyperhistaminemia, and those of unknown etiology. Although gastric acid secretion is infrequently measured, it is important to recognize the role of gastric hypersecretion in the symptoms of these disorders because they share several features of pathogenesis and treatment. In this article, recent important articles reporting insights into their diagnosis, pathogenesis, and treatment are reviewed. Particular attention is paid to Zollinger-Ellison syndrome, because it has the most extreme acid hypersecretion of this group of disorders and because numerous recent articles deal with various aspects of the diagnosis, molecular pathogenesis, and treatment of the gastrinoma itself or the acid hypersecretion. Two new hypersecretory disorders are reviewed: rebound acid hypersecretion after the use of proton pump inhibitors and acid hypersecretion with cysteamine treatment in children with cystinosis.

PPI-delayed diagnosis of gastrinoma: oncologic victim of pharmacologic success

Functional neuroendocrine tumors are often low-grade malignant neoplasms that can be cured by surgery if detected early, and such detection may in turn be accelerated by the recognition of neuropeptide hypersecretion syndromes. Uniquely, however, relief of peptic symptoms induced by hypergastrinemia is now available from acid-suppressive drugs such as proton-pump inhibitors (PPIs). Here we describe a clinical case in which time to diagnosis from the onset of peptic symptoms was delayed more than 10 years, in part reflecting symptom masking by continuous prescription of the PPI omeprazole. We propose diagnostic criteria for this under-recognized new clinical syndrome, and recommend that physicians routinely measure serum gastrin levels in persistent cases of PPI-dependent dyspepsia unassociated with H. pylori.

Treatment strategies for Zollinger-Ellison syndrome

BACKGROUND

Zollinger-Ellison syndrome (ZES) is a rare disorder caused by tumor secretion of the hormone gastrin, which results in gastric acid hypersecretion and secondarily complicated peptic ulcer and diarrhea. Until the development of H(2)-receptor antagonists and later proton pump inhibitors (PPIs), the disease was virulent, often associated with ulcer-related mortality, and the mainstay of treatment was total gastrectomy.

OBJECTIVE

To evaluate current approaches to diagnosis and therapy, focusing on the role of PPIs.

METHODS

An extensive literature search through PubMed using the search term 'Zollinger-Ellison syndrome' from 1964 to the present was performed. Primary articles were identified, and pertinent articles obtained from the reference lists were also examined.

RESULTS/CONCLUSIONS

The clinical manifestations of ZES are well described, but overlaps with other more common disorders delay diagnosis. The use of abdominal imaging with somatostatin receptor scintigraphy and endoscopic ultrasound has improved tumor staging. PPI therapy is remarkably effective in controlling gastric acid hypersecretion, thereby reducing morbidity and potential mortality of this syndrome. The dose of drug necessary to control symptoms is highly variable but, even when used in high doses for prolonged periods of time, the disease remained controlled with very few drug-related side effects.

Gastrointestinal neuroendocrine tumors: pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) have long fascinated clinicians and investigators despite their relative rarity. Their clinical presentation varies depending on whether the tumor is functional or not, and also according to the specific hormonal syndrome produced. Tumors may be sporadic or inherited, but little is known about their molecular pathology, especially the sporadic forms. Chromogranin A appears to be the most useful serum marker for diagnosis, staging, and monitoring. Initially, therapy should be directed at the hormonal syndrome because this has the major initial impact on the patient's health. Most PETs are relatively indolent but ultimately malignant, except for insulinomas, which predominantly are benign. Surgery is the only modality that offers the possibility of cure, although it generally is noncurative in patients with Zollinger-Ellison syndrome or nonfunctional PETs with multiple endocrine neoplasia-type 1. Preoperative staging of disease extent is necessary to determine the likelihood of complete resection although debulking surgery often is believed to be useful in patients with unresectable tumors. Once metastatic, biotherapy is usually the first modality used because it generally is well tolerated. Systemic or regional therapies generally are reserved until symptoms occur or tumor growth is rapid. Recently, a number of newer agents, as well as receptor-directed radiotherapy, are being evaluated for patients with advanced disease. This review addresses a number of recent advances regarding the molecular pathology, diagnosis, localization, and management of PETs including discussion of peptide-receptor radionuclide therapy and other novel antitumor approaches. We conclude with a discussion of future directions and unsettled problems in the field.

Proton pump inhibitors: an update of their clinical use and pharmacokinetics

BACKGROUND

Proton pump inhibitors (PPIs) represent drugs of first choice for treating peptic ulcer, Helicobacter pylori infection, gastrooesophageal reflux disease, nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal lesions (complications), and Zollinger-Ellison syndrome.

RESULTS

The available agents (omeprazole/esomeprazole, lansoprazole, pantoprazole, and rabeprazole) differ somewhat in their pharmacokinetic properties (e.g., time-/dose-dependent bioavailability, metabolic pattern, interaction potential, genetic variability). For all PPIs, there is a clear relationship between drug exposure (area under the plasma concentration/time curve) and the pharmacodynamic response (inhibition of acid secretion). Furthermore, clinical outcome (e.g., healing and eradication rates) depends on maintaining intragastric pH values above certain threshold levels. Thus, any changes in drug disposition will subsequently be translated directly into clinical efficiency so that extensive metabolizers of CYP2C19 will demonstrate a higher rate of therapeutic nonresponse.

CONCLUSIONS

This update of pharmacokinetic, pharmacodynamic, and clinical data will provide the necessary guide by which to select between the various PPIs that differ-based on pharmacodynamic assessments-in their relative potencies (e.g., higher doses are needed for pantoprazole and lansoprazole compared with rabeprazole). Despite their well-documented clinical efficacy and safety, there is still a certain number of patients who are refractory to treatment with PPIs (nonresponder), which will leave sufficient space for future drug development and clinical research.

Effects of esomeprazole on acid output in patients with Zollinger-Ellison syndrome or idiopathic gastric acid hypersecretion

OBJECTIVES

To evaluate the efficacy and safety of oral esomeprazole in the control of gastric acid hypersecretion in patients with hypersecretory states.

METHODS

In this 12-month, open-label, multicenter study, acid output (AO) was evaluated at baseline, day 10, and months 3, 6, and 12. The starting dose of esomeprazole was 40 mg or 80 mg twice daily. On day 10, patients with controlled AO were maintained on the same dose, while those with uncontrolled AO had their doses increased (maximum dose 240 mg/day) until control was attained. Esophagogastroduodenoscopy (EGD) was performed at baseline and at 6 and 12 months. Safety and tolerability were assessed throughout the study by EGD, gastric analysis, and adverse events.

RESULTS

Twenty-one patients (19 with Zollinger-Ellison syndrome [ZES], 2 with idiopathic gastric acid hypersecretion [IGH]) completed the study. Of the 20 patients with controlled AO at day 10, 18 (90%) had sustained AO control for the rest of the study. At 12 months, AO was controlled in 14 of 16 patients receiving esomeprazole 40 mg twice daily, in all 4 patients receiving esomeprazole 80 mg twice daily, and in the 1 patient receiving esomeprazole 80 mg 3 times daily. At 6 and 12 months, no patient had endoscopic evidence of mucosal disease. Esomeprazole was well tolerated; 1 patient had a serious adverse event (hypomagnesemia) attributed to treatment that resolved with magnesium supplementation during continued treatment.

CONCLUSION

Esomeprazole in appropriately titrated doses controls AO over 12 months in patients with hypersecretory states and is well tolerated.

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.

Comparative tolerability of 2- and 15-minute intravenous infusions of pantoprazole

PURPOSE

The safety and tolerability of 80 mg i.v. pantoprazole administered as a 2-minute versus a 15-minute infusion were studied.

METHODS

In a single-blind, randomized, multiple-dose, parallel-group study, 48 healthy participants (ages 18-45 years) were randomly assigned for treatment with 80 mg i.v. pantoprazole infused for 2 or 15 minutes once daily for seven days. A blinded evaluator assessed the injection site for phlebitis and infiltration on a 5-point scale at specified intervals. Participants completed the visual analogue scale (VAS) for pain and burning at baseline and at 5 minutes postinjection.

RESULTS

More than 99% of the preinfusion and postinfusion infiltration scores and >95% of the phlebitis scores were rated as zero in 48 healthy participants. A total of 7 infiltration scores (1%) and 72 postinfusion phlebitis scores (5%) of greater than 0 were recorded, all of which were mild in nature. Forty-one phlebitis scores of 1 and 1 score of 2 were from 12 participants in the 2-minute group, and 20 scores of 1 and 10 scores of 2 were from 8 participants in the 15-minute group. VAS assessments showed that the perception of pain and burning was not greater in the 2-minute group. There were no significant differences in adverse events between the two groups.

CONCLUSION

The safety and tolerability profiles of i.v. pantoprazole administered as a 2-minute infusion were similar to those of the 15-minute infusion. This protocol may result in the savings of staff time with no additional discomfort to the patient.