Intravenous pantoprazole rapidly controls gastric acid hypersecretion in patients with Zollinger-Ellison syndrome

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.

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.

Exposure to proton pump inhibitors and risk of pancreatic cancer: a meta-analysis

Objectives: To estimate the pancreatic cancer risk among subjects exposed versus not exposed to proton pump inhibitors.Methods: The authors searched PubMed, EMBASE, Scopus, Cochrane Library, and clinicaltrials.gov to identify relevant studies. The authors quantified pancreatic cancer risk among subjects exposed versus not exposed to PPIs, expressed as the pooled (adjusted) odds ratio (OR/aOR) and 95% confidence interval (95%CI) in overall and sensitivity analyses.Results: One randomized trial, two cohort, four case-control, and five nested case-control studies with 700,178 subjects (73,985 cases; 626,193 controls) were retained. PPI exposure was associated with pancreatic cancer risk (OR = 1.75, 95%CI = 1.12-2.72, I2 = 99%); confirmed in sensitivity analyses for high-quality studies, observational studies, case-control studies, studies with pancreatic cancer as the primary outcome, and in sensitivity analyses for diabetes and obesity but not for pancreatitis and smoking. This association was independent of the duration and Defined Daily Dose of PPI exposure. Rabeprazole had a singular significant association with pancreatic cancer (OR = 5.40, 95%CI = 1.98-14.703, I2 = 87.9%).Conclusion: The class of PPIs is associated with a 1.75-fold increase in pancreatic cancer risk, confirmed in sensitivity analyses.

Gamma Emitters in Pancreatic Endocrine Tumors Imaging in the PET Era: Is there a Clinical Space for 99mTc-peptides?

Background:

Pancreatic Neuroendocrine Tumors (PNETs) are rare neoplasms, sporadic or familial, even being part of a syndrome. Their diagnosis is based on symptoms, hormonal disorders or may be fortuitous. The role of Nuclear Medicine is important, mainly because of the possibility of a theranostic strategy. This approach is allowed by the availability of biochemical agents, which may be labeled with radionuclides suitable for diagnostic or therapeutic purposes, showing almost identical pharmacokinetics. The major role for radiopharmaceuticals is connected with radiolabeled Somatostatin Analogues (SSA), since somatostatin receptors are highly expressed on some of the neoplastic cell types.

Discussion:

Nowadays, in the category of radiolabeled SSA, although 111In-pentetreotide, firstly commercially proposed, is still used, the best choice for diagnosis is related to the so called DOTAPET radiotracers labeled with 68-Gallium (Ga), such as 68Ga-DOTATATE, 68Ga-DOTANOC, and 68Ga-DOTATOC. More recently, labeling with 64-Copper (Cu) (64Cu-DOTATATE) has also been proposed. In this review, we discuss the clinical interest of a SAA (Tektrotyd©) radiolabeled with 99mTc, a gamma emitter with better characteristics, with respect to 111Indium, radiolabeling Octreoscan ©. By comparing both pharmacokinetics and pharmacodynamics of Octreoscan©, Tektrotyd© and PET DOTA-peptides, on the basis of literature data and of our own experience, we tried to highlight these topics to stimulate further studies, individuating actual clinical indications for all of these radiotracers.

Conclusion:

In our opinion, Tektrotyd© could already find its applicative dimension in the daily practice of NETs, either pancreatic or not, at least in centers without a PET/CT or a 68Ga generator. Because of wider availability, a lower cost, and a longer decay, compared with respect to peptides labeled with 68Ga, it could be also proposed, in a theranostic context, for a dosimetry evaluation of patients undergoing Peptide Receptor Radionuclide Therapy (PRRT), and for non-oncologic indications of radiolabelled SSA. In this direction, and for a more rigorous cost/effective evaluation, more precisely individuating its clinical role, further studies are needed.

Advances and Current Concepts in the Medical Management of Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare and heterogeneous group of tumors presenting as localised or metastatic disease and in a subset with distinct clinical syndromes. Treatment is aimed at controlling the functional syndrome, eradicating the tumor, and/or preventing further tumor growth. Surgery is the treatment of choice in removing the primary tumor and/or reducing tumor burden but cannot be applied to all patients. Somatostatin analogs (SS-analogs) obtain control of functional syndromes in the majority of GEP-neuroendocrine tumors (NETs); phase III trials have shown that SS-analogs can be used as first-line antiproliferative treatment in patients with slow-growing GEP-NETs. The role of the recently approved serotonin inhibitor, telotristat ethyl, and gastrin receptor antagonist, netazepide, is evolving. Streptozotocin-based chemotherapy has been used for inoperable or progressing pancreatic NENs but the orally administered combination of capecitabine/temozolomide is becoming more popular due to its better tolerability and potential effect in other GEP-NENs. Phase III trials have shown efficacy of molecular targeted therapies in GEP-NETs and of radionuclide treatment in patients with midgut carcinoid tumors expressing somatostatin receptors. Most patients will develop disease progression necessitating further therapeutic options. A combination of currently available treatments along with the molecular signature of each tumor will guide future treatment.

Pantoprazole IV

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ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: Pre- and Perioperative Therapy in Patients with Neuroendocrine Tumors

Neuroendocrine tumors of the small intestine are the most common causes of the carcinoid syndrome. Carcinoid heart disease occurs in more than half of the patients with the carcinoid syndrome. Patients with carcinoid heart disease who need to undergo surgery should also undergo preoperative evaluation by an expert cardiologist. Treatment with long-acting somatostatin analogs aims at controlling the excessive hormonal output and symptoms related to the carcinoid syndrome and at preventing a carcinoid crisis during interventions. Patients with a gastrinoma require pre- and postoperative treatment with high doses of proton pump inhibitors. Patients with a glucagonoma require somatostatin analog treatment and nutritional supplementation. Patients with a VIPoma also require somatostatin analog treatment and intravenous fluid and electrolyte therapy. Insulinoma patients generally require intravenous glucose infusion prior to operation. In patients with localized operable insulinoma, somatostatin analog infusion should only be considered after the effect of this therapy has been electively studied.

Effective and safe proton pump inhibitor therapy in acid-related diseases - A position paper addressing benefits and potential harms of acid suppression

BACKGROUND

The introduction of proton pump inhibitors (PPIs) into clinical practice has revolutionized the management of acid-related diseases. Studies in primary care and emergency settings suggest that PPIs are frequently prescribed for inappropriate indications or for indications where their use offers little benefit. Inappropriate PPI use is a matter of great concern, especially in the elderly, who are often affected by multiple comorbidities and are taking multiple medications, and are thus at an increased risk of long-term PPI-related adverse outcomes as well as drug-to-drug interactions. Herein, we aim to review the current literature on PPI use and develop a position paper addressing the benefits and potential harms of acid suppression with the purpose of providing evidence-based guidelines on the appropriate use of these medications.

METHODS

The topics, identified by a Scientific Committee, were assigned to experts selected by three Italian Scientific Societies, who independently performed a systematic search of the relevant literature using Medline/PubMed, Embase, and the Cochrane databases. Search outputs were distilled, paying more attention to systematic reviews and meta-analyses (where available) representing the best evidence. The draft prepared on each topic was circulated amongst all the members of the Scientific Committee. Each expert then provided her/his input to the writing, suggesting changes and the inclusion of new material and/or additional relevant references. The global recommendations were then thoroughly discussed in a specific meeting, refined with regard to both content and wording, and approved to obtain a summary of current evidence.

RESULTS

Twenty-five years after their introduction into clinical practice, PPIs remain the mainstay of the treatment of acid-related diseases, where their use in gastroesophageal reflux disease, eosinophilic esophagitis, Helicobacter pylori infection, peptic ulcer disease and bleeding as well as, and Zollinger-Ellison syndrome is appropriate. Prevention of gastroduodenal mucosal lesions (and symptoms) in patients taking non-steroidal anti-inflammatory drugs (NSAIDs) or antiplatelet therapies and carrying gastrointestinal risk factors also represents an appropriate indication. On the contrary, steroid use does not need any gastroprotection, unless combined with NSAID therapy. In dyspeptic patients with persisting symptoms, despite successful H. pylori eradication, short-term PPI treatment could be attempted. Finally, addition of PPIs to pancreatic enzyme replacement therapy in patients with refractory steatorrhea may be worthwhile.

CONCLUSIONS

Overall, PPIs are irreplaceable drugs in the management of acid-related diseases. However, PPI treatment, as any kind of drug therapy, is not without risk of adverse effects. The overall benefits of therapy and improvement in quality of life significantly outweigh potential harms in most patients, but those without clear clinical indication are only exposed to the risks of PPI prescription. Adhering with evidence-based guidelines represents the only rational approach to effective and safe PPI therapy. Please see related Commentary: doi: 10.1186/s12916-016-0724-1 .

Medical management of secretory syndromes related to gastroenteropancreatic neuroendocrine tumours

Although recent epidemiological evidence indicates that the prevalence of non-functioning gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) is rising, a significant number of GEP-NETs still present with symptoms related to the secretion of biologically active substances leading to the development of distinct clinical syndromes. In the past, these syndromes were associated with substantial morbidity and mortality due to the lack of specific therapies; however, since the introduction of long-acting somatostatin analogues and medications such as proton pump inhibitors, their control has been greatly improved. As a result, nowadays, the main cause of morbidity and mortality in GEP-NETs is mostly directly related to tumour growth and the extent of metastatic disease. However, in some patients with functioning tumours and extensive disease, control of the secretory syndrome still remains problematic, necessitating the employment of several cytoreductive techniques, which may not always be sufficient. Recently, new agents directed against tumour growth, or exerting increased binding activity to receptors expressed in these tumours, or interfering with the synthetic pathway of some of the compounds secreted by these tumours, have been developed. Since there are no specific guidelines addressing the totality of the management of the secretory syndromes related to GEP-NETs, this review aims at critically analysing the medical management of previously recognised secretory syndromes; it also addresses areas of uncertainty, assesses the newer therapeutic developments and also addresses recently described but poorly characterised secretory syndromes related to GEP-NETs.

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.

Conservative management and parenchyma-sparing resections of pancreatic neuroendocrine tumors: Literature review

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) are uncommon entities. pNETs are often small, slow growing, clinically silent neoplasms. However, they have an almost unpredictable biological behaviour with a not negligible malignant potential. Surgery still represents the treatment of choice, but the high morbidity associated to the enucleation or the formal pancreatectomy should be considered in the decision of the proper treatment. Management of these neoplasms is still debated, and indications for a conservative observational approach and for parenchyma sparing resections are not yet standardized.

METHOD

We review the state of art on the indications for the conservative management of pNETs. Searches on MEDLINE database were performed to identify articles reporting prognostic systems, biochemical screening, observational management, medical treatment and surgical strategies for pNETs.

DISCUSSION

Currently, an accurate 'wait-and-see' policy is recommended by the European Neuroendocrine Tumor Society (ENETS) only for non-functioning pNETs (NF-pNETs) <2 cm. A biochemical screening, based on sampling of serum levels of pancreatic polypeptide (PP) and chromogranin A, can address to early conservative surgery for MEN-1 associated NF-pNETs <2 cm to prevent their malignant transformation. The subtotal (80%) distal pancreatectomy first proposed by Thompson, often with the enucleation of possible pancreatic head tumors, still represents a good compromise between oncological radicality and prevention of pancreatic endocrine/exocrine insufficiency caused by standard radical resections for the treatment of inherited syndromes associated with NF-pNETs >2 cm and symptomatic F-pNETs of any size.

CONCLUSION

More studies are needed to further clarify and predict the biologic behaviour of pNETs and increase the indications for conservative observational management and parenchyma sparing pancreas resections.

The comparison of extemporaneous preparations of omeprazole, pantoprazole oral suspension and intravenous pantoprazole on the gastric pH of critically ill-patients

Background:

Stress-related mucosal disease occurs in many critically ill-patients within 24 h of admission. Proton pump inhibitor therapy has been documented to produce more potent inhibition of gastric acid secretion than histamine 2 receptor antagonists. This study aimed to compare extemporaneous preparations of omeprazole, pantoprazole oral suspension and intravenous (IV) pantoprazole on the gastric pH in intensive care unit patients.

Materials and Methods:

This was a randomized single-blind-study. Patients of ≥ 16 years of age with a nasogastric tube, who required mechanical ventilation for ≥ 48 h, were eligible for inclusion. The excluded patients were those with active gastrointestinal bleeding, known allergy to omeprazole and pantoprazole and those intolerant to the nasogastric tube. Fifty-six patients were randomized to treatment with omeprazole suspension 2 mg/ml (40 mg every day), pantoprazole suspension 2 mg/ml (40 mg every day) and IV pantoprazole (40 mg every day) for up to 14 days. Gastric aspirates were sampled before and 1-2.5 h after the drug administration for the pH measurement using an external pH meter. Data were analyzed using SPSS (version 21.0).

Results:

In this study, 56 critically ill-patients (39 male, 17 female, mean age: 61.5 ± 15.65 years) were followed for the control of the gastric pH. On each of the 14 trial days the mean of the gastric pH alteration was significantly higher in omeprazole and pantoprazole suspension-treated patients than in IV pantoprazole-treated patients (P < 0.001).

Conclusion:

Omeprazole and pantoprazole oral suspension are more effective than IV pantoprazole in increasing the gastric pH.

Practical management and treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (NETs) are uncommon disease, about which little is known. Pancreatic NETs are usually slow growing and their malignant potential are often underestimated. The management of this disease poses a challenge because of the heterogeneous clinical presentation and varying degrees of aggressiveness. Recently, several guidelines for the management of pancreatic NETs have been established and help to devise clinical strategy. In the treatment algorithms, however, a lot of uncertain points are included. Practical treatment decisions of pancreatic NETs are still sometimes made in a patient- and/or physicians-oriented manner. The tumor grading system proposed by the European Neuroendocrine Tumor Society (ENETS) gives important prognostic information, however, the implication of grading regarding medical treatment strategies to choose has not yet been clarified. Moreover, the place of surgical treatment is unclear in the overall management course of advanced pancreatic NETs. In some cases, practical management and treatment have to be individualized depending on predominant symptoms, tumor spread, and general health of the patients. Current issues and a few points to make a strategy in the management of pancreatic NETs would be reviewed.

Gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Studying menin and its complex interrelationship with gastrin may provide insight into tumor biology at the clinical level and in terms of basic cell biology (eg, the role of the epigenome in neuroendocrine cell proliferation), and lead to potential consideration of other targets that are known candidates for molecular-based therapies in other adenocarcinomas.

Practical guide to supportive care of patients with functional neuroendocrine tumors

Supportive care of patients with functional neuroendocrine tumors (NETs) has evolved to include the use of multiple targeted agents to control paraneoplastic states and newer surgical and interventional radiologic techniques to reduce tumor bulk. Challenges encountered by the clinician are the recognition of specific symptom complexes, selecting the relevant laboratory tests and radiologic/scintigraphic scans, and the timing of intervention(s). Individual variables such as the severity of symptoms in the context of primary and metastatic disease sites, tumor bulk, comorbidities, and previous treatment are factors determining the prioritization of specific treatment regimens for patients with functional NETs. Symptoms such as flushing, secretory diarrhea, hypercalcemia, hyper /hypoglycemia, hypercortisolism, and peptic ulcers should improve with decreasing the elevated amino acid and/or peptide levels produced by NETs. These paraneoplastic symptoms may be accompanied by complaints related to tumor burden such as fatigue, pain, early satiety, anorexia, weight loss, night sweats, and/or symptoms secondary to adverse drug effects such as mucositis, dysgeusia, diarrhea, rash, hypertension, and myelosuppression. Developing a comprehensive continuum of care plan early in disease management assists in controlling the presenting signs and symptoms, and in minimizing disease- and/or treatment-related side effects. This guide serves as a framework to manage the signs and symptoms of metastatic functional neuroendocrine tumors.

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.

Pancreatic neuroendocrine tumors: biology, diagnosis,and treatment

Pancreatic neuroendocrine tumors (PNETs), a group of endocrine tumors arising in the pancreas, are among the most common neuroendocrine tumors. The genetic causes of familial and sporadic PNETs are somewhat understood, but their molecular pathogenesis remains unknown. Most PNETs are indolent but have malignant potential. The biological behavior of an individual PNET is unpredictable; higher tumor grade, lymph node and liver metastasis, and larger tumor size generally indicate a less favorable prognosis. Endocrine testing, imaging, and histological evidence are necessary to accurately diagnose PNETs. A 4-pronged aggressive treatment approach consisting of surgery, locoregional therapy, systemic therapy, and complication control has become popular in academic centers around the world. The optimal application of the multiple systemic therapeutic modalities is under development; efficacy, safety, availability, and cost should be considered when treating a specific patient. The clinical presentation, diagnosis, and treatment of specific types of PNETs and familial PNET syndromes, including the novel Mahvash disease, are summarized.

Management of gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Mainly due to better diagnostics and awareness of this tumor, the observed incidence has increased more than tenfold over the last 30 years. Small (<15-20 mm) localized type I and II lesions that are slowly proliferating (Ki67<2%) can usually be managed conservatively with endoscopic surveillance. Reducing hypergastrinemia by surgical removal of an underlying gastrinoma is important in inhibiting growth and induce reduction of type II lesions, while the specific gastrin receptor antagonist YF476 or gastrin antibodies may become useful for both type I and II lesions. Infiltrating and metastasized tumors and type III lesions require a more aggressive approach with surgical resection and consideration of modalities such as somatostatin analogs, cytotoxics, and peptide receptor targeted treatment.

Pancreatic neuroendocrine tumors: clinical features, diagnosis and medical treatment: advances

Pancreatic neuroendocrine tumors (pNETs) comprise with gastrointestinal carcinoids, the main groups of gastrointestinal neuroendocrine tumors (GI-NETs). Although these two groups of GI-NETs share many features including histological aspects; over-/ectopic expression of somatostatin receptors; the ability to ectopically secrete hormones/peptides/amines which can result in distinct functional syndromes; similar approaches used for tumor localization and some aspects of treatment, it is now generally agreed they should be considered separate. They differ in their pathogenesis, hormonal syndromes produced, many aspects of biological behaviour and most important, in their response to certain anti-tumour treatment (chemotherapy, molecular targeted therapies). In this chapter the clinical features of the different types of pNETs will be considered as well as aspects of their diagnosis and medical treatment of the hormone-excess state. Emphasis will be on controversial areas or recent advances. The other aspects of the management of these tumors (surgery, treatment of advanced disease, tumor localization) are not dealt with here, because they are covered in other chapters in this volume.

A randomized controlled trial of adding intravenous pantoprazole to conventional treatment for the immediate relief of dyspeptic pain

INTRODUCTION

Acute, severe dyspeptic pain is a common condition in the emergency department. Despite the traditional "GI cocktail" (GI indicates gastrointestinal), an intravenous (IV) proton pump inhibitor (PPI), a novel acid-lowering drug, has recently been used to treat this condition. The aim of this study was to evaluate the immediate effect of IV pantoprazole in addition to the conventional GI cocktail in the relief of severe dyspeptic pain.

METHODS

This double-blind, randomized, controlled study was conducted in the emergency department of an urban tertiary-care hospital from January 2011 to October 2011. Selected patients with severe dyspeptic pain were randomized to treatment with a placebo, antacid, and antispasmodic (conventional group) or IV pantoprazole, antacid, and antispasmodic (pantoprazole group). The self-reported 100-mm visual analog scale score, adverse effects, and overall satisfaction were evaluated in 15-minute intervals for 60 minutes.

RESULTS

Eighty-seven eligible cases were enrolled in the study. Forty-four and 43 patients were randomized in the conventional group and pantoprazole group, respectively. There was no difference in the mean 60-minute visual analog scale scores between the treatment groups. The rate of "responders," additional drug use, adverse effects, and patient satisfaction were similar between the groups.

CONCLUSION

Intravenous PPI provides no additional benefit over the conventional GI cocktail in the relief of acute, severe dyspeptic pain. Because of its neutral effect and higher cost, the use of IV PPI to treat such conditions should be discouraged in general clinical practice.

Pantoprazole for the treatment of peptic ulcer bleeding and prevention of rebleeding

Adding proton pump inhibitors (PPIs) to endoscopic therapy has become the mainstay of treatment for peptic ulcer bleeding, with current consensus guidelines recommending high-dose intravenous (IV) PPI therapy (IV bolus followed by continuous therapy). However, whether or not high-dose PPI therapy is more effective than low-dose PPI therapy is still debated. Furthermore, maintaining pH ≥ 4 appears to prevent mucosal bleeding in patients with acute stress ulcers; thus, stress ulcer prophylaxis with acid-suppressing therapy has been increasingly recommended in intensive care units (ICUs). This review evaluates the evidence for the efficacy of IV pantoprazole, a PPI, in preventing ulcer rebleeding after endoscopic hemostasis, and in controlling gastric pH and protecting against upper gastrointestinal (GI) bleeding in high-risk ICU patients. The review concludes that IV pantoprazole provides an effective option in the treatment of upper GI bleeding, the prevention of rebleeding, and for the prophylaxis of acute bleeding stress ulcers.

Evaluating ranitidine, pantoprazole and placebo on gastric pH in elective surgery

Background and Aim:

Concern about the grim nature of postoperative acid aspiration syndrome grew among the anesthesiologist over the years warranting the need for pre-emptive intervention. The aim of the study is to compare the effects of preoperative oral ranitidine versus pantoprazole given in regulating gastric pH in elective surgery.

Methods:

This prospective, parallel group, controlled, randomized, single-blind study was conducted at a tertiary care postgraduate teaching institute at Kolkata, involving 120 participants of either sex, aged 18-60 years of American Society of Anesthesiologists physical status I and II, who were scheduled for elective surgery under general anesthesia lasting for more than 2 h. The participants were divided into three groups. In group A (n=40) participants received placebo tablet, in group B (n=40) participants received ranitidine tablet while in group C (n=40), participants received pantoprazole tablet and their gastric pH estimated serially.

Results:

The participants in the three groups were comparable in terms of age, sex, body weight, duration of surgery and type of surgery distribution. In regard to changes in gastric pH trends, there was no statistically significant difference between serial pH values in group A (Friedman test; P>0.05) and group C participants. (P>0.05). However, the mean preoperative gastric pH values (7.140±.7652) were significantly lower than mean pH values (7.253±.7514) after 2 h postoperatively in group B participants (P<0.05).

Conclusion:

From the observations and analyses of the present study, it can be inferred that ranitidine is more effective than pantoprazole to raise the gastric pH for prevention of aspiration pneumonitis.

NANETS treatment guidelines: well-differentiated neuroendocrine tumors of the stomach and pancreas

Well-differentiated neuroendocrine tumors (NETs) of the stomach and pancreas represent 2 major subtypes of gastrointestinal NETs. Historically, there has been little consensus on the classification and management of patients with these tumor subtypes. We provide an overview of well-differentiated NETs of the stomach and pancreas and describe consensus guidelines for the treatment of patients with these malignancies.

Pancreatic islet cell carcinoma presenting with concurrent Cushing's and Zollinger-Ellison syndromes: case series and literature review

Cushing's syndrome and Zollinger-Ellison syndrome occur occasionally as a result of neuroendocrine cancers. The concurrence of the two syndromes has been considered to confer a poor clinical and therapeutic outcome. In this study, we are reviewing two patients with pancreatic islet cell carcinomas and with both Zollinger-Ellison and Cushing's syndromes, one followed up for more than 5 years, and the other still receiving therapy, 5 years since diagnosis. A literature review showed that surgery has limited utility as the majority of these patients had metastases at the time of diagnosis. Proton-pump inhibitors, ketoconazole, and somatostatin antagonists have a major role in controlling symptoms. Interferon and systemic chemotherapeutic agents play a role in the management of metastatic and fast-growing cases. Chemoembolization and bland embolization show encouraging results in controlling liver metastases. The latter was used effectively and more than once in the two patients presented herein. On the basis of recent molecular genetics studies, target therapy may be helpful, however, ongoing trials will define it's utility. As the data confers a worse prognosis versus other pancreatic neuroendocrine tumors, the relatively favorable outcome of the two patients reported herein may reflect the impact of multiple therapeutic modalities.

A clinical guide to using intravenous proton-pump inhibitors in reflux and peptic ulcers

Intravenous (IV) proton-pump inhibitors (PPIs) are potent gastric acid suppressing agents, and their use is popular in clinical practice. Both IV and oral PPIs have similarly short half-lives, and their effects on acid secretion are similar, thus their dosing and dosage intervals appear to be interchangeable. The possible exception is when sustained high pHs are required to promote clot stabilization in bleeding peptic ulcers. Continuous infusion appears to be the only form of administration that reliably achieves these high target pHs. IV PPI is indicated in the treatment of high-risk peptic ulcers, complicated gastroesophageal reflux, stress-induced ulcer prophylaxis, Zollinger-Ellison syndrome, and whenever it is impossible or impractical to give oral therapy. The widespread use of PPIs has been controversial. IV PPIs have been linked to the development of nosocomial pneumonia in the intensive care setting and to spontaneous bacterial peritonitis in cirrhotic patients. This review discusses the use of IV PPI in different clinical scenarios, its controversies, and issues of appropriate use.

Use of intravenous proton-pump inhibitors in a teaching hospital practice

OBJECTIVE

To evaluate intravenous proton-pump inhibitor (IV PPI) prescribing in a single academic teaching hospital.

METHODS

A retrospective pilot study of 107 patients in a single United States military teaching hospital was conducted over a 1-month period. Clinical data were collected and analyzed for demographic features, prior medication use, admission hemoglobin level, service prescribing the IV PPI, indication for IV PPI, IV PPI treatment duration, gastroenterology consultant use, endoscopic findings, and blood products given. Indications for use were compared with current established guidelines to determine appropriate usage.

RESULTS

A total of 683 doses of IV pantoprazole were prescribed over a 1-month period. Seventy-six patients (71%; 95% confidence interval [CI], 62-79%) who received IV PPIs did not meet the criteria for an appropriate indication for use. Ninety-nine patients in the study (93%; 95% CI, 86-96%) met criteria for an acceptable dosage given. The most common appropriate indication given was stress ulcer prophylaxis in a high-risk setting (13%; 95% CI, 8-21%) with appropriate use of this indication 45% of the time (95% CI, 29-62%). IV PPIs were appropriately prescribed most often by the medical intensive care unit (66.7%; 95% CI, 43-84%) and least often by the surgical wards services (16%; 95% CI, 7-33%). No discernable indication was given in 52% of cases (95% CI, 43-62%), and patients were not actually nil per os in 46% of these instances (95% CI, 34-59%).

CONCLUSIONS

Intravenous PPI prescribing habits in this military hospital facility are poor. A multifaceted approach including physician/pharmacist education, IV PPI ordering templates, and a consensus medical position statement from a major gastroenterological or prominent medical association may lead to more appropriate use.

Duodenal bulb mucosa with hypertrophic gastric oxyntic heterotopia in patients with zollinger ellison syndrome

Objectives. Zollinger-Ellison Syndrome (ZES) results in hypersecretion of gastric acid (via gastrinoma) leading to peptic ulcers, diarrhea, and abdominal pain. We describe the novel discovery of hypertrophic, heterotopic gastric mucosa in the proximal duodenal bulb in patients with ZES, which we hypothesize results in an increased incidence of postbulbar ulcers in patients with ZES (a mechanism previously unreported). We determined the incidence of the novel finding of duodenal gastric oxyntic hypertrophic heterotopia (GOH) in patients with ZES. Methods. Seven patients with ZES were enrolled. The diagnosis of ZES was established by hypergastrinemia, gastric acid hypersecretion, and a positive secretin test or based on biopsy specimens (evaluated via tissue staining). Basal acid output (BAO) and baseline gastrin secretion were determined by established methods. Endoscopic examinations with methylene blue staining and biopsy of the gastric and duodenal mucosa were conducted in all patients every 3–6 months for an average of 5 years. Results. The duodenal mucosa demonstrated hypertrophic GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. Biopsies from the bowel mucosa demonstrated patchy replacement of surface epithelium by gastric-type epithelium with hypertrophic oxyntic glands in the lamina propria in 5 patients. Two of the patients had no evidence of GOH in the duodenal bulb. Patients with GOH had an average serum gastrin level of 1245 pg/mL and BAO of 2.92 mEq/hr versus 724 pg/mL and 0.8 mEq/hr in patients without GOH. Conclusions. This study demonstrated the presence of duodenal mucosa with GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. The presence of hypertrophic and heterotopic gastric mucosa is proposed to result from increased gastrin levels and may contribute to the increased incidence of postbulbar ulcers in these patients.

Refractory peptic ulcer disease

Refractory PUD is a diagnostic and therapeutic challenge. Optimal management of severe or refractory PUD requires a multidisciplinary team approach, using primary care providers, gastroenterologists, and general surgeons. Medical management has become the cornerstone of therapy. Identification and eradication of H pylori infection combined with acid reduction regimens can heal ulceration and also prevent recurrence. Severe, intractable or recurrent PUD and associated complications mandates a careful and methodical evaluation and management strategy to determine the potential etiologies and necessary treatment (medical or surgical) required.

Effect of preoperative intravenous pantoprazole in elective-surgery patients: a pilot study

BACKGROUND

This study evaluated the effects of intravenous pantoprazole on gastric volume and acid output in elective-surgical patients.

METHODS

This is a multicenter, randomized, pilot study of adult patients receiving intravenous pantoprazole: 40 mg every 24 h, 40 mg every 12 h (q12h) or 80 mg q12h. The first dose was administered 1 h before general anesthesia for surgery. All gastric fluid was aspirated through a nasogastric tube 1 h before dosing and through the postoperative period. Aspirate volume was recorded; pH and H(+) concentrations were measured.

RESULT

Twenty-six patients were enrolled and 21 were evaluable. Pantoprazole was well tolerated. All regimens decreased gastric acid output and volume, and increased pH within 1 h of dosing. Effects were sustained for up to 12 h following single-dose administration.

CONCLUSIONS

Intravenous pantoprazole administered prior to anesthesia induction may be efficacious for the reduction of gastric volume and acid output, and for pulmonary aspiration prophylaxis in surgical patients.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

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.

Intermittent intravenous pantoprazole and continuous cimetidine infusion: effect on gastric pH control in critically ill patients at risk of developing stress-related mucosal disease

BACKGROUND

This study aimed to assess intermittent intravenous (IV) pantoprazole for control of gastric acid and the possible prevention of upper gastrointestinal (UGI) bleeding in intensive care units (ICU) patients.

METHODS

This was a multicenter, randomized, open-label, dose-ranging pilot study of IV pantoprazole (40 mg q24 hour; 40 mg q12 hour; 80 mg q24 hour; 80 mg q12 hour; 80 mg q8 hour) or continuously infused cimetidine (300 mg bolus; 50 mg/h) in patients at risk for UGI bleeding. The primary endpoint was percent time gastric pH >/=4.0. UGI bleeding and pneumonia were measured as secondary endpoints.

RESULTS

Two hundred two ICU patients were randomized. Gastric pH was well controlled by all treatments. Gastric pH control improved from day 1 to day 2 in all pantoprazole groups, whereas there was decreased pH control in the cimetidine group. There were no cases of protocol defined UGI bleeding in any treatment group. Adverse event frequency and pneumonia incidence were similar between pantoprazole and cimetidine treated patients.

CONCLUSIONS

This pilot study indicates that intermittent IV pantoprazole effectively controls gastric pH and may protect against UGI bleeding in high risk ICU patients without the development of tolerance.

A pilot study of efficacy and safety of continuous intravenous infusion of pantoprazole in the treatment of severe erosive esophagitis

BACKGROUND AND OBJECTIVES

Reflux esophagitis is a common disease. Erosive reflux esophagitis is a more advanced stage of reflux esophagitis. Although death from reflux disease is uncommon, significant morbidity and mortality from complications, such as esophageal ulcer, stricture, and cancer, are not uncommon. Proton pump inhibitors are the popular medication for reflux esophagitis. The objective of this study was to determine the efficacy and safety of continuous intravenous infusion of pantoprazole in the treatment of severe erosive esophagitis.

METHODS

From February 2005 to November 2006, all patients with grade 4 erosive reflux esophagitis were screened for the study. Eligible patients were randomized into two groups. Each patient in the study group received intravenous pantoprazole 80 mg loading dose over 5 min, followed by 8 mg/h intravenous infusion for 72 h, then 40 mg orally once a day for 4 days. Each patient in the control group received 40 mg pantoprazole intravenously once a day for 72 h, then orally once a day for 4 days. A second endoscopic gastrointestinal examination (EGD) was performed on treatment days 6-8 (+/-1 day if day 7 was on a weekend) to document any healing of esophagitis in either the study or the control group.

RESULTS

In the study group, severe erosive esophagitis healed completely in three patients and significantly in the other three by the time of the second endoscopy. In the control group, severe erosive esophagitis healed partially in five patients, and no improvement was seen at all in one patient by the time of second endoscopy. The difference in the intervention between those two groups was statistically different (P = 0.015). There were no significant complications in either group.

CONCLUSIONS

Severe erosive esophagitis can be completely healed in a few days if pantoprazole is given intravenously and continuously for 72 h. It is safe to give pantoprazole intravenously and continuously for treatment of severe erosive esophagitis.

Diagnosis and treatment of gastrinoma in the era of proton pump inhibitors

The Zollinger-Ellison syndrome is characterized pathophysiologically by a significant hypergastrinemia derived from a gastrin-secreting neuroendocrine tumor with a primary location in the pancreas or duodenum. Chronic hypergastrinemia in turn triggers gastric acid hypersecretion yielding in chronic or recurrent or refractory peptic ulcer disease and/or chronic diarrhea. One half of patients with ZES will have distant metastases in the liver by the time the diagnosis is established and one half of all patients with ZES will experience chronic diarrhea as chief complaint rather than peptic ulcer-related symptoms and signs. Gastrinomas have been reported to either manifest sporadically or to occur in conjunction with the genetic background of the MEN-I syndrome. Diagnosis is based on the patients history which is typically characterized by recurrent episodes of peptic ulcer disease or by severe reflux esophagitis and/or diarrhea or by acid-related symptoms which fail to respond to standard treatment regimens. Upper gastrointestinal tract endoscopy will provide evidence for peptic ulcer disease in anatomical regions located aborally the duodenal bulb within the descending part of the duodenum or even farther distally within the jejunum. Peptic ulcers frequently occur in groups indicating some substantial acid hypersecretion. A gastric pH > 2 is mutually exclusive for ZES. Increased serum gastrin levels confirm the diagnosis biochemically. Gastrin secretion can be determined in the basal state or following stimulation with secretin or calcium. High sensitivity and specificity for the diagnosis of ZES is provided by determining the ratio of basal versus pentagastrin-stimulated gastric acid secretion: The ratio of BAO / MAO > 0.6 is highly specific for gastrinoma. To localize the gastrin-secreting tumor computer-assisted tomography, endoscopic ultrasound, and somatostatin receptor scintigraphy provide useful help but most recently, endoscopic ultrasound with high resolution transducers appear to improve preoperative site localization. If modern imaging techniques fail to elucidate the site of the tumor, intraoperative diaphany may help to detect gastrinomas within the duodenal wall. Definitive treatment will only be achieved by total surgical resection of the gastrin-producing tumor in the pancreas or duodenum including dissection of the regional lymph nodes. Control of symptoms will have to be achieved by administration of highly potent proton pump inhibitors in up to 2-3-fold increased standard doses to inhibit gastric acid hypersecretion. Elevation of gastric pH > 4 will be the therapeutic target to protect the mucosa of the upper gastrointestinal tract. Basal acid output should be reduced to less than 10 mEq H(+) per hour which requires administration of highly potent proton pump inhibitors with a recommended starting dose of 60 mg omeprazole equivalents per day.

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.

Management of sporadic and multiple endocrine neoplasia type 1 gastrinomas

BACKGROUND

Gastrinomas are functional endocrine duodenopancreatic tumours and are responsible for Zollinger-Ellison syndrome (ZES). Clinical presentation, localization techniques and operative management were reviewed.

METHODS

An electronic search of the Medline database was undertaken for articles published in English between January 1987 and May 2007. This timeframe was chosen because of the fundamental changes in operative strategy, antisecretory therapy and localization techniques during this period.

RESULTS AND CONCLUSION

Most gastrinomas are located in the 'gastrinoma triangle', comprising the head of the pancreas, and the first and second parts of the duodenum. Some 20 per cent of gastrinomas occur in association with multiple endocrine neoplasia type 1 (MEN1) and 50-60 per cent of tumours are malignant at the time of diagnosis. Biochemical evidence justifies operation of which duodenotomy is an essential part. Only complete tumour resection allows 5- and 10-year survival rates of 90 per cent. Pylorus-preserving pancreaticoduodenectomy may be the procedure of choice for MEN1-ZES.

Intravenous pantoprazole as initial treatment in patients with gastroesophageal reflux disease and a history of erosive esophagitis: a randomized clinical trial

We sought to evaluate safety and efficacy of IV pantoprazole when used as initial therapy in patients with gastroesophageal reflux disease (GERD) and a history of erosive esophagitis (EE) in a double-blind, placebo-controlled, randomized, parallel-group study. Patients were randomized to 7 days of once-daily IV or oral pantoprazole (40 mg) or placebo. Efficacy variables included maximal acid output, basal acid output, and changes from baseline in frequency/severity of GERD symptoms, and frequency of antacid usage. Seventy-eight patients were randomized (n=26/27/25 [IV/oral/placebo]). Mean maximal acid output was 8.4, 6.3, and 20.9 mEq/h for IV or oral pantoprazole, and placebo, respectively. For pantoprazole versus placebo, maximal and basal acid output were significantly lower (P<.001) and there was a numerical trend toward improved GERD and antacid usage. Both treatments were well tolerated. In conclusion, IV/oral pantoprazole were similarly effective in suppressing basal and pentagastrin-stimulated gastric acid secretion in GERD patients with a history of EE.

The role of proton pump inhibitors in the treatment of Zollinger-Ellison syndrome

Zollinger-Ellison syndrome is characterised by refractory peptic ulcer disease, diarrhoea and gastric acid hypersecretion associated with a gastrin-secreting tumour. The incidence is unknown, but, in the US, the frequency is 0.1-3.0 million people. Zollinger-Ellison syndrome is associated with multiple endocrine neoplasia type 1 in 25-35% of the cases. The diagnosis of Zollinger-Ellison syndrome is suggested when plasma gastrin is > 1000 pg/ml and the basal acid output is > 15 mEq/h or when associated with a pH < 2. The treatment is focused on controlling gastric acid hypersecretion and localisation of the tumour and its metastases. Proton pump inhibitors are the most effective antisecretory drugs and can be administered at high dosages. This review focuses on the role of the proton pump inhibitors in the management of gastric acid hypersecretion in Zollinger-Ellison syndrome.

Severe and refractory peptic ulcer disease: the diagnostic dilemma: case report and comprehensive review

The recognition of Helicobacter pylori infection as a cause of peptic ulcer disease, medical regimens to eradicate the organism, and the widespread use of proton pump inhibition to suppress gastric acid secretion have revolutionized the management of peptic ulcer disease. As a result, successful medical management of peptic ulcer disease has largely supplanted the need for gastric surgery by general surgeons. Surgery is reserved for complications of the disease, refractory disease, or rare causes of ulcer disease such as gastrinoma and Zollinger-Ellison syndrome. In this report, we describe a case of intractable peptic ulcer disease that progressed to gastric outlet obstruction despite maximal medical therapy. We review the diagnostic studies utilized to evaluate the potential etiologies of peptic ulcer disease and the difficulty in diagnosing gastrinoma and Zollinger-Ellison in the setting of potent medical acid suppression therapy.

Proton pump inhibitor formulary considerations in the acutely ill. Part 2: Clinical efficacy, safety, and economics

OBJECTIVE

To review, using an evidence-based approach, the clinical efficacy, safety, and cost-effectiveness of proton pump inhibitors (PPIs) for treatment of common acid peptic disorders in the acutely ill and provide clinicians with guidance when making hospital formulary decisions with this class of agents.

DATA SOURCES

MEDLINE (1966-May 2005) and the Cochrane Library databases were searched using the key words proton pump inhibitor, acid suppression, peptic ulcer disease, gastrointestinal bleeding, stress ulcer prophylaxis, critical care, safety, and cost-effectiveness. Bibliographies of cited references were reviewed, and a manual search of abstracts from recent gastroenterology, critical care, and surgery scientific meetings was completed.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated, and all information deemed relevant was included for this review.

DATA SYNTHESIS

PPIs have become a mainstay for acute acid suppression in hospitalized patients. Various commercially available PPI products are available either enterally or parenterally for administration to patients unable to swallow a tablet or capsule. The results of studies comparing the clinical efficacy of different PPI dosage forms and routes of administration, safety considerations, and cost-effectiveness analyses are among the factors to consider when making formulary decisions for this class of drugs.

CONCLUSIONS

While the introduction of new PPI products has expanded the therapeutic options for acid suppression in acutely ill patients, a number of unresolved questions remain surrounding the interchangeability of these products, the clinical significance of one PPI formulation over the other, and how oral/enteral therapy should be used as step-down therapy after parenteral therapy.

Duodenal neuroendocrine tumors: Classification, functional syndromes, diagnosis and medical treatment

Duodenal neuroendocrine tumors (NETs) comprise 2-3% of all GI endocrine tumors and are increasing in frequency. These include gastrinomas, somatostatinomas, nonfunctional NETs, gangliocytic paragangliomas, and poorly differentiated NE carcinomas. Although, the majority are nonfunctional, these tumors are a frequent cause of Zollinger-Ellison syndrome and can cause other clinical hormonal syndromes (carcinoid, Cushing's, etc.). In this chapter, their epidemiology, clinical aspects, localization, diagnosis and medical treatment are reviewed including the latest advances in each area.

Treatment of Zollinger-Ellison Syndrome

In this article, we have reviewed the main therapeutic measures for the treatment of Zollinger-Ellison syndrome (ZES). Review of the literature was based on computer searches (Pub-Med, Index Medicus) and personal experiences. We have evaluated all the measures now available for treating patients with sporadic gastrinomas or gastrinomas associated with Multiple Endocrine Neoplasia Type 1, (MEN 1) including medical therapy such as antisecretory drugs and somatostatin analogs (SST), chemotherapy and chemoembolization, and surgical procedures. In ZES patients, the best therapeutic procedure is surgery which, if radical, can be curative. Medical treatment can be the best palliative therapy and should be used, when possible, in association with surgery, in a multimodal therapeutic approach.

Proton pump inhibitors for acid suppression in the intensive care unit: Formulary considerations

PURPOSE

The rationale for limiting the proton pump inhibitor (PPI) products included in an institutional formulary, factors to consider when making formulary decisions about PPI products, the results and limitations of cost-effectiveness analyses of PPI therapy in critically ill patients, the role of clinical practice guidelines in improving PPI use in the intensive care setting, and how these guidelines can be developed are discussed.

SUMMARY

Therapeutic interchange may make it possible to limit the number of PPI products included in the formulary and reduce costs without compromising the efficacy or safety of drug therapy. The results of studies comparing the pharmacokinetics, pharmacodynamics, and efficacy of different PPI dosage forms and routes of administration; practical considerations; safety; and costs are among the factors to consider when making formulary decisions. Some of the newer oral PPI products offer advantages over older ones in improved palatability and ease of preparation, storage, and administration. The cost-effectiveness of intravenous (i.v.) PPIs for preventing the recurrence of peptic ulcer bleeding has been demonstrated, but the cost-effectiveness of oral therapy for this indication and both oral and i.v. therapy for preventing stress-related mucosal bleeding has not been well established.

CONCLUSION

Intravenous PPIs are cost-effective for patients at risk for the recurrence of peptic ulcer bleeding. The introduction of new oral PPI products that can be administered as a suspension has expanded the therapeutic options for critically ill patients. The use of clinical practice guidelines can optimize the use of PPIs in the intensive care setting.