Current management of Zollinger-Ellison syndrome

Famotidine does not affect human sperm fertility characteristics (motility, viability and DNA integrity) in vitro

Famotidine, a histamine-2 receptor antagonist, is commonly used to relieve the acid-related gastrointestinal diseases; however, its effect on human sperm parameters, and hence on sperm function, is still undetermined. Here, we intended to measure human sperm motility, viability, and DNA integrity of ejaculated human sperm in the presence of famotidine at 0, 0.1, 1 and 10 mM concentrations in vitro. Forty-nine semen samples of normal count, motility, and morphology were included in this study. Sperm motility was assessed using Makler counting chamber and a phase contrast optics (200× magnification), whereas sperm viability was assessed using eosin-nigrosin staining procedure. The effect of famotidine on sperm DNA integrity was measured using flow cytometry. Famotidine at 0.1, 1 or 10 mM had insignificant effect on human sperm motility (progressive, p = .9594; and total, p = .8420), sperm viability (p = .6471), and content of DNA breaks in sperm (p > .05) compared with the control. In conclusion, famotidine at 0.1, 1 or 10 mM did not alter human sperm motility, viability or DNA integrity in vitro. Although, these findings indicate safety of famotidine in human sperm, further in vivo studies are required to establish the drug's safety.

Role of acid suppressants in patients with Zollinger-Ellison syndrome

Virtually all symptoms in patients with Zollinger-Ellison syndrome are due to acid hypersecretion, thus the control of acid secretion is the first and most important step in the management of patients with this syndrome. Antisecretory medication is prescribed as soon as the diagnosis of Zollinger-Ellison syndrome is made, as patients may bleed or perforate with little warning. Acid output is reduced to less than 10 mmol/h to heal mucosal lesions, but in patients with a Billroth I or II gastrectomy and those with severe oesophagitis and stricture formation, acid output is reduced to less than 5 or less than 1 mmol/h. Acid output and not symptomatic response is a reliable guide of the adequacy of therapy. In sufficient doses, all H2-receptor antagonists are useful; however, side effects associated with cimetidine therapy limit its use. The ratio of potencies of cimetidine:ranitidine:famotidine is 1:4:32. Ranitidine given as a 50-mg intravenous bolus, followed by a continuous infusion of 0.5 mg.kg/h, controls acid hypersecretion acutely in patients with Zollinger-Ellison syndrome. Acid output is checked after 4 h, and the dose increased until acid output is less than 10 mmol/h. In 70% of patients with Zollinger-Ellison syndrome, 1 mg.kg/h reduces acid output to less than 10 mmol/h; however, doses up to 4 mg.kg/h have been used. When patients are switched to oral ranitidine, a useful dosage conversion is to administer 1.5 times the total daily intravenous dose in four equal doses every 6 h. Four doses of oral drug are given before the infusion is stopped. Six hours after the first/last oral dose, acid output is checked. In our patients, the mean dose of ranitidine was 2100 mg/day (range, 450-9200 mg/day). No serious toxicity was observed. Omeprazole, which has a long duration of action and is a potent inhibitor of gastric acid secretion, has simplified management. Once-daily dosing is sufficient in most patients, and a reasonable starting dose is 60 mg daily. The dose may be increased to 120 mg once daily; if this dosage fails to control acid secretion, 60 mg is administered every 12 h. In our studies, the median dose was 90 mg/day (range, 20-120 mg/day). Omeprazole was more effective than H2-receptor antagonists in providing symptom relief and mucosal healing and did not cause significant toxicity. In particular, no gastric carcinoid tumours developed during four years of use. Omeprazole is, therefore, the treatment of choice for control of acid secretion in patients with Zollinger-Ellison syndrome.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

Management of patients with Zollinger-Ellison syndrome

Zollinger-Ellison syndrome (ZES) is caused by gastrin-secreting tumors called gastrinomas. Patients commonly present with peptic ulcer disease and may have recurrent, multiple, and atypically located ulcers, e.g. in the jejunum. Alternatively, severe diarrhea may be the only presenting symptom. Patients with multiple endocrine neoplasia Type I (MEN-I) and ZES become symptomatic at an earlier age than patients with sporadic ZES. Patients with ZES have elevated fasting serum gastrin concentrations (> 100 pg/ml) and basal gastric acid hypersecretion (> 15 mEq/h). The secretin stimulation test is the best test to distinguish ZES from other conditions resulting in elevated gastrin levels. Gastric acid hypersecretion can be controlled in virtually all patients with H2-receptor antagonists or omeprazole, thus rendering total gastrectomy unnecessary. Computed tomography (CT), magnetic resonance imaging (MRI), radionuclide octreotide scanning, endoscopic ultrasound, and the selective arterial secretin injection test are the recommended imaging studies for localization of gastrinoma; nevertheless, 50% of gastrinomas are not evident on preoperative imaging studies. All patients with sporadic gastrinoma who do not have unresectable metastatic disease should undergo exploratory laparotomy for potential curative resection. With increased awareness of duodenal tumors, gastrinoma can be found in 80-90% of patients. Surgery may be the most effective treatment for metastatic gastrinoma if most or all of the tumor can be resected. The management of patients with MEN-I and ZES remains controversial. Some clinicians advocate an aggressive surgical approach, whereas others have had little success in rendering patients eugastrinemic.

Omeprazole. An update of its pharmacology and therapeutic use in acid-related disorders

Omeprazole, a gastric acid pump inhibitor, dose-dependently controls gastric acid secretion: the drug has greater antisecretory activity than histamine H2-receptor antagonists. Omeprazole 20 to 40 mg/day is more effective than histamine H2-receptor antagonists in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. Available data suggest that omeprazole 10 to 40 mg/day is also more effective than ranitidine in the maintenance therapy of duodenal ulcer and reflux oesophagitis. The drug is also effective in patients with duodenal ulcer, gastric ulcer or reflux oesophagitis poorly responsive to histamine H2-receptor antagonists. The efficacy of omeprazole 20 mg/day appears to be similar to that of lansoprazole 30 mg/day in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. However, most available studies have been reported in abstract form only, and 2 of 3 studies in patients with duodenal ulcer have shown greater healing rates at 2 (but not 4) weeks with lansoprazole. Helicobacter pylori eradication decreases duodenal ulcer relapse rates and appears to be associated with improved duodenal ulcer healing rates. Evidence also suggests that H. pylori eradication is associated with reduced gastric ulcer relapse rates. Omeprazole monotherapy may suppress but does not eradicate H. pylori infection. Eradication rates with omeprazole 20 or 40 mg twice daily plus amoxicillin usually up to 2 g/day (3 g/day in a few studies) for 2 weeks appear to be similar to those of standard triple therapy (bismuth salt plus metronidazole, plus tetracycline or amoxicillin) or omeprazole plus clarithromycin, although eradication rates vary widely. Omeprazole plus amoxicillin appears to be better tolerated than triple therapy and represents a first-line treatment alternative in patients with H. pylori-associated peptic ulcer disease. Omeprazole plus amoxicillin plus metronidazole appears to be more effective than omeprazole plus amoxicillin in patients with metronidazole-sensitive H. pylori infection. Omeprazole remains a treatment of choice in patients with Zollinger-Ellison syndrome. The dosages should be adjusted according to individual response. However, relatively low dosages of 10 to 40 mg/day may be sufficient in some patients. The drug has also shown promise in the treatment of children with severe reflux oesophagitis, in patients with reflux oesophagitis and coexisting systemic sclerosis, and in the prevention of aspiration pneumonia. Evidence suggests that omeprazole is more effective than ranitidine in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage who continue to take NSAIDs, especially in patients with large gastric ulcers; however, completion of ongoing studies is required to verify this.(ABSTRACT TRUNCATED AT 400 WORDS)

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

During the last 5 years important advances have occurred in the control of gastric acid hypersecretion in Zollinger-Ellison syndrome (ZES). The increased availability of potent gastric acid antisecretory agents such as histamine H2-receptor antagonists and more recently the H+K(+)-ATPase inhibitors such as omeprazole and lansoprazole have made it possible to medically control acid secretion in all patients. Increased understanding of the variation in antisecretory drug dosage between individual patients has led to identification of criteria to ensure effective antisecretory control and to the recognition of subgroups of patients who require special monitoring. Effective regimens for parenteral antisecretory control during surgery have been established. The importance of parathyroidectomy in patients with multiple endocrine neoplasia type I with ZES and the possible usefulness of highly selective vagotomy have been investigated. We review here the new data that led to increased understanding in each of these areas from our studies and studies by others.

Prospective study of the long-term efficacy and safety of lansoprazole in patients with the Zollinger-Ellison syndrome

The long-term safety and efficacy of lansoprazole were studied in 21 patients with Zollinger-Ellison syndrome. The initial maintenance dose was determined by acid inhibition studies. In all patients lansoprazole controlled gastric acid hypersecretion and peptic symptoms in both the short and long term. Patients were treated for a mean of 31 months (range 1-43 months) with all but 4 patients followed for > 18 months. The mean initial dose was 60 mg/day, with 2 patients requiring a twice daily dose and the others a single daily dose. During long-term treatment 6 patients required an increased dosage, 5 within the first year. Long-term maintenance doses were reduced in 5 of the 6 patients in whom this was attempted. No changes in serum gastrin concentration, haematological parameters, liver function studies or other biochemical parameters occurred due to lansoprazole. No patient developed a gastric carcinoid tumour while being treated with lansoprazole. These results demonstrate that long-term treatment with lansoprazole is both safe and effective in patients with Zollinger-Ellison syndrome, and suggest that this drug will be useful in such patients. Furthermore, maintenance doses of lansoprazole, determined by the currently recommended method of acute acid titration studies in patients with Zollinger-Ellison syndrome, are too high.

Omeprazole. An updated review of its pharmacology and therapeutic use in acid-related disorders

Omeprazole is the first of a new class of drugs, the acid pump inhibitors, which control gastric acid secretion at the final stage of the acid secretory pathway and thus reduce basal and stimulated acid secretion irrespective of the stimulus. In patients with duodenal or gastric ulcers, omeprazole as a single 20 mg daily dose provides more rapid and complete healing compared with ranitidine 150 mg twice daily or 300 mg at nighttime, or cimetidine 800 or 1000 mg/day. Patients poorly responsive to treatment with histamine H2-receptor antagonists respond well to omeprazole--most ulcers healed within 4 to 8 weeks of omeprazole 40 mg/day therapy. Omeprazole 20 or 40 mg/day has been administered as maintenance therapy for peptic ulcer disease for up to 5.5 years with very few ulcer recurrences. In patients with erosive or ulcerative oesophagitis, omeprazole 20 or 40 mg/day produces healing in about 80% of patients after 4 weeks, and is superior to ranitidine with respect to both healing and symptom relief. Healing rates of greater than 80% are achieved after 8 weeks in patients with severe reflux oesophagitis unresponsive to H2-receptor antagonists. Maintenance therapy with a daily 20 mg dose prevents relapse in about 80% of patients over a 12-month period. Omeprazole is considered to be the best pharmacological option for controlling gastric acid secretion in patients with Zollinger-Ellison syndrome. Daily dosages of 20 to 360 (median 60 to 70 mg successfully reduce basal acid output to target levels (less than 10 mmol/h or less than 5 mmol/h in patients with severe oesophagitis or partial gastrectomy) during treatment for up to 4 years. Omeprazole is well tolerated in short term studies (up to 12 weeks); the reported incidence of serious side effects (about 1%) being similar to that seen in patients treated with an histamine H2-receptor antagonist. The longer term tolerability of omeprazole has been investigated in patients treated for up to 5.5 years. Slight hyperplasia, but no evidence of enterochromaffin-like (ECL) cell dysplasia or neoplasia or ECL cell carcinoids has been reported. ECL cell carcinoids have been observed in rats after life-long treatment with high doses of omeprazole or ranitidine, or in rats with partial corpectomy; the weight of experimental evidence indicates that this is a result of prolonged hypergastrinaemia.(ABSTRACT TRUNCATED AT 400 WORDS)

Use of omeprazole in patients with Zollinger-Ellison syndrome

Omeprazole, a substituted benzimidazole, has been shown to be a potent inhibitor of gastric acid secretion in patients with Zollinger-Ellison syndrome (ZES). We review our experience, as well as the published data on 210 patients with ZES who have required omeprazole for control of gastric acid hypersecretion over the past seven years. The dose of omeprazole required in individual patients ranged from 10 to 180 mg/24 hr with 20-60% requiring a split dosage regimen. Omeprazole was effective in approximately 99% of the patients over a period ranging from 0.5 to 54 months. Twenty-four percent of patients required an increase in omeprazole dose, while 26% required a decrease in dose. Adverse effects attributable to omeprazole were reported in 2% of patients, and in all cases, they were mild (ie, rash, constipation, headache). There was no effect of omeprazole on serum gastrin concentration or on gastric endocrine cells in three studies. Although one patient with multiple endocrine neoplasia, type-I syndrome (MEN-I) in this series developed a gastric carcinoid while taking omeprazole, evidence is presented that suggests the presence of MEN-I per se may be important in determining the development of gastric carcinoid in patients with ZES. It is concluded that omeprazole is safe and effective in patients with ZES, and in these patients, it is the drug of choice for the management of gastric acid hypersecretion. However, yearly assessment is indicated to clearly evaluate the long-term risk of gastric carcinoid as well as therapy directed at the gastrinoma itself.

Contributions of the Zollinger-Ellison syndrome

The salient contributions of the Zollinger-Ellison syndrome have made it unique. No pancreatic endocrine tumor described before (insulinoma) or subsequently (glucagonoma, somatostatinoma, vipoma, pancreatic-polypeptidoma) has been the topic of such a variety of studies, or has been such an inspiration and rich source of new ideas for investigation and ultimate improvement in patient care.

Gastrinoma in multiple endocrine neoplasia type 1

Extensive experience from patients with gastrinoma as part of the multiple endocrine neoplasia type 1 (MEN 1) syndrome has revealed that MEN 1-gastrinoma patients show important differences from patients with sporadic gastrinoma. These differences comprise clinical, pathological and biochemical features, but are especially pertinent to the therapeutic approach. Therefore, the diagnosis of the MEN 1 syndrome is of great clinical importance to the gastrinoma patient and his family.

APUD update

Apudomas are a diffuse group of tumors that have interested surgeons for a long time. With recent developments in their radiological localization and pharmacological control, they are now treated in a truly multidisciplinary approach. In this chapter, recent developments in the radiological, surgical, and medical approaches to these tumors are reviewed. Emphasis is placed on how non-surgical developments have affected the surgical treatment of specific apudomas. Resulting changes in surgical philosophy are also reviewed.

Omeprazole in the treatment of Zollinger-Ellison syndrome: a 4-year international study

The H+, K(+)-ATPase inhibitor omeprazole has been made available on a compassionate basis for patients with Zollinger-Ellison syndrome considered resistant to, or with side-effects on, histamine H2-receptor antagonists. By December 1985, the first 80 patients, from 46 centres in 11 countries, had been treated for periods of 2 days to 4 years. Basal acid output was decreased to the desired level of less than 10 mmol.hour-1, and symptoms were rapidly relieved. Acid secretion and laboratory variables were checked regularly and endoscopic examinations made at intervals. Dosage was adjusted primarily on the basis of basal acid output, but also if symptoms recurred. The starting dose was generally 60 mg daily and the median dose ranged between 60 and 70 mg daily over the study period. There was no evidence of tachyphylaxis. More than 90% of the patients were successfully controlled on total daily doses of 120 mg or less; one-third of patients required divided doses. Tolerance was good: there were no obvious drug-related effects on laboratory variables, including fasting serum gastrin, and there were very few adverse events. Thirteen patients died (11 of the primary disease and two of other causes), four underwent successful tumour resection, six underwent total gastrectomy (though acid secretion was controlled in five), four patients' treatment was changed to other medical therapy, and one was lost to follow-up. Omeprazole thus appears to be both safe and very effective in controlling acid hypersecretion in this group of patients, and to provide a suitable alternative to total gastrectomy.