Randomized trial of low-dose misoprostol and naproxen vs. nabumetone to prevent recurrent upper gastrointestinal haemorrhage in users of non-steroidal anti-inflammatory drugs

Co-prescription of gastroprotective agents and their efficacy in elderly patients taking nonsteroidal anti-inflammatory drugs: a systematic review of observational studies

BACKGROUND & AIMS

Guidelines recommend prescribing gastroprotective agents (proton pump inhibitors, misoprostol) to older patients (primarily ≥65 years old) taking nonsteroidal anti-inflammatory drugs (NSAIDs) to prevent gastrointestinal ulcers. Older individuals are underrepresented in clinical trials of these agents. We systematically reviewed evidence from observational studies on the use of gastroprotective agents in elderly patients and their ability to prevent NSAID-related ulcers in this population.

METHODS

We performed a systematic search of Embase and MEDLINE and identified 23 observational studies that focused on elderly patients and reported data on co-prescription of gastroprotective agents and NSAIDs and/or the effectiveness of the agents in preventing gastrointestinal events in NSAID users. We collected data on rates of co-prescription and NSAID-related gastrointestinal events in patients with and without gastroprotection.

RESULTS

A median of 24% (range, 10%-69%) of elderly patients taking NSAIDs received a co-prescription for gastroprotective agents; this percentage was only slightly higher in the oldest age groups. All studies of efficacy showed a positive effect of gastroprotection. However, the adjusted results were not suitable for synthesis, and the 5 studies reporting unadjusted results were too heterogeneous for meta-analysis (I(2) = 97%). The studies differed in outcomes, definitions of co-prescription, and differences in baseline risk factors between patients with and without gastroprotection. None of the studies assessed adverse effects of gastroprotective agents. The 2 cost-effectiveness studies reached opposing conclusions.

CONCLUSIONS

In a systematic review, the observational evidence for the efficacy of gastroprotective agents in preventing NSAID-associated gastrointestinal events was in agreement with results of randomized controlled trials. However, because of heterogeneity of included studies, it is not clear what the effect would be if more patients were treated, or at what age gastroprotection should be recommended. We offer suggestions to facilitate comparison with other work and address the questions of risk and benefit in relation to age.

Mechanisms, prevention and clinical implications of nonsteroidal anti-inflammatory drug-enteropathy

This article reviews the latest developments in understanding the pathogenesis, detection and treatment of small intestinal damage and bleeding caused by nonsteroidal anti-inflammatory drugs (NSAIDs). With improvements in the detection of NSAID-induced damage in the small intestine, it is now clear that this injury and the associated bleeding occurs more frequently than that occurring in the stomach and duodenum, and can also be regarded as more dangerous. However, there are no proven-effective therapies for NSAID-enteropathy, and detection remains a challenge, particularly because of the poor correlation between tissue injury and symptoms. Moreover, recent studies suggest that commonly used drugs for protecting the upper gastrointestinal tract (i.e., proton pump inhibitors) can significantly worsen NSAID-induced damage in the small intestine. The pathogenesis of NSAID-enteropathy is complex, but studies in animal models are shedding light on the key factors that contribute to ulceration and bleeding, and are providing clues to the development of effective therapies and prevention strategies. Novel NSAIDs that do not cause small intestinal damage in animal models offer hope for a solution to this serious adverse effect of one of the most widely used classes of drugs.

Prevention of NSAID-associated gastroduodenal injury in healthy volunteers-a randomized, double-blind, multicenter study comparing DA-9601 with misoprostol

In addition to inhibiting cyclooxygenase and prostaglandin, nonsteroidal anti-inflammatory drugs (NSAIDs) may cause gastroduodenal injuries due to reactive oxygen species produced by recruited inflammatory cells. DA-9601 is a novel antioxidant with anti-inflammatory and cyto-protective effects. This study was conducted to compare the efficacy and safety of DA-9601 with misoprostol for preventing NSAID-associated gastroduodenal injury. In this randomized, double-blind, multicenter, noninferiority trial we compared the extents of protection of gastric and duodenal mucosae by endoscopy after 4 weeks of treatment with DA-9601 60 mg or misoprostol 200 µg three times daily, in subjects with normal baseline endoscopic findings who received an NSAID twice daily for 4 weeks. A total of 266 subjects were randomized to treatment. At week 4, the gastric protection rates with DA-9601 and misoprostol were 85.1% and 95.2%, respectively; the difference between the groups was -10.1% (var = 0.001), which was shown to indicate noninferiority of DA-9601 compared to misoprostol. Adverse events were lower in the DA-9601 group, 56.4% (95% CI, 48.0%-64.8%) than in the misoprostol group, 69.2% (95% CI, 61.3%-77.0%) (P = 0.031). DA-9601 is not inferior to misoprostol for preventing NSAID-associated gastroduodenal injury, and superior to it with respect to treatment-related side effects.

Prevention of NSAID-related upper gastrointestinal toxicity: a meta-analysis of traditional NSAIDs with gastroprotection and COX-2 inhibitors

Background:

Traditional NSAIDs (tNSAIDs) and COX-2 inhibitors (COX-2s) are important agents for the treatment of a variety or arthritic conditions. The purpose of this study was to systematically review the effectiveness of misoprostol, H2-receptor antagonists (H2RAs), and proton pump inhibitors (PPIs) for the prevention of tNSAID related upper gastrointestinal (GI) toxicity, and to review the upper gastrointestinal (GI) safety of COX-2s.

Methods:

An extensive literature search was performed to identify randomized controlled trials (RCTs) of prophylactic agents used for the prevention of upper GI toxicity, and RCTs that assessed the GI safety of the newer COX-2s. Meta-analysis was performed in accordance with accepted techniques.

Results:

39 gastroprotection and 69 COX-2 RCTs met inclusion criteria. Misoprostol, PPIs, and double doses of H2RAs are effective at reducing the risk of both endoscopic gastric and duodenal tNSAID-induced ulcers. Standard doses of H2RAs are not effective at reducing the risk of tNSAID-induced gastric ulcers, but reduce the risk of duodenal ulcers. Misoprostol is associated with greater adverse effects than the other agents, particularly at higher doses. COX-2s are associated with fewer endoscopic ulcers and clinically important ulcer complications, and have fewer treatment withdrawals due to GI symptoms than tNSAIDS. Acetylsalicylic acid appears to diminish the benefit of COX-2s over tNSAIDs. In high risk GI patients, tNSAID with a PPI or a COX-2 alone appear to offer similar GI safety, but a strategy of a COX-2 with a PPI appears to offer the greatest GI safety.

Conclusion:

Several strategies are available to reduce the risk of upper GI toxicity with tNSAIDs. The choice between these strategies needs to consider patients’ underlying GI and cardiovascular risk.

Proton pump inhibitors for gastroduodenal damage related to nonsteroidal anti-inflammatory drugs or aspirin: twelve important questions for clinical practice

Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin are among the most commonly used medications worldwide. Their use is associated with significant gastroduodenal adverse effects, including dyspepsia, bleeding, ulcer formation, and perforation. Given their long-term use by millions of patients, there is a substantial impact at the population level of these complications. In this evidence-based review, we have endeavored to answer 12 commonly encountered questions in clinical practice that deal with the following: extent of the problem of NSAID/aspirin-induced gastroduodenal damage and its impact on public health; role of proton pump inhibitors (PPIs) in the primary prevention, healing, and secondary prevention of NSAID/aspirin-induced gastroduodenal ulceration as assessed by using endoscopic end points; role of PPIs in the prevention of adverse clinical outcomes related to NSAID/aspirin use; whether PPIs are effective in NSAID-induced dyspepsia; comparison of PPI co-therapy with selective cyclooxygenase-2 inhibitors for risk reduction of adverse clinical outcomes; role of PPIs in preventing rebleeding from aspirin +/- clopidogrel therapy in high-risk patients; identifying high-risk patients who can benefit from PPI co-therapy; the role of other gastroprotective agents for prevention of NSAID/aspirin-induced gastroduodenal damage; and the cost-effectiveness of and limitations to the use of PPIs for prevention of gastroduodenal damage related to the use of NSAIDs or aspirin. We then summarized our recommendations on the use of PPIs for the clinical management of patients using NSAIDs or aspirin.

Safety of the nonselective NSAID nabumetone : focus on gastrointestinal tolerability

Although effective in the treatment of pain associated with rheumatic conditions such as osteoarthritis and rheumatoid arthritis, long-term use of NSAIDs is primarily limited by their association with upper gastrointestinal (GI) toxicity. Adverse effects range from dyspepsia and abdominal pain to ulceration and bleeding. GI damage elicited by NSAIDs arises as the result of biochemically induced topical irritant effects and by topical and systemic pharmacological suppression of gastroprotective prostaglandins. Variation in the physicochemical properties and pharmacological profiles among the individual NSAIDs translate into inter-agent differences regarding propensity to cause adverse GI effects. Nabumetone is a nonselective NSAID that offers distinct advantages over other agents in this class with regard to GI tolerability. Its non-acidic nature and pro-drug formulation, together with the lack of biliary secretion of its active metabolite, 6-methoxy-2-naphthylacetic acid, are thought to contribute to the improved GI tolerability of this drug. In head-to-head trials with other NSAIDs, nabumetone has demonstrated significant benefits regarding the incidence of GI events and more serious perforations, ulcers and bleeds (PUBs). Pooled data from eight postmarketing, randomized, controlled trials demonstrated a lower cumulative frequency of PUBs with nabumetone (0.03%; 95% CI 0.0, 0.08) versus comparator NSAIDs (1.4%; 95% CI 0.5, 2.4). Large-scale database studies also indicate that risk of serious GI complications is lower with nabumetone than comparator NSAIDs. Limited comparative data suggest that nabumetone offers a GI tolerability profile similar to that of cyclo-oxygenase-2 selective NSAIDs (coxibs). Although adverse cardiovascular outcomes appear to be a class effect of the coxibs, conventional NSAIDs may also have the potential for causing atherothrombotic complications. However, based on available data, nabumetone does not appear to be associated with increased cardiovascular risk. Finally, there is no particular concern about the nephrotoxic and hepatotoxic potential of nabumetone. Nonetheless, the potential for adverse drug reactions remains, and hence nabumetone, as with any NSAID, should be used at the lowest dose, which is effective for each patient, and for the shortest time necessary to control symptoms.

Primer: managing NSAID-induced ulcer complications--balancing gastrointestinal and cardiovascular risks

Ulcer complications associated with the use of NSAIDs, in high-risk patients, are often caused by a failure to identify patients' risk factors, concomitant use of aspirin or multiple NSAIDs, and underutilization of gastroprotective agents. Current data suggest that cyclo-oxygenase 2 (COX2) inhibitors and some nonselective NSAIDs increase the risk of myocardial infarction. Physicians must, therefore, take into account both the gastrointestinal and the cardiovascular risks of individual patients when prescribing NSAIDs. In patients with a low cardiovascular risk, NSAIDs can be prescribed according to the level of gastrointestinal risk. Patients with a moderate gastrointestinal risk (one or two risk factors) should receive a COX2 inhibitor or an NSAID plus a PPI or misoprostol. Patients with more than two gastrointestinal risk factors or prior ulcer complications require the combination of a COX2 inhibitor and a PPI. Patients with a high cardiovascular risk (e.g. coronary heart disease or an estimated 10-year cardiovascular risk greater than 10%) should receive prophylactic aspirin and combination therapy with a PPI or misoprostol irrespective of the presence of gastrointestinal risk factors. Naproxen is the preferred NSAID because it is not associated with excess cardiovascular risk. Patients with a high cardiovascular risk and a very high gastrointestinal risk should avoid using NSAIDs or COX2 inhibitors.

Appropriate choice of proton pump inhibitor therapy in the prevention and management of NSAID-related gastrointestinal damage

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastrointestinal adverse effects, ranging from dyspepsia and peptic ulcer disease to more serious complications such as haemorrhage or perforation. NSAID-induced gastrointestinal toxicity is a significant medical problem worldwide. Misoprostol is effective in reducing NSAID-induced mucosal damage, but patient compliance is limited by poor tolerance. Histamine receptor antagonists are relatively effective against duodenal ulcers but offer no significant protection against gastric ulcers. Proton pump inhibitors (PPIs), such as pantoprazole, omeprazole and lansoprazole, have been shown to be effective in preventing the development of gastric and duodenal ulcers in high-risk patients taking NSAIDs. PPI therapy is also beneficial in healing NSAID-induced ulcers and preventing their recurrence in patients requiring ongoing NSAID therapy. PPIs have an excellent safety profile, and pantoprazole--with its low potential for drug-drug interactions--is particularly suitable for administration to elderly patients who often require concomitant treatment with other medications.

Peptic-ulcer disease

The discovery of Helicobacter pylori has greatly changed our approach to peptic ulcer disease. Bacterial, host, and environmental factors all have a role in peptic-ulcer disease. Although the prevalence of uncomplicated peptic ulcers is falling, hospital admissions for ulcer complications associated with non-steroidal anti-inflammatory drugs (NSAIDs) are rising. Evidence suggests that prescription of NSAIDs along with potent antiulcer agents and the use of highly selective cyclo-oxygenase-2 inhibitors reduce gastroduodenal ulceration. Whether these therapeutic advances will translate into clinical benefits remains to be seen. The interaction between H pylori and NSAIDs is one of the most controversial issues in peptic ulcer disease. With the fall in rates of H pylori infection, the proportion of ulcers not related to this organism and NSAIDs has risen, which will affect the management of peptic ulcer.

Prophylaxis and treatment of non-steroidal anti-inflammatory drug-induced upper gastrointestinal side-effects

The use of specific agents to heal mucosal lesions or to prevent non-steroidal anti-inflammatory drug toxicity, has focused upon two approaches: replacement of prostaglandin deficiency and inhibition of acid secretion. Acid suppression with traditional ulcer healing doses of H2-blockers is effective in healing gastric and duodenal ulcers upon discontinuation of the offending drug. In the event the non-steroidal anti-inflammatory drug must be continued, the use of H2-blockers is associated with a decrease in the healing rate. In long-term prevention studies, H2-blockers significantly reduce duodenal ulcer rates, but are ineffective in reducing gastric ulceration. More potent acid inhibition with a double-dose of H2-blockers (famotidine 80 mg daily, ranitidine 600 mg daily) may reduce the risk of gastric and duodenal ulcers. Marked acid suppression with proton pump inhibitors (omeprazole 20-40 mg, lansoprazole 30 mg daily) also appears to be very effective in healing gastric and duodenal ulcers in patients continuing the offending drug as well. An analysis of pooled data from comparative studies on omeprazole vs ranitidine, misoprostol and sucralfate shows a therapeutic advantage in favour of the proton pump inhibitor, ranging from 10 to 40%. In long-term prevention studies, omeprazole (20 mg daily) and pantoprazole (40 mg daily) have also been shown to reduce the risk of gastric and duodenal ulcers and non-steroidal anti-inflammatory drug-related dyspepsia. Current data from recent comparative studies of omeprazole (20 mg daily) vs ranitidine (150 mg daily) and misoprostol (200 microg daily) showed that, after 6 months' follow-up, the proton pump inhibitor was significantly superior to control drugs in reducing the risk both of gastric and duodenal ulcer. Misoprostol (at doses ranging from 400 microg to 800 microg/day) is an effective form of therapy for preventing non-steroidal anti-inflammatory drug-induced gastroduodenal lesions. However high-dose misoprostol only, seems adequate for the prevention of ulcer complications, mainly in high-risk non-steroidal anti-inflammatory drug users. Thus, available data are undoubtedly in favour of the proton pump inhibitors as well tolerated and effective drugs in the prophylaxis and treatment of non-steroidal anti-inflammatory drug-related mucosal lesions in the gastrointestinal tract.

Role of acid suppressants in prophylaxis of NSAID damage

Gastric acid contributes to the pathogenesis of non-steroidal anti-inflammatory drug (NSAID)-induced ulceration via several mechanisms, including conversion of superficial to deeper injury, impairment of haemostasis, and interference with ulcer healing. The suppression of acid secretion has been shown to reduce the severity of NSAID-induced mucosal damage in experimental models and clinical studies. Current evidence indicates that proton pump inhibitors (PPIs) are the preferred treatment for the healing of gastric ulcers when NSAIDs cannot be discontinued. PPIs are superior to standard-dose H(2)-receptor antagonists and equivalent to low-dose misoprostol in preventing NSAID-induced gastric ulcers. Whether there is any significant advantage of PPIs over higher doses of H(2)-receptor antagonists or misoprostol is unknown. The efficacy of PPIs is enhanced in the presence of H. Pylori infection. Omeprazole has been shown to be effective for the secondary prevention of ulcer bleeding in H. pylori -infected NSAID users. The efficacy of PPIs for the prevention of ulcer complications in H. pylori-negative NSAID users remains uncertain.

Management of nonsteroidal anti-inflammatory drug-related peptic ulcer bleeding

Nonsteroidal anti-inflammatory drugs (NSAIDs) have superseded Helicobacter pylori infection as the most important cause of peptic ulcer bleeding. Eradication of H. pylori in NSAID users will not affect ulcer healing. In high-risk patients with a history of ulcer bleeding, curing H. pylori infection alone without acid suppression has substantially reduced the risk of rebleeding caused by low-dose aspirin but not nonaspirin NSAIDs. In a study comparing the safety profile of misoprostol in combination with NSAID against nabumetone in high-risk patients with a history of ulcer bleeding, both strategies were unable to confer significant protection against the risk of rebleeding.

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.