Recklinghausen's disease with digestive localizations associated with gastric acid hypersecretion suggesting Zollinger-Ellison syndrome

We report the case of a 49 year old male patient who had Recklinghausen's disease associated with hyperchlorhydria. The principal features of Recklinghausen's disease were cutaneous localizations and countless digestive tumors, found mainly on the small bowel. The ultrastructural aspect of these tumors was neurinoma or schwannoma. Basal acid gastric hypersecretion and a positive secretin test were highly suggestive of a Zollinger-Ellison syndrome. Gastrinoma was not found at laparotomy even though a gastrin gradient had been demonstrated by pancreatic venous sampling. In a patient with Recklinghausen's disease, neuroendocrine tumors (APUDomas) should be looked for systematically.     

Physiologic responses to gastric acid hypersecretion in Zollinger-Ellison syndrome

Summary Two patients with gastric acid hypersecretion and intact stomachs had diarrhea with steatorrhea. In 1 patient continuous outpouring of large volumes of alkaline juice into the duodenum, combined with the buffering capacity of food, resulted in normal or near normal pH levels in the upper small intestine for at least 90 min. after a meal. The tryptic activities in intestinal aspirates after the meal were essentially normal. Watery diarrhea was controlled when an anticholinergic drug was given both night and day, but steatorrhea was not reduced. In the other patient the alkaline secretions of the upper intestine were inadequate to neutralize the gastric acid output. The mechanisms by which acid secreted by the stomach is neutralized in the upper small bowel and the mechanisms of diarrhea are discussed.Supported by Grants FR-42 from the Division of Research Facilities and Resources and AM-07120 from the National Institute for Arthritis and Metabolism, U. S. Public Health Service.We wish to thank Dr. F. Avery Jones for allowing us to publish Case 2, and Professor R. A. Gregory for examining the tumors.     

Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome

Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome is increasingly required; however, existing methods of determining the required dose are cumbersome and not applicable in all centers. A previous study suggested that the required parenteral dose of histamine H₂-receptor antagonists correlated with the previous oral dose. In the present study, in 31 patients with Zollinger-Ellison syndrome we evaluated the hypothesis that an effective parenteral histamine H₂-receptor antagonist dose could be predicted from the previous oral dose. Twenty-three patients were taking oral ranitidine (mean 1.3 g/day), six patients famotidine (152 mg/day), and two patients cimetidine (1.8 g/day). Each patient was treated with a continuous intravenous infusion of the equivalent dose of ranitidine (mean dose 1 mg/kg/hr with 35% requiring 0.5 mg/kg/hr, 49% 1 mg/kg/hr, 3% 1.5 mg/kg/hr, 10% 2 mg/kg/hr, and 3% 2.5 mg/kg/hr. This dose of ranitidine acutely controlled acid secretion (<10 meq/hr) in all patients. To evaluate long-term efficacy and safety, 20 patients were maintained on this dose through the peri-and postoperative periods. Mean duration was 7.1 days with 25% treated 3–5 days, 40% 6–8 days, 30% 8–10 days, and 5%>10 days. The predicted dose continued to control acid secretion in 95% of patients with one patient requiring one dose adjustment. No biochemical, clinical, or hematological toxicity was seen, although ranitidine was stopped in one patient because of skin rash. These results demonstrate that the parenteral dose of ranitidine required to control acid secretion in patients with Zollinger-Ellison syndrome can be predicted from the oral dose. This predicted dose will be acutely effective in all patients in reducing acid secretion to <10 meq/hr, the established level of control, will remain effective in 95% of patients for up to 11 days, and is safe. By utilizing the oral dose to predict the intravenous dose, repeated dose titrations will be avoided and thus this method should be generally useful in all settings.     

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

BACKGROUND & AIMS: Parenteral control of gastric acid hypersecretion in conditions such as Zollinger-Ellison syndrome (ZES) or idiopathic gastric acid hypersecretion is necessary perioperatively or when oral medications cannot be taken for other reasons (e.g., during chemotherapy, acute upper gastrointestinal bleeding, or in intensive care unit settings). METHODS: We evaluated the efficacy and safety of 15-minute infusions of the proton pump inhibitor pantoprazole (80-120 mg every 8-12 hours) in controlling acid output for up to 7 days. Effective control was defined as acid output >10 milliequivalents per hour (mEq/h) (<5 mEq/h in patients with prior acid-reducing surgery) for 24 hours. RESULTS: The 21 patients enrolled had a mean age of 51.9 years (range, 29-75) and a mean disease duration of 8.1 years (range, <0.5-21); 13 were male, 7 had multiple endocrine neoplasia syndrome type I, 4 had undergone acid-reducing surgery, 2 had received chemotherapy, and 13 had undergone gastrinoma resections without cure. Basal acid output (mean +/- SD) was 40.2 +/- 27.9 mEq/h (range, 11.2-117.9). In all patients, acid output was controlled within the first hour (mean onset of effective control, 41 minutes) after an initial 80-mg intravenous pantoprazole dose. Pantoprazole, 80 mg every 12 hours, was effective in 17 of 21 patients (81%) for up to 7 days. Four patients required upward dose titration, 2 required 120 mg pantoprazole every 12 hours, and 2 required 80 mg every 8 hours. At study end, acid output remained controlled for 6 hours beyond the next expected dose in 71% of patients (n = 15); mean acid output increased to 4.0 mEq/h (range, 0-9.7). No serious or unexpected adverse events were observed. CONCLUSIONS: Intravenous pantoprazole, 160-240 mg/day administered in divided doses by 15-minute infusion, rapidly and effectively controlled acid output within 1 hour and maintained control for up to 7 days in all ZES patients.     

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.     

Recent advances in the management of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome

Several histamine H2 receptor antagonists and the H+,K(+)-ATPase inhibitor, omeprazole, have been shown to be capable of controlling gastric acid secretion safely and effectively in patients with Zollinger-Ellison syndrome. The relative merits of these agents are discussed, and their use in the acute and long-term control of acid hypersecretion and in special circumstances that require particular care are described. The surgical approaches to the control of acid secretion are described, and the current place of surgery in the management of acid hypersecretion is discussed.     

Diagnosis of Zollinger-Ellison syndrome: Increasingly difficult

In the present paper the increasing difficulty of diagnosis of Zollinger-Ellison syndrome (ZES) due to issues raised in two recent papers is discussed. These issues involve the difficulty and need to withdraw patients suspected of ZES from treatment with Proton Pump Inhibitors (omeprazole, esomeprazole, lansoprazole, rabeprazole, pantoprazole) and the unreliability of many gastrin radioimmunoassays. The clinical context of each of these important issues is reviewed and the conclusions in these articles commented from the perspective of clinical management.     

Idiopathic gastric acid hypersecretion presenting as a diarrheal disorder and mimicking both Zollinger-Ellison syndrome and Crohn's disease

Many gastric acid hypersecretory states (basal acid output of greater than 15.0 mEq/h) exist for which the etiology is known, such as Zollinger-Ellison syndrome, systemic mastocytosis, antral exclusion, antral predominant Helicobacter pylori gastritis (antral G cell hyperplasia), chronic gastric outlet obstruction, short gut syndrome and basophilic leukemias. However, many hypersecretory patients have no identified etiology for their acid hypersecretion and are designated as idiopathic gastric acid hypersecretors with a basal acid output of greater than 10 mEq/h and a normal serum gastrin level. Because of the gastric acid hypersecretion these patients also commonly have an increased frequency of stools. Idiopathic gastric acid hypersecretion represents a known cause of gastric acid hypersecretion that is far more common than Zollinger-Ellison syndrome and it has a markedly different treatment regimen and natural history. We report a case of a patient with idiopathic gastric acid hypersecretion previously misdiagnosed as having Crohn's disease because of a presenting complaint of diarrhea and mimicking Zollinger-Ellison syndrome because her fasting serum gastrin level was elevated when incorrectly measured in the presence of antisecretory treatment.     

Diagnosis and treatment of Zollinger-Ellison syndrome

A diagnostic and therapeutic strategy for the management of patients with Zollinger-Ellison syndrome has been developed, based on the review of a large personal experience and the most recent literature. The mainstay of a modern ZES management is the eradication of tumoral processes whenever feasible. Diagnosis is centred upon gastric acid and gastrin secretion measurements both in basal conditions and on secretin stimulation. Recognition of other endocrine involvement and familial inheritance is of the utmost importance in distinguishing sporadic ZES patients from those who have the condition known as multiple endocrine neoplasia type I. Blood calcium and phosphorus levels, parathyroid hormone concentration, combined if necessary with urinary cyclic AMP excretion measurement, should be performed routinely once ZES diagnosis is established or highly suspected. Localization of the tumour is the next essential step, and this has been considerably facilitated by the recent development in imaging techniques: it involves computerized axial tomography and selective abdominal angiography, a combination of which allows tumour detection in 60-70% of sporadic gastrinoma patients, with a maximal sensitivity for well-developed hepatic metastases. In sporadic ZES exploratory laparotomy is legitimate when preoperative localization of the tumour has failed; this laparotomy will allow further detection and then eradication of gastrinomas in a significant number of patients. Control of gastric acid secretion is mandatory throughout the work-up period; modern antisecretory agents are efficacious in most cases; total gastrectomy, when control of acid hypersecretion has failed, is now exceptional. Eradication of the tumour should be attempted in cases of sporadic ZES in the absence of recognizable liver involvement. The chance of a definite cure provided by surgery when performed by an experienced surgeon varies from 20% to 60% in pancreatic and ectopic gastrinomas respectively. In ZES patients with MEN I, exploratory laparotomy is seldom indicated (other than for symptomatic associated endocrine secretion), as the chance of a definite cure by surgery is very rare. Parathyroid surgery is often indicated and should take place before any form of abdominal surgery. In cases of hepatic metastases, chemotherapy with streptozocin and fluorouracil is indicated and soon, perhaps, chemo-embolization.     

Diagnosis and management of Zollinger-Ellison syndrome

With the recent widespread availability of gastrin radioimmunoassays, the development of increasingly effective medical therapy for gastric hypersecretion, and improved methods to localize gastrinomas in patients with Zollinger-Ellison syndrome, the diagnosis, treatment of the gastric acid hypersecretion, and approach to the tumor have changed significantly. Recent advances in each of these areas and the current management of a patient with Zollinger-Ellison syndrome are reviewed.     

Maintenance oral pantoprazole therapy is effective for patients with Zollinger-Ellison syndrome and idiopathic hypersecretion

OBJECTIVE: Maintenance proton pump inhibitor (PPI) therapy is effective for gastric acid hypersecretory states, although data with pantoprazole are limited. The aim of this study was to evaluate the safety and efficacy of long term p.o. pantoprazole in individuals with hypersecretion. METHODS: All subjects had Zollinger-Ellison syndrome or idiopathic hypersecretion. Baseline acid output was measured in the presence of prior maintenance antisecretory therapy before pantoprazole exposure. The starting dose was 40 mg b.i.d. in most cases, and the dose was adjusted to document control within the first 2 wk of therapy. The maximal allowable dose was 240 mg daily. Acid output was measured on day 28 and then quarterly from month 3. The primary efficacy endpoint was documented control of acid secretion at 6 months, i.e., acid output in the last 1 h before the next dose of therapy of <10 mEq/h (<5 mEq/h in subjects with prior acid-reducing surgery). RESULTS: A total of 26 subjects had Zollinger-Ellison syndrome (six with multiple endocrine neoplasia syndrome type 1) and nine had idiopathic hypersecretion. Pre-enrollment therapy included omeprazole in 27 subjects and lansoprazole in eight, and 82.4% of subjects were controlled on their prior regimens. With upward dose titration, acid output was controlled in all subjects by day 10 and in all but two (6%) at the 6-month time point. Median acid secretion on therapy at 6 months was <2 mEq/h (mean 2.2 mEq/h; range 0-10.5 mEq/h) at a dose of 40 mg b.i.d. for 24 subjects, 80 mg b.i.d. for seven subjects, and 120 mg b.i.d. for two subjects. During the course of the study, five subjects required doses of 240 mg daily. Pantoprazole was generally well tolerated. No cases of anterior optic ischemic neuropathy occurred. Five subjects died during follow-up, all because of events unrelated to the study drug. CONCLUSIONS: Maintenance p.o. pantoprazole therapy at a dose of 80-240 mg/day in divided doses was both effective and generally well tolerated for patients with Zollinger-Ellison syndrome and idiopathic hypersecretion.     

Replacement of oral proton pump inhibitors with intravenous pantoprazole to effectively control gastric acid hypersecretion in patients with Zollinger-Ellison syndrome

OBJECTIVES: In patients with Zollinger-Ellison syndrome (ZES) or other conditions requiring oral doses of proton pump inhibitors, it frequently becomes necessary to use parenterally administered gastric acid inhibitors. However, i.v. histamine-2 receptor antagonists are not effective at usual doses and lose their effectiveness because of tachyphlaxis. With the approval in the United States of i.v. pantoprazole, a substituted benzimidazole available in i.v. formulation, it will become possible to acutely manage gastric acid secretion in the acute care setting of a hospital. This study was developed to monitor the safety and establish the efficacy of i.v. pantoprazole as an alternative to oral proton pump inhibitors for the control of gastric acid hypersecretion in patients with ZES. METHODS: The efficacy of replacing oral PPI therapy with i.v. pantoprazole was evaluated in 14 ZES patients. After study enrollment, patients taking their current doses of oral PPI (omeprazole or lansoprazole) were switched to pantoprazole i.v. for 6 days during an 8-day inpatient period in the clinical research center. Effective control was defined as an acid output (AO) of < 10 mEq/h (< 5 mEq/h in patients with prior gastric acid-reducing surgery). RESULTS: The mean age of the 14 patients enrolled in the study was 52.4 yr (range = 38-67). Mean basal AO was 0.55 +/- 0.32 mEq/h and mean fasting gastrin was 1089 pg/ml (range = 36-3720). Four patients were also diagnosed with the multiple endocrine neoplasia type I syndrome, nine were male, and two had previously undergone acid-reducing surgery. Before study enrollment, gastric acid hypersecretion was controlled in nine of 14 patients with omeprazole (20-200 mg daily) and five of 14 with lansoprazole (30-210 mg daily). In the oral phase of the study all patients had adequate control of gastric acid secretion, with a mean AO of 0.55 +/- 0.32 mEq/h (mean +/- SEM). Thereafter, 80 mg of i.v. pantoprazole was administered b.i.d. for 7 days by a brief (15 min) infusion and the dose was titrated upward to a predetermined maximum of 240 mg/24 h to control AO. A dose of 80 mg b.i.d. of i.v. pantoprazole controlled AO in 13 of 14 of the patients (93%) for the duration of the study (p > 0.05 compared to baseline values for all timepoints). One sporadic ZES patient (oral control value = 0.65 mEq/h on 100 mg of omeprazole b.i.d. p.o.) was not controlled with 80 mg of i.v. pantoprazole b.i.d. and dosage was titrated upward to 120 mg b.i.d. after day 2. CONCLUSIONS: There were no serious adverse events observed. Intravenous pantoprazole provides gastric acid secretory control that is equivalent to the acid suppression observed with oral proton pump inhibitors. Most ZES patients (93%) maintained effective control of AO previously established with oral PPIs when switched to 80 mg of i.v. pantoprazole b.i.d.; however, for difficult-to-control patients, doses > 80 mg b.i.d. may be required.     

Treatment of gastric acid hypersecretion in the Zollinger-Ellison syndrome with a thioamide derivative (40749 RP). Comparison with ranitidine

The efficacy of a new gastric antisecretory drug, 40749 RP, was studied in five cases of Zollinger-Ellison syndrome. Daily oral dosage was 2 mg/kg bw b.d. Clinical results and tolerance were excellent in all five cases (follow-up 1 to 16 months). In two cases, chronic duodenitis disappeared with 40749 RP only. Antisecretory activity was evaluated on basal acid output and 24 h pH profile. During 24 h period, the mean number of hours at or below pH 1.5, 2 and 3 obtained with 40749 RP in the five cases was 5, 9 and 12 h versus 13, 14 and 19 h with ranitidine. In all cases, basal acid output measured during one hour before fractional intake of 40749 RP was below 7 mmol/h during the first month of treatment. Clinical and biological results obtained with 40749 RP are similar to those obtained with omeprazole.     

Diagnosis of the Zollinger-Ellison syndrome. I: Significance of anamnestic,clinical and laboratory examinations

The authors describe the diagnostic algorithm of Zollinger-Ellison's syndrome which proved useful in the diagnosis of 73 patients with a confirmed diagnosis. They evaluate the diagnostic validity of anamnestic and clinical data, of different examination methods and compare them with experience assembled abroad. For the diagnosis of sporadic gastrinomas the onset of the disease after the age of 40 years is important, the development of serious peptic complications (haemorrhage F-70%, M-59%, perforation M-54%, F-47%) and the presence of watery diarrhoea (41%). As to laboratory parameters they rely on high BAO values (96% > 15 mmol H+/hour and 100% > 5 mmol H+ after gastric resection. Less important is the examination of basal serum gastrin (almost 30% patients have normal or liminal values of BSG--empirically set at 100-150 pg. ml-1). The authors draw attention to the fact that patients with ZES after gastric resections may have BSG values lower than 100 pg/ml (12%). A positive secretin test has a higher validity (rise of SG by 150-200 pg. ml-1 above basal values) positive in 82.2% patients, liminally positive in 11% and negative in 6.3% patients. An even higher diagnostic value was possessed by a BAO/MAO index higher than 0.6 which was positive in 93.4% patients. At present it is not used as pentagastrin is not available. Every year they diagnose 4-6 new cases of ZES which with regard to the number of inhabitants (5 million) places Slovakia along with Denmark and Sweden among the countries with the highest detection rate (0.8-1.2 ZES cases/1 million per year).     

Omeprazole: effective, convenient therapy for Zollinger-Ellison syndrome

The acute and long-term effects of omeprazole on gastric acid secretion were examined in 11 patients with Zollinger-Ellison syndrome. Basal gastric acid secretion was inhibited by 50% 3 h after a single 60-mg dose of omeprazole and 78% 4 h after administration of omeprazole. Patients were treated with a single daily dose of omeprazole, and the dose requirement was defined as the lowest dose of omeprazole that would reduce gastric acid secretion to less than 10 mEq/h during the last hour before the next dose. The mean daily dose requirement was 70 mg (range 20-160 mg). Ten of the 11 patients were given omeprazole once a day and 1 patient required omeprazole every 12 h. When omeprazole was discontinued after several months of therapy, mean basal gastric acid secretion was inhibited by greater than 50% 48 h after administration of omeprazole. Omeprazole continued to inhibit gastric acid secretion during 1-9 mo of therapy and patients remained free of toxicity or side effects related to omeprazole. Omeprazole is a highly effective inhibitor of gastric acid secretion in patients with Zollinger-Ellison syndrome. Because of its potency and long duration of action, omeprazole offers an advance in convenient medical therapy for Zollinger-Ellison syndrome compared with the histamine H2-receptor antagonists.