Primary gastroduodenal prophylaxis with omeprazole for non-steroidal anti-inflammatory drug users

Non-steroidal anti-inflammatory drug toxicity in the upper gastrointestinal tract

Non-steroidal anti-inflammatory drug (NSAID) toxicity in the upper gastrointestinal tract is the most common serious drug-induced toxicity reported to drug regulatory authorities. In the last two decades, the rediscovery of H. pylori, development of potent ulcer-healing drugs and specific Cox-II inhibitors have opened new horizons in the management of NSAID toxicity. A Working Party composed of gastroenterologists and rheumatologists in the Asia-Pacific region met in Cairns, Australia, in 1999 to review the literature and develop appropriate guidelines. Recommendations were made based on the latest existing evidence. The importance of clinical events as study endpoints was emphasized. While differences exist between NSAIDs and aspirin, most studies have shown that advanced age, history of peptic ulcer disease, serious concomitant illnesses and coprescription of NSAID/aspirin with anticoagulants and steroids are high risk factors. These patients should be considered for prophylactic anti-ulcer therapy. Helicobacter pylori infection may aggravate the toxicity of NSAIDs and, in selected cases, should be treated before NSAID/aspirin is prescribed. Proton pump inhibitors and misoprostol are the most promising agents in preventing gastric and duodenal ulcers. When NSAID/aspirin needs to be continued in patients who develop an NSAID-related ulcer, proton pump inhibitors offer the best healing effect. With the discovery of cyclo-oxygenase isoforms (Cox-I and Cox-II), preferential and specific Cox-II inhibitors have been developed. While early clinical data have suggested promising antiinflammatory effects and improved safety profile in the gastrointestinal tract, several key issues on long-term safety remain unresolved. The use of potent anti-ulcer therapy, treatment of H. pylori infection and the development of Cox-II inhibitor will change the scenario of NSAID/aspirin-related gastrointestinal toxicity in the next millennium.

Review article: non-steroidal anti-inflammatory drugs and Helicobacter pylori

Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori are well-recognized causes of gastroduodenal mucosal damage. This damage is mediated through the effects of both agents on acid secretion, neutrophil activity and function, and prosta- glandin metabolism. Clinical trials on the interrelation- ship between H. pylori, NSAIDs and gastroduodenal mucosal injury have yielded conflicting results. No consensus has been reached on what recommenda- tions should be implemented with regard to H. pylori eradication in patients on long-term NSAID therapy. At present, the presence of H. pylori is identified at endoscopy and eradication is carried out in symptomatic patients. Asymptomatic patients remain a dilemma that requires further investigation. Clinical practice will continue to be tailored to a patient's individual requirements. Therefore, in patients at risk of gastrointestinal haemorrhage, and on NSAID therapy, acid suppression therapy should be prescribed.

The gastroduodenal toxicity of nonsteroidal anti-inflammatory drugs: a review of the literature

Nonsteroidal anti-inflammatory drugs (NSAIDs) are popular and important for the treatment of inflammation and pain. However, conventional NSAIDs are intrinsically toxic to the gastroduodenal (GD) mucosa. The literature can, and should, guide us towards safer prescribing of NSAIDs. Factors known to increase the risk of GD toxicity include: history of peptic ulcer disease; advanced age; high doses; and coadministration of aspirin, anticoagulants or corticosteroids. Patients with any one of these risk factors, with the possible exception of age alone, should receive gastroprotective prophylaxis with proton pump inhibitors or misoprostol. Standard dose H2 antagonists do not protect against NSAID-induced gastric ulcers and are unsuitable for prophylaxis. Awareness of risk factors and appropriate prophylactic agents will minimize the risk to patients. Whether the new generation of highly selective COX-2 inhibitors and nitric oxide-donating NSAIDs are safer drugs in long-term use be remains to be proven, though initial clinical trial data are positive.

Pantoprazole versus one-week Helicobacter pylori eradication therapy for the prevention of acute NSAID-related gastroduodenal damage in elderly subjects

AIM

To compare the efficacy of pantoprazole vs. a one-week Helicobacter pylori eradication therapy for the prevention of NSAID-related gastroduodenal damage.

METHODS

Patients over 60 years old with symptoms and/or a history of ulcer who needed NSAID treatment were evaluated by endoscopy. H. pylori positive subjects who had no severe gastroduodenal lesions were randomized to take, concomitantly with NSAID therapy, either: (i) pantoprazole 40 mg daily plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. for 1 week (35 subjects, Group PAC) or (ii) pantoprazole 40 mg daily for 1 month (34 subjects, Group P). Endoscopy was repeated after 1 month.

RESULTS

A significantly higher incidence of severe gastroduodenal damage was found in Group PAC than in Group P (29% vs. 9%, P<0.05). The percentages of patients worsened, unchanged and improved after 1 month were, respectively: Group PAC: 46%, 46%, and 9% and Group P: 7%, 65%, and 29% (P<0.0008). The percentage of H. pylori-negative subjects was 89% in Group PAC and 52% in Group P (P=0.0009). The incidence of gastroduodenal damage was higher in Group PAC treatment failures than in cured patients (50% vs. 25.8%, P=ns).

CONCLUSION

One month of pantoprazole was more effective than a proton pump inhibitor-based triple therapy in the prevention of gastroduodenal damage in elderly H. pylori-positive NSAID users.

Nonsteroidal anti-inflammatory drug gastropathy

By inhibiting prostaglandin synthesis, nonsteroidal anti-inflammatory drugs (NSAIDs) compromise gastroduodenal defense mechanism including blood flow and mucus/bicarbonate secretion. This has led to NSAIDs being the most widely reported drug cause of adverse events. While NSAIDs also cause dyspepsia, inhibition of prostaglandin synthesis may reduce this from even higher levels that would otherwise prevail and mask ulcer-related dyspepsia, making anticipatory management difficult. On average, the risk of ulcer complications increases 4-fold, resulting in 1.25 additional hospitalizations per 100 patient-years according to one estimate. Older patients, those with a past history, and those taking anticoagulants or corticosteroids are at higher risk. Risk is dose dependent and is lower with ibuprofen at low doses than with other NSAIDs. It is unlikely that Helicobacter pylori increases the risk, and under some circumstances it may be protective. Selective inhibitors of the inducible cyclooxygenase 2 spare gastric mucosal prostaglandin synthesis and do not damage the gastric mucosa. Their place in therapy, compared with use of misoprostol or proton pump inhibitors, is currently emerging. Future competitors may include nitric oxide-donating, zwitterionic, or R-enantiomer NSAIDs.

Prevention of non-steroidal anti-inflammatory drug-induced gastrointestinal mucosal injury: risk factors for serious complications

BACKGROUND

1-2% of all patients under non-steroidal anti-inflammatory drug therapy are exposed to serious upper gastrointestinal complications. The policy of prevention of non-steroidal anti-inflammatory drug-induced gastrointestinal mucosal injury by using misoprostol or suppressing acid secretion is still a matter of debate.

AIMS

To discuss the effectiveness of prophylaxis of a gastrointestinal complication during non-steroidal anti-inflammatory drug treatment, according to the number and relevance of risk factors.

PATIENTS

A total of 8.843 patients with rheumatoid arthritis, admitted to the widest prospective multicentre mega-trial, on 6-month complication prevention of non-steroidal anti-inflammatory drug-induced ulcers.

METHODS

The results are presented in terms of the number of patients to be treated (number needed to treat) in order to prevent one serious upper gastrointestinal complication, and corrected for the number of patients, that receiving the prophylaxis therapy, would lead to one additional withdrawal (number needed to harm).

RESULTS

The base-line risk for a complication strongly depended on the number and relevance of risk factors: history of peptic ulcer disease, of gastrointestinal bleeding, of cardiovascular disease, and age. In the general study population, the relative risk reduction of gastrointestinal complications with misoprostol was 40%: thus the number needed to treat to prevent 1 event was 250 in the experimental period (6 months) or 125 when normalized at one-year treatment (1 year number needed to treat]. When considering the prophylaxis gain in intermediate (risk 1-2%) or high risk subjects (patients with a probability of an event over 2%, for the presence of 1 important risk factor or multiple factors), the 1-year number needed to treat rapidly drops from about 100 to about 17. The number needed to harm for one withdrawal was 18. The number needed to treat corrected for withdrawals in order to avoid major complications rises from 125 to 132 in the general population of non-steroidal anti-inflammatory drug users; from 102 to 105 in subjects at intermediate risk, such as patients with history of cardiovascular disease; in the groups at high risk, from 26 to 27 (patients with history of peptic ulcer disease), and from 16 to 17 (patients with history of peptic ulcer disease, cardiovascular disease and aged over 65 years).

CONCLUSIONS

Patients at intermediate and high risk for complications from non-steroidal anti-inflammatory drug-induced ulcers should be considered for prophylaxis. In this group of patients, misoprostol prevention of severe complications is effective, and its clinical relevance similar to that of other preventive measures in medical practice.

Management of gastroduodenal ulcers caused by non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are a major cause of morbidity and mortality, probably resulting in the death of 1200 patients per annum in the UK. The main mechanism of toxicity involves an inhibition of prostaglandin synthesis that results in mucosal erosion as a result of the abrogation of defence mechanisms. However, acid peptic attack can deepen this initial injury. Thus, logical treatments include prostaglandin analogues as 'replacement therapy', acid suppression, enteric coating to avoid topical effects and the use of safer NSAIDs, including those that have little or no effect on gastric mucosal prostaglandin synthesis. There is less logic to the strategy of Helicobacter pylori (H. pylori) eradication, and the status of this approach is controversial. Overall, proton pump inhibitors have the best profile of efficacy and side-effects for the healing and prevention of NSAID-associated ulcers. Misoprostol is also effective and appears to be superior to proton pump inhibitors for superficial erosive injury. Early indications are that selective inhibitors of the inducible cyclooxygenase-2 enzyme have little or no effect in causing ulcers. Growing experience with these agents will probably revolutionize the management of patients with arthritic conditions. However, the increasing use of low-dose aspirin for cardiovascular prophylaxis means that gastroenterologists will have to continue to grapple with the problems of NSAID-associated ulcers for some time to come.

Prevention of chronic NSAID induced upper gastrointestinal toxicity

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are important agents in the management of arthritic and inflammatory conditions, and are among the most frequently prescribed medications in North America and Europe. However, there is overwhelming evidence linking these agents to a variety of gastrointestinal (GI) toxicities.

OBJECTIVES

To review the effectiveness of common interventions for the prevention of NSAID induced upper GI toxicity.

SEARCH STRATEGY

A literature search was conducted, according to the Cochrane methodology for identification of randomized controlled trials in electronic databases, including MEDLINE from 1966 to January 2000, Current Contents for 6 months prior to January 2000, Embase to Febuary 1999, and a search of the Cochrane Controlled Trials Register from 1973 to 1999. Recent conference proceedings were reviewed and content experts and companies were contacted.

SELECTION CRITERIA

Randomized controlled clinical trials (RCTs) of prostaglandin analogues (PA), H2-receptor antagonists (H2RA) or proton pump inhibitors (PPI) for the prevention of chronic NSAID induced upper GI toxicity were included.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data regarding population characteristics, study design, methodological quality and number of patients with endoscopic ulcers, ulcer complications, symptoms, overall drop-outs, drop outs due to symptoms. Dichotomous data was pooled using Revman V3.1. Heterogeneity was evaluated using a chi square test.

MAIN RESULTS

Thirty-three RCTs met the inclusion criteria. All doses of misoprostol significantly reduced the risk of endoscopic ulcers. Misoprostol 800 ug/day was superior to 400 ug/day for the prevention of endoscopic gastric ulcers (RR=0.18, and RR=0. 38 respectively, p=0.0055). A dose response relationship was not seen with duodenal ulcers. Misoprostol caused diarrhea at all doses, although significantly more at 800ug/day than 400ug/day (p=0.0012). Misoprostol was the only prophylactic agent documented to reduce ulcer complications. Standard doses of H2RAs were effective at reducing the risk of endoscopic duodenal (RR=0.24; 95% CI: 0.10-0. 57) but not gastric ulcers(RR=0.73; 95% CI:0.50-1.09). Both double dose H2RAs and PPIs were effective at reducing the risk of endoscopic duodenal and gastric ulcers (RR=0.44; 95% CI:0.26-0.74 and RR=0.37;95% CI;0.27-0.51 respectively for gastric ulcer), and were better tolerated than misoprostol.

REVIEWER'S CONCLUSIONS

Misoprostol, PPIs, and double dose H2RAs are effective at preventing chronic NSAID related endoscopic gastric and duodenal ulcers. Lower doses of misoprostol are less effective and are still associated with diarrhea. Only Misoprostol 800ug/day has been directly shown to reduce the risk of ulcer complications.

Preventing NSAID Toxicity to the Upper Gastrointestinal Tract

Prevention of gastrointestinal toxicity begins with the selection of an appropriate analgesic or anti-inflammatory agent. For conditions without inflammation, such as some cases of osteoarthritis, an analgesic with no risk for gastrointestinal toxicity is appropriate. Risk factors for nonsteroidal anti-inflammatory drug (NSAID)-related complications include advanced age; history of ulcer disease or gastrointestinal bleeding; concomitant corticosteroid or anticoagulant use; use of high-dose or multiple NSAIDs; and certain chronic diseases, such as cardiovascular disease. If an NSAID must be used in a patient with risk factors, the patient should receive the lowest-risk NSAID and, in most cases, co-therapy to reduce the risk for NSAID-associated ulcers and their complications. The PGE1 prostaglandin analogue misoprostol is highly efficacious for the prevention of both gastric and duodenal ulcers and has also been shown to reduce the incidence of NSAID-induced ulcer complications. Side effects, such as diarrhea, may limit patient acceptance of the drug. Acid suppression with traditional ulcer-healing doses of H2-blockers significantly reduces rates of duodenal ulcer but is ineffective in reducing gastric ulceration. More potent acid inhibition with double-dose H2-blockers reduces rates of both gastric and duodenal ulcers. Proton-pump inhibitors, such as omeprazole, have been shown to prevent gastric and duodenal ulcers with an efficacy equal to that of misoprostol. They also reduce NSAID-related dyspepsia. Specific cyclooxygenase-2 (COX-2) inhibitors are associated with a markedly reduced rate of endoscopic ulcers. Very high-risk patients who receive these agents may still require co-therapy to prevent complications or reduce dyspepsia. This protocol may be changed by the results of long-term gastrointestinal outcome studies now underway.

Agents used in the prevention and treatment of nonsteroidal anti-inflammatory drug-associated symptoms and ulcers

Coprescription of gastroprotective agents is a common practice for patients requiring nonsteroidal anti-inflammatory drug (NSAID) therapy, although there is limited evidence that some of these agents are effective. The prostaglandin analog misoprostol and the proton pump inhibitor omeprazole appear to be efficacious in decreasing NSAID-associated ulcers. Misoprostol has also been shown to decrease NSAID-associated gastrointestinal (GI) complications by 40% compared with placebo. Despite the efficacy of these drugs, their effectiveness in the general population has not yet been adequately determined with respect to reduction of symptoms and improvement in patient quality of life. Sucralfate and bismuth appear to be largely ineffective, and histamine receptor antagonists, when given at traditional ulcer-healing doses, decrease symptoms and duodenal ulcers only. The issue of outcomes research, therefore, needs to be more fully incorporated into any analysis of the effectiveness or cost-effectiveness of the widespread clinical use of such gastroprotective drugs.

Omeprazole. A review of its use in Helicobacter pylori infection, gastro-oesophageal reflux disease and peptic ulcers induced by nonsteroidal anti-inflammatory drugs

Omeprazole is a well studied proton pump inhibitor that reduces gastric acid secretion. This review examines its use in Helicobacter pylori infection, gastro-oesophageal reflux disease (GORD) with or without oesophagitis and gastrointestinal damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Optimal omeprazole regimens for anti-H. pylori therapy are those that administer the drug at a dosage of 40 mg/day (in 1 or 2 divided doses) for 7, 10 or 14 days in combination with 2 antibacterial agents. As a component of 3-drug regimens in direct comparative studies, omeprazole was at least as effective as lansoprazole, pantoprazole, bismuth compounds and ranitidine. However, a meta-analysis suggests that triple therapies with omeprazole are more effective than comparable regimens containing ranitidine, lansoprazole or bismuth. Omeprazole also appears to be successful in triple therapy regimens used in children with H. pylori infection. In patients with acute GORD with oesophagitis, omeprazole is at least as effective as lansoprazole or pantoprazole in promoting healing, and superior to ranitidine, cimetidine or cisapride in oesophagitis healing and symptom relief. Omeprazole was similar to lansoprazole and superior to ranitidine in preventing oesophagitis relapse in patients with all grades of oesophagitis, but may be superior to lansoprazole or pantoprazole in patients with more severe disease. More patients with symptomatic GORD without oesophagitis experienced symptom relief after short term treatment with omeprazole than with ranitidine, cisapride or placebo, and symptoms were more readily prevented by omeprazole than by cimetidine or placebo. Omeprazole was effective in healing and relieving symptoms of reflux oesophagitis in children with oesophagitis refractory to histamine H2 receptor antagonists. Omeprazole is superior to placebo in preventing NSAID-induced gastrointestinal damage in patients who must continue to take NSAIDs. It is also similar to misoprostol and superior to ranitidine in its ability to heal NSAID-induced peptic ulcers and erosions, and superior to misoprostol, ranitidine or placebo in its ability to prevent relapse. In long and short term studies, omeprazole was well tolerated, with diarrhoea, headache, dizziness, flatulence, abdominal pain and constipation being the most commonly reported adverse events. Usual omeprazole dosages, alone or combined with other agents, are 10 to 40 mg/day for adults and 10 to 20 mg/day for children.

CONCLUSIONS

Omeprazole is a well studied and well tolerated agent effective in adults or children as a component in regimens aimed at eradicating H. pylori infections or as monotherapy in the treatment and prophylaxis of GORD with or without oesophagitis or NSAID-induced gastrointestinal damage.

Proton pump inhibitors. Pharmacology and rationale for use in gastrointestinal disorders

Proton pump inhibitors (PPIs) are drugs which irreversibly inhibit proton pump (H+/K+ ATPase) function and are the most potent gastric acid-suppressing agents in clinical use. There is now a substantial body of evidence showing improved efficacy of PPIs over the histamine H2 receptor antagonists and other drugs in acid-related disorders. Omeprazole 20 mg/day, lansoprazole 30 mg/day, pantoprazole 40 mg/day or rabeprazole 20 mg/day for 2 to 4 weeks are more effective than standard doses of H2-receptor antagonists in healing duodenal and gastric ulcers. Patients with gastric ulcers should receive standard doses of PPIs as for duodenal ulcers but for a longer time period (4 to 8 weeks). There is no conclusive evidence to support the use of a particular PPI over another for either duodenal or gastric ulcer healing. For Helicobacter pylori-positive duodenal ulceration, a combination of a PPI and 2 antibacterials will eradicate H. pylori in over 90% of cases and significantly reduce ulcer recurrence. Patients with H. pylori-positive gastric ulcers should be managed similarly. PPIs also have efficacy advantages over ranitidine and misoprostol and are better tolerated than misoprostol in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs). In endoscopically proven gastro-oesophageal reflux disease, standard daily doses of the PPIs are more effective than H2-receptor antagonists for healing, and patients should receive a 4 to 8 week course of treatment. For severe reflux, with ulceration and/or stricture formation, a higher dose regimen (omeprazole 40 mg, lansoprazole 60 mg, pantoprazole 80 mg or rabeprazole 40 mg daily) appears to yield better healing rates. There is little evidence that PPIs lead to resolution of Barrett's oesophagus or a reduction of subsequent adenocarcinoma development, but PPIs are indicated in healing of any associated ulceration. In Zollinger-Ellison syndrome, PPIs have become the treatment of choice for the management of gastric acid hypersecretion.