Omeprazole in peptic ulcers resistant to histamine H2-receptor antagonists

What is an intractable duodenal ulcer and how should it be managed?

An intractable duodenal ulcer is an ulcer that has not healed after 8 weeks of full-dose treatment with a modern anti-ulcer drug. Such ulcers are relatively rare--perhaps five in 100 patients will have intractable duodenal ulceration. The differential diagnosis includes non-compliance as a cause of continuing ulceration, hypersecretion of gastric acid or other rare causes of ulcers in the duodenum. Investigations should include biopsy of the continuing ulceration at endoscopy, measurement of fasting plasma gastrin and routine haematology and biochemistry profiles. An intractable duodenal ulcer can be treated either by using a powerful antisecretory regimen (high doses of ranitidine or famotidine or a conventional dose of omeprazole), by changing to tripotassium dicitrato bismuthate or, in exceptional circumstances, by extremely careful surgical intervention.

An open trial of long-term therapy with lansoprazole in patients with peptic ulceration resistant to extended high-dose ranitidine treatment

Forty-two patients with peptic ulceration of the duodenum, stomach or oesophagus, who had not responded to 3 or more months of high-dose treatment with ranitidine (450 or 600 mg/day), were treated with oral lansoprazole at 30-60 mg daily. In 40 patients (95.2%) the ulcers healed within 2-12 weeks. In the remaining 2 patients healing took several months but eventually all ulcers healed. After healing, 40 patients underwent long-term maintenance treatment with 30-60 mg lansoprazole daily for 1-3 years (continuing). During maintenance therapy with lansoprazole, no endoscopically verified relapses occurred when the drug was taken regularly. In 1 patient treatment had to be discontinued because of a drug-related colitis that disappeared soon after treatment had been stopped. There were no significant changes in routine laboratory tests in any patient. Basal serum gastrin concentrations, which were already elevated by the previous high-dose ranitidine treatment (125 +/- 25 pg/ml), rose to four times the normal values after 4 weeks of treatment with lansoprazole (255 +/- 65 pg/ml). Thereafter no further increases in basal serum gastrin concentrations were observed, even after 3 years of administration. The volume density of argyrophilic cells in the oxyntic mucosa increased slightly during lansoprazole treatment; until now no dysplasia of the enterochromaffin-like cells has been observed. In conclusion, 30-60 mg lansoprazole daily healed ranitidine-resistant peptic ulcers, and subsequent maintenance therapy with 30-60 mg lansoprazole daily was found to be highly effective and safe over the time observed.

Long-term omeprazole treatment in resistant gastroesophageal reflux disease: efficacy, safety, and influence on gastric mucosa

BACKGROUND & AIMS

The efficacy and safety of long-term acid suppression remains a subject for debate. We report data from patients with refractory reflux esophagitis who were undergoing maintenance therapy with >/=20 mg omeprazole daily for a mean period of 6.5 years (range, 1.4-11.2 years).

METHODS

Patients with severe reflux esophagitis resistant to long-term therapy with H(2)-receptor antagonists and who were not eligible for surgery were evaluated at least annually for endoscopic relapse and histological changes in the gastric corpus.

RESULTS

In 230 patients (mean age, 63 years at entry; 36% were >/=70 years), there were 158 relapses of esophagitis during 1490 treatment years (1 per 9.4 years), with no significant difference in relapse rates between Helicobacter pylori-positive and -negative patients. All patients rehealed during continued therapy with omeprazole at the same or higher dose. The annual incidence of gastric corpus mucosal atrophy was 4.7% and 0.7% in H. pylori-positive and -negative patients, respectively, which was mainly observed in elderly patients who had moderate/severe gastritis at entry. In patients with baseline moderate/severe gastritis, the incidences were similar: 7.9% and 8.4%, respectively. Corpus intestinal metaplasia was rare, and no dysplasia or neoplasms were observed. The adverse event profile was as might be expected from this elderly group of patients.

CONCLUSIONS

Long-term omeprazole therapy (up to 11 years) is highly effective and safe for control of reflux esophagitis.

Biochemical and pharmacological properties of a new proton pump inhibitor, 2-amino-4,5-dihydropyrido[1,2-a]thiazolo [5,4-g] benzimidazole (YJA20379-5)

This study was designed to determine biochemical and pharmacological properties of a newly synthesized benzimidazole derivative, 2-amino-4,5-dihydropyrido [1,2-a] thiazolo [5,4-g] benzimidazole (YJA20379-5) in vitro and in vivo. In the leaky membrane vesicles of pig gastric mucosa, YJA20379-5 inhibited the K(+)-stimulated H+,K(+)-ATPase activity in a concentration- and time-dependent manner, with IC50 values being 43 microM and 31 microM at pH 6.4 and 7.4, respectively. YJA20379-5, given intraduodenally, had a potent inhibitory effect on the gastric acid secretion in pylorus-ligated rats. The ED50 value for acid secretion was 15.4 mg/kg. YJA20379-5, administered orally, also suppressed gastric damages induced by water-immersion stress, indomethacin and ethanol, and duodenal damage induced by mepirizole in rats; the ED50 values were 17.6, 4.7, 3.0 and 18.7 mg/kg, respectively. Furthermore, repeated oral administration of YJA20379-5 accelerated the spontaneous healing of acetic acid-induced gastric ulcers in rats. It is concluded that the antisecretory activity of YJA20379-5 appears to be associated with inhibition of H+,K(+)-ATPase, while its antigastric and antiduodenal lesion activities are primarily related to the antisecretory effect.

Twice daily nizatidine or ranitidine is superior to once daily dosing in elevating 24 h intragastric pH in patients with duodenal ulcer disease

The present study was performed in six asymptomatic patients with a history of resistant duodenal ulcers in whom 24 h intragastric pH, gastric juice pepsin and PGE2 concentrations, as well as serum gastrin concentrations, were measured. We wanted to compare the effects on these parameters of a single night time (q.h.s.) dose of nizatidine 300 mg (N1), nizatidine 300 mg b.i.d. (N2), ranitidine 300 mg q.h.s. (R1) or ranitidine 300 mg b.i.d. (R2) compared with placebo (P). During the night (22.00-08.00 h), all treatments gave a higher mean pH than P, but during the day (08.00-22.00 h) the mean pH was higher than P only for patients administered R2 and N2. Doubling the dose of nizatidine (N2 vs N1) or ranitidine (R2 vs R1) increased the mean daytime pH, but had no effect on night time pH. The daytime pepsin concentration was unaffected by H2-receptor antagonists, while night time pepsin was lower with R1 and R2, but not with N1 or N2. The night time gastrin concentration was unaffected by H2-receptor antagonists; doubling the dose of the H2-receptor antagonist (R2 vs R1 and N2 vs N1) increased daytime gastrin concentration. During the night, each treatment increased PGE2 concentration by at least six-fold compared with P. Thus, where it is therapeutically indicated to achieve greater suppression of acid secretion, doubling the total daily dose by dosing with twice daily versus once daily night time nizatidine or ranitidine is efficacious.

Long-term strategies for peptic ulcer

Commonly when treatment is stopped most peptic ulcers recur. The prevention of ulcer recurrence by continuous long-term therapy, usually with H2-receptor antagonists, provides effective and convenient management in patients at risk in order to reduce the chance of relapse, complications, and associated mortality. High relapse rates of peptic ulcer suggest the need for continuous H2-antagonists in elderly patients, those receiving NSAID, aspirin or anticoagulants, those with coexistent medical conditions and those with previous haemorrhage or perforation. Patients suitable for intermittent therapy include those who are < 60 years, with no previous ulcer complications, no coexistent medical conditions and few recurrences. Long-term H2-antagonists have an enviable safety profile and are cost effective. Despite this, the possibility of permanent cure of peptic ulcer by Helicobacter pylori eradication suggests that long-term therapy may not be needed. We face the exciting prospect of placing peptic ulcer into the annals of history.

Long-term omeprazole therapy in peptic ulcer disease: gastrin, endocrine cell growth, and gastritis

BACKGROUND

The effects of chronic drug-induced hypergastrinemia on the exocrine and endocrine stomach are still incompletely understood. Chronic hypergastrinemia in rats and humans is associated with gastric argyrophil cell hyperplasia.

METHODS

Seventy-four patients with chronic ranitidine-resistant ulcerations were treated chronically with omeprazole (median observation period 48 [6-84] months).

RESULTS

Median fasting serum gastrin levels increased from a pretreatment value of 74-145 pg/mL after 3 months. No further increase was observed thereafter. The finding of atrophic gastritis increased from 1.8% to 20.8% after 5 years. A doubling of the mean argyrophil cell volume density (0.36% vs. 0.74% after 5 years; P < 0.01%) was paralleled by a decrease in the normal endocrine cell growth pattern from 64.3% to 33.3% and an increase in micronodular hyperplasia (8.9% vs. 16.7%). These changes correlated with the severity of corpus gastritis and seemed to be more disease- than drug-related. No statistically significant changes were observed in the antral G- and D-cell volume densities under therapy.

CONCLUSIONS

Long-term omeprazole therapy in humans results in moderate hypergastrinemia and a significant argyrophil cell hyperplasia, which are correlated to the grade of corpus gastritis. Because hypergastrinemia and gastritis are closely related, it is difficult to quantitatively assess their respective role in this process.

Antiulcer therapy

Perhaps older drugs to treat ulcers, such as antacids, are just as effective as the newer drugs, but veterinarians have all but abandoned these drugs in favor of H2-receptor antagonists, sucralfate, and omeprazole. For most patients, one of the H2-receptor antagonists or sucralfate is probably the initial drug of choice. For patients refractory to these drugs or for which once-a-day dosing is desirable, omeprazole has an advantage. The doses for these drugs are listed in Table 1. Patients presented with acute bleeding ulcers should be managed with emergency therapy. Fluid therapy and blood transfusions are the essential elements of the initial therapy. Surgical resection of the ulcers may be necessary, and most patients should be administered H2-receptor antagonists or sucralfate while they recuperate. Longer term therapy with antiulcer drugs will depend on the predisposing factors that initiated the ulcers. The practice of lavage of the stomach with iced saline or epinephrine to stop bleeding from gastric ulcers is not effective. A common cause of ulcers in small animals is the administration of NSAIDs. Ulcers caused by these agents should be managed like any other ulcers. Fortunately, if ulcers are diagnosed early, they usually heal once the NSAID is discontinued. Unfortunately, many NSAID-induced ulcers identified postmortem did not produce clinical signs, and the ulcers may not be apparent until severe bleeding occurs. In cases in which patients are at risk for developing ulcers from NSAIDs, there may be an advantage in administering the synthetic prostaglandin misoprostol. In many patients that are sensitive to the GI irritation of NSAIDs, switching from one NSAID to another may alleviate some of the signs. Buffered aspirin may be somewhat less irritating than plain uncoated aspirin but will not completely prevent ulcers. The administration of enteric-coated aspirin tablets to dogs is discouraged, because systemic absorption from these tablets is unpredictable.

Review article: metabolic consequences of long-term inhibition of acid secretion by omeprazole

Metabolic sequelae of profound and long-lasting inhibition of gastric acid secretion by omeprazole have largely been neglected. Data from long-term studies suggest that vitamin B12 stores decrease slightly over several years, although this was not clinically relevant within the first 4 years of therapy. Additionally, it cannot be completely ruled out that patients with an increased iron demand may develop iron deficiency, but data available at present do not provide any evidence that iron malabsorption is to be expected under normal conditions. Protein homeostasis and calcium metabolism seem to be unaffected by long-term omeprazole therapy. Based upon present experience, serum cobalamin concentration should be monitored in patients undergoing omeprazole therapy for several years.

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)

The course of peptic ulcer disease

Peptic ulcer disease usually has periodic exacerbations and remissions. Pain can disappear without total healing of the ulcer crater and can be absent when an ulcer is present. Changes in the incidence of ulcer disease have been noted in recent years. Genetic predisposition, infection with H. pylori, and the use of anti-inflammatory drugs are involved in causation. Stress; the use of alcohol, tobacco and caffeine; and other diseases have been implicated as etiologic factors. Ulcer pain has a recognizable pattern, but the symptoms can be variable, particularly in older people and in patients taking ulcerogenic medications. The familiar complications of hemorrhage, perforation, and obstruction still occur, and nonulcer dyspepsia has not been fully explained. Duodenal ulcers have a disturbing tendency to return; new therapeutic approaches offer hope.

Omeprazole. Overview and opinion

Omeprazole, a substituted benzimidazole, is a specific inhibitor of the enzyme H+/K(+)-ATPase, which is found on the secretory surface of the parietal cell. This enzyme, the "proton pump," catalyzes the final step in acid secretion. Omeprazole is a powerful inhibitor of gastric acid secretion. At the time of writing, omeprazole has been licensed in the United States for the treatment of severe grades of gastroesophageal reflux disease (GERD) as well as GERD unresponsive to treatment with currently available agents, and for the treatment of Zollinger-Ellison syndrome and other gastric hypersecretory states. Most recently, it has been recommended by the FDA advisory committee for approval as first-line therapy in duodenal ulcer disease.

Clinical pharmacology of omeprazole

Omeprazole is a specific inhibitor of H+,K(+)-ATPase or 'proton pump' in parietal cells. This enzyme is responsible for the final step in the process of acid secretion; omeprazole blocks acid secretion in response to all stimuli. Single doses produce dose-dependent inhibition with increasing effect over the first few days, reaching a maximum after about 5 days. Doses of omeprazole 20mg daily or greater are able to virtually abolish intragastric acidity in most individuals, although lower doses have a much more variable effect. Omeprazole causes a dose-dependent increase in gastrin levels. Omeprazole must be protected from intragastric acid when given orally, and is therefore administered as encapsulated enteric-coated granules. Absorption can be erratic but is generally rapid, and initially the drug is widely distributed. It is highly protein-bound and extensively metabolised. Its elimination half-life is about 1h but its pharmacological effect lasts much longer, since it is preferentially concentrated in parietal cells where it forms a covalent linkage with H+,K(+)-ATPase, which it irreversibly inhibits. Omeprazole binds to hepatic cytochrome P450 and inhibits oxidative metabolism of some drugs, the most important being phenytoin. Omeprazole has produced short term healing rates superior to the histamine H2-receptor antagonists in duodenal ulcer, gastric ulcer and reflux oesophagitis. It has also been shown to be highly effective in healing ulcers which have failed to respond to H2-receptor antagonists, and has been extremely valuable in treating patients with Zollinger-Ellison syndrome.

Omeprazole in the treatment of peptic ulcers resistant to H2-receptor antagonists

Thirty patients with peptic ulcers resistant to at least 8 weeks of continuous therapy with full-dose H2-receptor antagonists alone or followed by other anti-ulcer drugs, were treated with the gastric proton pump inhibitor omeprazole (40 mg), administered orally once daily for up to 8 weeks. The study design was non-comparative and open; healing was verified by endoscopy. After only 2 weeks of treatment, 21 out of 23 (91%) duodenal ulcer patients were healed, as well as 2 out of 2 patients with both duodenal and gastric ulcer and 1 out of 3 patients with prepyloric ulcer. After 4 weeks, all duodenal ulcers, 1 out of 2 gastric ulcers and 2 out of 3 pre-pyloric ulcers were healed. A further month of therapy healed the gastric ulcer to give an overall healing rate of 97% and leaving only one patient (pre-pyloric ulcer) unhealed at the end of the study. Of 19 patients suffering ulcer symptoms at entry, only two patients reported any symptoms at 2 weeks and one of these (who remained unhealed) continued to have symptoms throughout the study. One patient reported mild asthenia; otherwise, no clinical or biochemical side-effects were recorded. It is concluded that omeprazole is highly effective in healing refractory peptic ulcers.

Omeprazole and ranitidine in duodenal ulcer healing. Analysis of comparative clinical trials

Ten double-blind randomized studies with omeprazole versus ranitidine in duodenal ulcer healing have been published. The total number of patients in the trials amounted to 2225. To detect treatment differences, a meta-analysis was performed. After 2 and 4 weeks of treatment results have been evaluated. After 2 weeks of treatment omeprazole produced higher healing rates than ranitidine in nine studies. However, at 4 weeks numerical differences in favour of omeprazole were found in nine studies. Relief of ulcer symptoms occurred more rapidly with omeprazole than ranitidine. No major clinical or biochemical side effects were recorded. However, no data are available about maintenance therapy in double-blind randomized studies comparing both drugs or about rebleeding rates in bleeding duodenal ulcer treatment.

Omeprazole (20 mg o.m.) versus ranitidine (150 mg b.d.) in duodenal ulcer healing and pain relief

The object of this double-blind, multicentre study was to compare duodenal ulcer healing rates after 2 to 4 weeks of treatment with either 20 mg omeprazole o.m. or 150 mg ranitidine b.d. One hundred and eighty-one patients were randomized: 91 received omeprazole and 90 received ranitidine. In a per protocol analysis at 2 weeks, 63% of the patients were healed on omeprazole and 65% of the patients were healed on ranitidine (N.S.); at 4 weeks 91% were healed in the omeprazole group and 96% were healed in the ranitidine group. There were no differences in ulcer symptom relief between the two groups. There were no significant changes in laboratory values in either of the groups. Adverse events were few and mainly mild and transient. We conclude that both omeprazole (20 mg o.m.) and ranitidine (150 mg b.d.) result in rapid, ulcer healing rates.

Human gastric acid secretion following repeated doses of AG-1749

The effect of increasing doses (15 mg, 30 mg and 60 mg) of the substituted benzimidazole, AG-1749, on gastric acid secretion and fasting serum gastrin concentration has been studied after repeated administration to healthy volunteers. AG-1749 produced a dose-dependent and profound decrease in basal and stimulated gastric acid secretion in all volunteers, with almost total suppression at the highest dose. The extent of inhibition increased between Day 2 and Day 8 with the 15 and 30 mg doses of AG-1749. The inhibitory effect of AG-1749 appears to be fully reversible as control levels of acid output were reached 7 days after drug withdrawal. Seven days' dosing with 60 mg AG-1749 induced a more than threefold increment of fasting serum gastrin concentration, but this increase was still within the normal range. Seven days after cessation of dosing, fasting serum gastrin concentration returned to a pre-dose level.

Changing pattern of admissions and operations for duodenal ulcer

The admission rates for duodenal ulcer (DU) and the effect of H2-receptor antagonists (H2RA), introduced in the Trent Region of the UK in 1977, were examined. The admission rates are expressed per 10(6) of resident population. The use of H2RA has risen 3.7-fold (from 1978 to 1983), yet overall admission rates for perforation have changed little: 99 in 1972-76 (pre-H2RA period) compared with 103 in 1977-84 (H2RA period). Admission rates for haemorrhage have risen by 8 per cent, from 130 to 140 (P less than 0.01). However, the overall rates conceal large increases (P less than 0.01) in the admission rates for those aged greater than or equal to 65 years, of 33 per cent (from 264 to 352) for perforation and of 28 per cent (from 381 to 489) for haemorrhage. Emergency admissions for uncomplicated DU were unchanged: 88 in 1972-76 and 89 in 1977-84. However, the proportions operated on fell by 58 per cent (P less than 0.01), from 30 per cent of admissions in the pre-H2RA period compared with only 12 per cent in the H2RA period. Waiting-list admissions for uncomplicated DU fell by 43 per cent, from 187 to 106 (P less than 0.01), and the proportions operated on fell from 162 to 76; the combined effect resulted in a reduction of 53 per cent in the operation rates (P less than 0.01). In Rotherham, the use of H2RA has risen 6.2-fold (from 1978 to 1983) and they were generally used intermittently in 1976-78 and later for maintenance therapy and high-dose treatment. Yet admissions for perforation and for haemorrhage were unchanged. Emergency admissions for uncomplicated DU rose by 40 per cent, from 130 in 1972-75 to 182 in 1976-84, but the proportions operated on fell markedly, from 20 to 6 per cent (P less than 0.01); waiting-list admissions fell in 1976-78 by 29 per cent and in 1979-84 by 73 per cent. The proportions operated on in the three periods fell from 74 to 53 per cent and 25 per cent respectively and these two factors led to decreases in elective surgery of 50 per cent in 1976-78 and 91 per cent in 1979-84 (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Omeprazole in the treatment of duodenal ulcer

Omeprazole is the most effective antisecretory agent available today. Open and dose-comparative studies have documented that at dosages of 20 mg/day or more, the drug produces duodenal ulcer healing rates of 90-100% after 4 weeks. Controlled trials show that omeprazole, 20-40 mg/day, is superior to cimetidine and ranitidine in healing duodenal ulcer, with a median therapeutic gain of 21% at 2 weeks and 15% at 4 weeks. Ulcer symptom relief is also more pronounced and faster with omeprazole than with H2-receptor antagonists. No significant side-effects attributable to treatment with omeprazole have appeared in any of these studies or in the accumulated experience from several thousand patients treated with omeprazole. No tendency to an increase in recurrence rate after discontinuation of treatment with omeprazole has been shown. In summary, omeprazole constitutes a major advance in the short-term treatment of duodenal ulcer, giving fast and pronounced healing and symptom relief.

Omeprazole in the management of refractory duodenal ulcer

In about 5-10% of duodenal ulcer patients, ulcer healing is difficult or impossible to achieve with H2-receptor antagonists. Such patients are considered to have a refractory ulcer. The cause of refractoriness remains unknown. Some patients have high acid secretion or inadequate acid suppression on treatment, but this has not been confirmed by all investigators or in all patients. Abnormalities in mucosal defence presumably exist, but none have as yet been identified. The principal medical therapeutic approach has been to continue suppressing acid or to use mucosal protective agents. Increasing the duration of H2-receptor antagonist treatment at the same dose had little effect, but doubling or trebling the dose improved healing rates in open studies. Markedly higher healing rates occurred when treatment was changed from cimetidine to ranitidine (which is more potent) in open studies, but this was not always confirmed in controlled studies. Adding the anti-muscarinic, pirenzepine, to cimetidine to achieve better acid inhibition, improved healing rates in some controlled studies but not in others. The mucosal protectant, colloidal bismuth subcitrate, proved significantly more effective than H2-receptor antagonist treatment, but the drug is suitable only for short-term therapy. Controlled studies with omeprazole confirmed the results of open studies and proved the product to be superior to continued H2-receptor antagonist treatment in healing refractory duodenal ulcer. Open studies using maintenance treatment with low-dose omeprazole suggest that such therapy is effective in keeping refractory duodenal ulcer healed.

Histamine H2-receptor antagonists

The first histamine H2-receptor antagonists were developed in the early 1970s, and they have a dominant role in today's management of peptic ulceration. The original regimens using either cimetidine or ranitidine attempted to control acidity across the 24 hours, but more 'modern' regimens use a large single dose of the H2-blocker in the evening, which produces a pulse of decreased intragastric acidity during the night with a normal acidity in the daytime. High-dose regimens using a new generation of extremely potent histamine H2-receptor antagonists may improve ulcer healing rates at 4 weeks, and may be particularly useful for the management of either severe oesophagitis or intractable duodenal ulceration.

Effect of high dose omeprazole on gastric pepsin secretion and serum pepsinogen levels in man

To investigate the effect of omeprazole on serum and urinary pepsinogens and on gastric pepsin, 8 healthy male volunteers were studied before and after 9 days of treatment with omeprazole 60 mg/day p.o. Fasting serum samples and 24 h urine specimens were obtained, and gastric contents were aspirated at 15-min intervals, 4 prior to and 6 during pentagastrin 1.5 micrograms.kg-1.h-1 i.v. during intra-gastric perfusion with NaCl 0.9% and phenol red 3 mg.ml-1 as an inert recovery marker. Basal and pentagastrin-stimulated volume and acid secretion were significantly decreased. The basal and pentagastrin stimulated pepsin output remained unchanged but pepsin concentration in gastric secretion was increased. Administration of omeprazole resulted in a significant increase in the serum PGA and PGC levels. The 24-h urinary excretion of PGA increased, but that of PGC remained unchanged, and so did the renal clearances of creatinine and pepsinogen A. The renal clearance of pepsinogen C decreased. It was concluded that omeprazole did not affect gastric pepsin output, but, due to the decreased volume output, the concentration of pepsin in the gastric secretion was increased. Omeprazole increased the serum levels of pepsinogen A and C because more pepsinogen was released into the systemic circulation. This might be due to greater back-diffusion of pepsinogen from the gastric mucosa into the systemic circulation as a result of the higher pepsinogen concentration in gastric secretion.

Future trends in the management of peptic ulcer disease

Future trends in the short- and long-term management of peptic ulcer disease are considered. The present state of development of pharmacologic agents for the short-term healing of duodenal and gastric ulcer is impressive, and high rates of healing with rapid symptom relief can be safely achieved with several agents. The problem of ulcer recurrence has not been solved, although new work concerning the role of Campylobacter pylori holds promise. The mortality of acute gastrointestinal haemorrhage remains unacceptably high, especially in the elderly. Therapeutic endoscopy may be effective in decreasing the death rate from bleeding.

Is chronic long-term inhibition of gastric secretion really dangerous?

Powerful gastric secretion inhibitors produce cancer in their target organ, the stomach, in experimental animals. The possible mechanisms of the carcinogenic effect are discussed under the headings of the potential noxious change in the gastric luminal contents, as is the possibility that the drugs act as epigenetic or genotoxic carcinogens. Whatever the mechanisms of the drug-induced carcinogenesis, it is clear that there is a toxicologic hazard, which must be assessed rationally and not by means of sophistry. Until the dangers posed by powerful gastric secretory inhibitors to man have been better evaluated, these drugs must not be used for treatment other than of patients with gastrinomas.

Recent developments in peptic ulcer treatment

Since peptic ulcer disease is a multifactorial disease, the ideal therapeutic approach would be to use different drugs for different ulcers. In the past few years some studies have been published suggesting that subgroups of patients with peptic ulcer might particularly benefit from specific forms of therapy. In the present report the available evidence has been critically reviewed.