Association of upper gastrointestinal toxicity of non-steroidal anti-inflammatory drugs with continued exposure: cohort study

Association between aspirin and upper gastrointestinal complications: systematic review of epidemiologic studies

AIMS

Because of the widespread use of aspirin for prevention of cardiovascular diseases, side-effects associated with thromboprophylactic doses are of interest. This study summarizes the relative risk (RR) for serious upper gastrointestinal complications (UGIC) associated with aspirin exposure in general and with specific aspirin doses and formulations in particular.

METHODS

After a systematic review, 17 original epidemiologic studies published between 1990 and 2001 were selected according to predefined criteria. Heterogeneity of effects was explored. Pooled estimates were calculated according to different study characteristics and patterns of aspirin use.

RESULTS

The overall relative risk of UGIC associated with aspirin use was 2.2 (95% confidence interval (CI): 2.1, 2.4) for cohort studies and nested case-control studies and 3.1 (95% CI: 2.8, 3.3) for non-nested case-control studies. Original studies found a dose-response relationship between UGIC and aspirin, although the risk was still elevated for doses lower or up to 300 mg day(-1). The summary RR was 2.6 (95% CI: 2.3, 2.9) for plain, 5.3 (95% CI: 3.0, 9.2) for buffered, and 2.4 (95% CI: 1.9, 2.9) for enteric-coated aspirin formulations.

CONCLUSIONS

Aspirin was associated with UGIC even when used at low doses or in buffered or enteric-coated formulations. The latter findings may be partially explained by channeling of susceptible patients to these formulations.

Comparative efficacy and safety of celecoxib and naproxen in the treatment of osteoarthritis of the hip

Osteoarthritis (OA) is responsible for more disability of the lower extremities in the elderly than any other disease in the US. The pain associated with OA is the primary symptom leading to disability in these patients. Current ACR guidelines recommend consideration of acetaminophen for mild-to-moderate pain and conventional non-steroidal anti-inflammatory drugs (NSAIDs) or COX-2 specific inhibitors for moderate-to-severe OA symptoms. The aim of this study was to compare the efficacy and safety of the COX-1 sparing, COX-2 specific inhibitor, celecoxib, with the conventional NSAID naproxen, and placebo, in the treatment of OA of the hip. In this multicenter, randomized, placebo-controlled trial, 1061 patients with symptomatic OA of the hip were randomized to receive celecoxib at doses of 100 mg, 200 mg, or 400 mg/day; naproxen 1000 mg/day; or placebo, for 12 weeks. Patients were evaluated using standard measures of efficacy at baseline, 2-4 days after discontinuing previous NSAID or analgesic therapy, and after 2, 6, and 12 weeks of treatment. All doses of celecoxib and naproxen significantly improved the symptoms of OA, at all time points compared with placebo. This sustained treatment effect of celecoxib was dose dependent. In terms of pain relief and improvement in functional capacity, celecoxib 200 mg/day and 400 mg/day were similarly efficacious and were comparable to naproxen. Both drugs were generally well tolerated. Celecoxib at a dose of 200 mg/day is as effective as a standard therapeutic dose of the conventional NSAID, naproxen, in reducing the pain associated with OA of the hip.

Nonsteroidal anti-inflammatory drug gastrointestinal toxicity

Toxic effects in the upper gastrointestinal tract, primarily complicated gastric and intestinal ulcers, are the most common undesirable effects of the nonsteroidal anti-inflammatory drugs. During the last several years, there have been several advances, both in the laboratory and clinically, toward reducing nonsteroidal anti-inflammatory drugs' gastrointestinal toxicity. Some of these important developments are the delineation of mechanisms of nonsteroidal anti-inflammatory drug-induced gastrointestinal toxicity, identification of groups at highest risk for development of nonsteroidal anti-inflammatory drug-induced gastrointestinal complications, recognition of co-therapies that could reduce nonsteroidal anti-inflammatory drug toxicity, and, most recently, development of classes of nonsteroidal anti-inflammatory drugs with improved gastrointestinal safety profiles. Many of these advances have occurred during the last year. This review focuses on several of the important recent observations that have improved understanding and safety of nonsteroidal anti-inflammatory drugs in the gastrointestinal tract.

Drug switching patterns among patients taking non-steroidal anti-inflammatory drugs: a retrospective cohort study of a general practitioners database in the United Kingdom

OBJECTIVE

To examine the frequency and determinants of switching between different non-steroidal anti-inflammatory drugs (NSAIDs) and the relationship with co-prescription of gastro-protective drugs (GPDs).

DESIGN

This was an analysis of 30,654 patients receiving a total of 209,140 NSAID prescriptions in the UK from 1 January 1997 to 31 December 1998 identified through the MediPlus database. Analyses examined switching, repeat, termination and GPD co-prescription rates in new and continuing takers according to age and sex.

RESULTS

Each patient received an average of 6.8 prescriptions in the year of study. Of the prescriptions 72.2% were for one of three NSAIDs, ibuprofen, diclofenac, or naproxen, and 7.2% of prescriptions were for fixed combination products of an NSAID plus a gastroprotective drug. At least 16.0% of continuing takers, and 28.5% of new takers switched to another NSAID in the review period. On average, new patients switched more frequently than continuing patients (0.39 switches/patient/year versus 0.23 switches/patient/year, p < 0.001). Switching between NSAIDs decreased with age and was less common in women (p < 0.05). Switching was associated with a 24% and 33% increased probability of GPD prescription in new and continuing takers, respectively.

DISCUSSION

The frequency of switching, and of GPD co-prescription at switching, suggest that dissatisfaction with NSAIDs is frequent, and that gastrointestinal intolerance is a common feature of this dissatisfaction.

Epidemiology of NSAID-related gastroduodenal mucosal injury

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the agents most frequently used against musculoskeletal and rheumatic disorders throughout the world. The gastroduodenal adverse effects include dyspepsia without endoscopically proven damage, asymptomatic endoscopic lesions of submucosal haemorrhage, erosions and ulcers, and-most important-ulcer complications. Established risk factors for NSAID-associated ulcer complications include patient-specific factors such as advanced age, female gender, a history of peptic ulcer, and drug-specific factors such as the use of non-selective NSAIDs (type, dose, duration, multiple use) and concomitant anticoagulant drugs or corticosteroids. Probable risk factors comprise Helicobacter pylori infection and heavy consumption of alcohol, whereas use of selective serotonin re-uptake inhibitors, smoking and a number of other factors have also been proposed to contribute. Knowledge of absolute risk estimates is important for clinical decision making. The aim of this chapter is to summarize the epidemiological data related to the broad spectrum of iatrogenic gastroduodenal mucosal injury.

Record-linkage methodology for prescribing research

Record-linkage refers to the linking together of data relating to the same individual from separate source files. In this paper, we discuss ways in which the technique can enhance observational prescribing research in large populations. We draw upon the work of the Medicines Monitoring Unit (MEMO), University of Dundee, to illustrate its contribution to prescribing research.

Incidence of clinically manifest ulcers and their complications in patients with rheumatoid arthritis

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are often prescribed in patients with rheumatoid arthritis (RA). Because of its frequency and severity, NSAID gastropathy is the most important side effect. The clinical spectrum of NSAID gastropathy includes gastrointestinal complaints, ulcers and their complications. To reduce NSAID gastropathy, rheumatologists in greater Amsterdam decided in January 1997 that prophylactic agents should be prescribed for patients with RA at high risk for NSAID gastropathy, defined as age 60 or older or a history of gastrointestinal (GI) ulcers, or both.

OBJECTIVE

To determine the incidence of clinically manifest ulcers and their complications in patients with RA at high risk for NSAID gastropathy during a period in which prophylaxis was recommended. Published reports show that the incidence of clinically manifest ulcers and their complications varies from 1.3% to 5%.

PATIENTS AND METHODS

Within one year, three questionnaires were sent to all outpatients with RA of our clinic (n=2680). The patients were asked if they had had a gastroscopy and/or complication of an ulcer in the preceding months. When a GI event (ulcer or complication) had occurred an analysis was carried out to determine whether the event was possibly related to a compliance failure or a policy failure-for example, no prophylaxis prescribed when it was recommended.

RESULTS

The response rate for the three questionnaires was 88%, 76%, and 77%, respectively. All three questionnaires were returned by 1856 patients; NSAIDs were used in 1246 (67%) of them. Of the NSAID users 731 (59%) were in the high risk group. Clinically manifest ulcers occurred in seven high risk NSAID users (four gastric ulcers, two duodenal ulcers, and in one patient both types of ulcer). Complications of ulcers were diagnosed in eight (other) patients: seven (upper) GI bleedings and one perforation. Thus the incidence during one year of clinically manifest ulcers in the high risk group was 1.0% and of complications of ulcers 1.1%, together 2.1%. In the group of 15 patients with GI events, only one patient had not taken the adequately prescribed gastroprotective drugs (compliance failure). Misguidedly, gastroprotective drugs were not prescribed in seven patients (policy failure), but in the remaining seven patients gastroprotective drugs were adequately prescribed and used.

CONCLUSION

The incidence of clinically manifest ulcers and of complications of ulcers in patients with RA at high risk for NSAID gastropathy is relatively low, and might be related to our strategy to prescribe prophylactic agents in these patients.

Preventing gastrointestinal complications of NSAIDs. Risk factors, recent advances, and latest strategies

In the United States, gastrointestinal complications induced by nonsteroidal anti-inflammatory drugs (NSAIDs) cause more than 100,000 hospitalizations and an estimated 16,500 deaths annually. Because serious gastrointestinal events can occur without warning, prevention measures must not rely on warning signs alone. This article discusses the epidemiology of NSAID-induced toxic episodes, reviews the risk factors for these occurrences, and offers strategies for minimizing the risk among long-term NSAID users.

Treatment of elderly patients with nabumetone or diclofenac: gastrointestinal safety profile

GOALS

To evaluate the efficacy and gastrointestinal safety of nabumetone and diclofenac in the treatment of elderly patients with osteoarthritis, participating in a 3-month efficacy trial.

BACKGROUND

Elderly patients have an elevated risk for developing gastrointestinal complications with chronic use of nonsteroidal anti-inflammatory drugs.

STUDY

This was a randomized, double-blind, parallel-group, multicenter study with a 3-to 14-day placebo washout period and a 12-week active treatment phase. Patients 65 years or older with moderate-to-severe osteoarthritis of the knee or hip were randomized to receive 1,000 to 2,000 mg/d of nabumetone or 100 to 150 mg/d of diclofenac. The primary efficacy parameters were the percent of patients improved using a Patients' and Physicians' Global Assessment at endpoint. Gastrointestinal safety was assessed by the incidence of gastrointestinal symptoms and adverse events.

RESULTS

Three hundred thirty-five patients (mean age = 72 years) with active osteoarthritis were enrolled. There were no statistically significant differences between the two treatment groups in any of the primary efficacy variables. However, differences between the groups were apparent in the frequency of adverse gastrointestinal events. Two patients in the diclofenac group had evidence of gastrointestinal bleeding and/or ulcer compared with none in the nabumetone group. In addition, significantly more (p < 0.05) patients (4%) receiving diclofenac had alanine transaminase values more than twice the upper limit of normal at endpoint compared with patients receiving nabumetone (0%).

CONCLUSIONS

Nabumetone was as effective as diclofenac in the treatment of elderly patients with moderate-to-severe osteoarthritis. However, the gastrointestinal safety profile of nabumetone was superior to that of diclofenac with respect to elevation of liver enzymes.

Is non-Helicobacter pylori, non-NSAID peptic ulcer a common cause of upper GI bleeding? A prospective study of 977 patients

BACKGROUND

Non-Helicobacter pylori, non-NSAID ulcer is relatively common in Western countries. Whether it is a significant problem in the Orient is unclear. The aim of this study was to investigate the incidence of non-H pylori, non-NSAID ulcers presenting with GI bleeding.

METHODS

A prospective study was done of 1675 consecutive patients presenting with upper GI bleeding over a period of 12 months. Upper endoscopy was performed with biopsy specimens taken from the antrum and body of the stomach for a biopsy urease test (BUT) and histology for detection of H pylori. Exposure to nonsteroidal anti-inflammatory drugs (NSAID) or aspirin within 4 weeks of hospitalization was carefully scrutinized. A 6-week course of treatment with an H2-receptor antagonist was prescribed for patients who did not use an NSAID and had a negative BUT result. Follow-up endoscopy was performed to confirm H pylori status with a BUT and histology. Positive histology at either initial or follow-up endoscopy was used as the standard for diagnosing H pylori infection.

RESULTS

Among 977 patients who were found to have ulcer bleeding, 434 (44%) had exposure to aspirin or an NSAID. Of the 543 non-NSAID users, 431 (79.4%) had a positive BUT and 112 (20.6%) were BUT negative on initial endoscopy. Eighty-nine of 112 patients who were NSAID negative, BUT negative returned for follow-up endoscopy. Forty-nine of 89 (55.1%) were found to have a positive BUT and positive histology at follow-up endoscopy. Only 40 of 977 (4.1%) patients admitted with ulcer bleeding were confirmed to have non-H pylori, non-NSAID ulcers.

CONCLUSIONS

Non-H pylori, non-NSAID bleeding ulcer is uncommon. A negative BUT is unreliable for exclusion of H pylori infection during the acute phase of ulcer bleeding.

Reduced incidence of gastroduodenal ulcers with celecoxib, a novel cyclooxygenase-2 inhibitor, compared to naproxen in patients with arthritis

OBJECTIVE

Nonsteroidal anti-inflammatory drugs (NSAIDs) block prostaglandin production by inhibiting cyclooxygenase (COX); they are believed to cause gastroduodenal damage by inhibiting the COX-1 isoform and to have analgesic and anti-inflammatory effects by inhibiting the COX-2 isoform. As compared to conventional NSAIDs, celecoxib, a COX-2 specific inhibitor, has been shown in previous single posttreatment endoscopy studies to be associated with lower gastroduodenal ulcer rates. In response to concerns that such studies may under-represent ulceration rates, the present serial endoscopy study was designed to compare cumulative gastroduodenal ulcer rates associated with the use of celecoxib to those of naproxen, a conventional NSAID.

METHODS

In this double-blind, parallel-group, multicenter study, 537 patients with osteoarthritis (OA) or rheumatoid arthritis (RA) were randomized to treatment with celecoxib 200 mg b.i.d. (n = 270) or naproxen 500 mg b.i.d. (n = 267) for 12 wk. Gastroduodenal damage was determined from esophagogastroduodenoscopy after 4, 8, and 12 wk of therapy. Arthritis efficacy was evaluated with Patient's and Physician's Global Assessments.

RESULTS

Gastroduodenal ulcer rates after celecoxib and naproxen treatment were 4% versus 19% in the 0-4 wk interval (p < 0.001), 2% versus 14% in the 4-8 wk interval (p < 0.001), and 2% versus 10% in the 8-12 wk interval (p < 0.001), respectively. After 12 wk of treatment, the cumulative incidence of gastroduodenal ulcers was 9% with celecoxib and 41% with naproxen. In the celecoxib group, gastroduodenal ulcers were significantly associated with Helicobacter pylori status (p < 0.05), concurrent aspirin usage (p = 0.001), and a history of ulcer (p = 0.010), but not with disease type (OA/RA), age, gender, other relevant medical histories, or concurrent corticosteroid or disease-modifying antirheumatic drugs usage (p > 0.05). Celecoxib produced a significantly lower incidence rate of both gastric (p < 0.001) and duodenal (p < 0.030) ulcers. The two agents produced similar improvements in Patient's and Physician's Global Assessments of arthritis efficacy. The incidence of adverse events and withdrawal rates did not differ significantly between treatments.

CONCLUSIONS

As compared to naproxen (500 mg b.i.d.), use of celecoxib (200 mg b.i.d.), a COX-2 specific agent, at the recommended RA dose and twice the most frequently prescribed OA dose, was associated with lower rates of gastric, duodenal, and gastroduodenal ulcers but had comparable efficacy, in patients with OA and RA.

Selective inhibition of COX-2 in humans is associated with less gastrointestinal injury: a comparison of nimesulide and naproxen

BACKGROUND

Selective inhibitors of cyclooxygenase (COX)-2 may provoke less gastric damage and platelet inhibition than conventional non-steroidal anti-inflammatory drugs.

AIMS

We compared the biochemical and gastrointestinal effects of nimesulide, a potent and selective COX-2 inhibitor, with naproxen which exhibits no selectivity.

SUBJECTS

Thirty six healthy volunteers were randomised to nimesulide 100 mg or naproxen 500 mg twice daily for two weeks in a double blind, crossover study with a washout between treatments.

METHODS

Gastrointestinal side effects were assessed by endoscopy, and by estimation of small intestinal absorption-permeability and inflammation. Comparisons were made between variables at the end of each treatment phase.

RESULTS

Nimesulide caused significantly less gastric injury using the modified Lanza score (p<0.001) as well as reduced duodenum injury (p=0.039). Nimesulide had lower visual analogue scores (VAS) for haemorrhage and erosive lesions in the stomach (p<0.001) and for mucosal injection in the duodenum (p=0.039). Naproxen increased excretion of calprotectin, a marker of intestinal inflammation (5.5 (1.2) to 12.1 (2.1) mg/l) while nimesulide had no effect (treatment difference p=0.03). Naproxen abolished platelet aggregation to arachidonic acid and suppressed serum thromboxane B(2) (TXB(2)) by 98%, indices of COX-1 activity. In contrast, nimesulide had no significant effect on platelet aggregation, although it reduced serum TXB(2) by 29%. Production of prostaglandin E(2) and prostacyclin by gastric biopsies, also COX-1 dependent, was inhibited by naproxen, but not by nimesulide. COX-2 activity, determined as endotoxin induced prostaglandin E(2) formation in plasma, was markedly suppressed by both treatments.

INTERPRETATION

Nimesulide has preferential selectivity for COX-2 over COX-1 in vivo at full therapeutic doses and induces less gastrointestinal damage than that seen with naproxen in the short term.

The multiple propensity score for analysis of dose-response relationships in drug safety studies

In order to detect adverse drug reactions, large observational drug safety studies are necessary as randomized clinical trials rarely have enough power. However, in order to obtain reliable results the issue of confounding, especially confounding by indication, should be addressed. We proposed a multiple propensity score, which is an extension of the propensity score, to reduce the bias in a dose-response analysis in a drug safety study. The multiple propensity score has similar properties to the propensity score in Rosenbaum and Rubin.(1) Using the propensity score for bias reduction of the risk ratio was considered. We used the multiple propensity score in a study of the dose-response relationship between diclofenac prescriptions and hospitalization for gastrointestinal bleeding and perforation using a record linkage database. We found that the unadjusted risk ratios were biased downwards due to confounders and that this bias was reduced by using stratification based on the multiple propensity score.

Cyclooxygenase inhibitors--current status and future prospects

Prostaglandins are formed from arachidonic acid by the action of cyclooxygenase and subsequent downstream synthetases. Two closely related forms of the cyclooxygenase have been identified which are now known as COX-1 and COX-2. Both isoenzymes transform arachidonic acid to prostaglandins, but differ in their distribution and their physiological roles. Meanwhile, the responsible genes and their regulation have been clarified. COX-1, the pre-dominantly constitutive form of the enzyme, is expressed throughout the body and performs a number of homeostatic functions such as maintaining normal gastric mucosa and influencing renal blood flow and platelet aggregation. In contrast, the inducible form is expressed in response to inflammatory and other physiological stimuli and growth factors, and is involved in the production of the prostaglandins that mediate pain and support the inflammatory process. All the classic NSAIDs inhibit both COX-1 and COX-2 at standard anti-inflammatory doses. The beneficial anti-inflammatory and analgesic effects are based on the inhibition of COX-2, but the gastrointestinal toxicity and the mild bleeding diathesis are a result of the concurrent inhibition of COX-1. Agents that inhibit COX-2 while sparing COX-1 represent a new attractive therapeutic development and could represent a major advance in the treatment of rheumatoid arthritis and osteoarthritis. Apart from its involvement in inflammatory processes, COX-2 seems to play a role in angiogenesis, colon cancer and Alzheimer's disease, based on the fact that it is expressed during these diseases. The benefits of specific and selective COX-2 inhibitors are currently under discussion and offer a new perspective for a further use of COX-2 inhibitors.

Approaches to nonsteroidal anti-inflammatory drug use in the high-risk patient

Nonsteroidal anti-inflammatory drugs (NSAIDs) are probably the most common cause of gastroduodenal injury in the United States today. Approximately half of patients who regularly take NSAIDs have gastric erosions, and 15%-30% have ulcers when they are examined endoscopically. However, the incidence of clinical gastrointestinal (GI) events caused by NSAIDs is much lower. Clinical upper GI events may occur in 3%-4.5% of patients taking NSAIDs, and serious complicated events develop in approximately 1.5%. However, the risk varies widely in relationship to clinical features such as history of ulcers or GI events, age, concomitant anticoagulant or steroid use, and NSAID dose. This review discusses the risks of clinical GI disease in NSAID users, the predictors of increased risk, and strategies for prevention of NSAID-associated GI disease.

Economic evaluation of celecoxib, a new cyclo-oxygenase 2 specific inhibitor, in Switzerland

OBJECTIVE

The aim of this study was to predict the cost effectiveness of celecoxib, a cyclo-oxygenase 2 (COX-2) specific inhibitor, in the treatment of arthritis patients in Switzerland.

METHODS

We applied a decision analytical model to compare the effects of 6 months' treatment with the following: (i) celecoxib; (ii) nonsteroidal anti-inflammatory drug (NSAID) alone; NSAID protected with (iii) proton pump inhibitor (PPI), (iv) histamine H2 receptor antagonist (H2RA), or (v) misoprostol; and (vi) diclofenac/misoprostol. Treatment costs included drug acquisition and the management of gastrointestinal (GI) adverse effects, classified as GI discomfort, symptomatic ulcer, anaemia and serious GI events (requiring hospitalisation). Probabilities were derived from celecoxib clinical trials and the literature. Drug utilisation patterns and treatment costs reflecting Swiss practice were obtained from local sources. Analysis was from the public health insurers' perspective. A range of sensitivity analyses was performed.

RESULTS

For the base case of patients at typical risk (0.56% per 6 months) of serious GI events, the total expected costs of 6 months' treatment were as follows: celecoxib 435 Swiss francs (SwF); NSAID alone SwF510; diclofenac/misoprostol SwF522; and other protected NSAID regimens between SwF1034 and SwF1415. Celecoxib remained the lowest costing treatment over all categories of GI risk. Celecoxib generated 115 expected adverse events per 1000 patients per 6 months, followed by NSAID + PPI (119), NSAID + H2RA (154), NSAID + misoprostol (202), diclofenac/misoprostol (203), and NSAID alone (220), again for the base case. The cost per adverse event averted for celecoxib compared with NSAIDs alone was estimated in a stochastic version of the model using Monte Carlo simulation. In 95% of 500 iterations, celecoxib was predicted to save both costs and adverse events, thus dominating NSAIDs alone; the maximum cost per adverse event averted was SwF440.

CONCLUSIONS

Celecoxib is predicted to be the most cost effective of the treatments considered for managing arthritis patients in Switzerland. A policy of switching patients from NSAIDs to celecoxib is predicted to be cost saving for public health insurers, while reducing the burden of iatrogenic GI side effects. Greater cost savings would be realised when patients are switched from NSAIDs used with gastroprotective agents. Models such as this can provide a useful but simplified view of treatment outcomes and predicted results require prospective validation in clinical practice.

Cox-2-specific inhibitors: definition of a new therapeutic concept

Nonsteroidal anti-inflammatory drugs have been a mainstay in the treatment of inflammatory diseases such as rheumatoid arthritis. However, these agents can result in severe and occasionally life-threatening adverse effects that can limit therapeutic benefit. Progress toward safer anti-inflammatory therapy was aided by the discovery that cyclooxygenase (COX) exists as two isozymes, COX-1 and COX-2. Both isozymes form prostaglandins that support physiologic functions; however, the formation of proinflammatory prostaglandins is catalyzed by COX-2. Inhibition of COX-2 accounts for the anti-inflammatory and analgesic action of NSAIDs; however, concurrent inhibition of COX-1 inhibits prostaglandin-dependent mechanisms such as gastroduodenal mucosal defense and platelet aggregation. This inhibition is the basis of the gastrointestinal toxicity and bleeding characteristic of these drugs. These findings led to the hypothesis that agents that selectively inhibit COX-2 would possess anti-inflammatory and analgesic action but would spare COX-1, thereby avoiding adverse effects in the gastrointestinal tract and platelets. Selective COX-2 inhibitors are now available. The novelty of these agents has raised questions in the medical community as to what constitutes selectivity for COX-2. This review outlines the criteria that must be met to characterize a compound as COX-2-specific. Clinical evidence of clear improvement in gastrointestinal tolerability and safety must be demonstrated in addition to complementary evidence of COX-2 selectivity obtained from enzyme, biochemical, and clinical pharmacology evaluations.

A framework for evaluating the clinical consequences of initial therapy with NSAIDs, NSAIDs plus gastroprotective agents, or celecoxib in the treatment of arthritis

OBJECTIVE

The purpose of this study is to provide a framework for estimating the economic efficiency of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), concomitant gastroprotective agents (GPAs) to reduce the risk of NSAID toxicity, and celecoxib, a specific cyclo-oxygenase-2 inhibitor. Concomitant GPA therapies considered include one of the following: proton pump inhibitors (PPIs) plus NSAIDs, histamine H2 receptor antagonists (H2RAs) plus NSAIDs, misoprostol plus NSAIDs, and a single tablet formulation of diclofenac/misoprostol.

DESIGN

The study employs a decision-tree framework to establish probabilities of upper gastrointestinal (GI) adverse events occurring over a 6-month time frame. Celecoxib clinical trial data are used to establish probabilities of upper GI events for celecoxib and NSAIDs, and published literature is used to predict upper GI events for the other concomitant therapies. Upper GI adverse events included in the decision-tree are as follows: GI discomfort, symptomatic ulcer, serious GI complications (with and without death), and anaemia with occult bleeding.

MAIN OUTCOME MEASURES AND RESULTS

Clinical probabilities indicate celecoxib has significant tolerability and safety advantages compared with nonselective NSAIDs. Celecoxib also reduces the risk of GI adverse events to a similar or superior degree when compared with reductions observed with NSAIDs with concomitant GPAs.

CONCLUSION

Use of celecoxib is expected to significantly reduce the economic costs of GI toxicity and its associated morbidity.

Iatrogenic cost factors incorporating mild and moderate adverse events in the economic comparison of aceclofenac and other NSAIDs

OBJECTIVE

To perform a modelled economic analysis of the efficacy and tolerability of aceclofenac in comparison with those of other nonsteroidal antiinflammatory drugs (NSAIDs) used in the treatment of common arthritic disorders including osteoarthritis, rheumatoid arthritis and ankylosing spondylitis.

DESIGN

A decision analytical model was constructed to represent the clinical and economic consequences of NSAID treatment. Probabilities of noncompliance, lack of efficacy and incidence of adverse events were obtained from comparative randomised double-blind clinical trials. Local unit treatment costs were used and an expert panel was convened to estimate resource use. Both classical foldback analysis and bootstrap methods were used to compute point estimates and 95% confidence limits of costs for NSAID treatment.

PATIENTS AND INTERVENTIONS

Data were obtained from 12 randomised double-blind clinical trials included in an earlier meta-analysis.

MAIN OUTCOME MEASURES

Total costs to the healthcare provider, including NSAID treatment costs (drug acquisition costs and physician visits for prescription) and iatrogenic costs (substitution treatment costs for patients not achieving clinical efficacy and costs of medical visits, treatment, diagnostic tests and hospital stays associated with adverse events) and the iatrogenic cost factor (ICF) were used as the primary outcome measures.

RESULTS

Means and 95% confidence intervals revealed no statistically significant differences in total costs between aceclofenac and other NSAIDs, with the exception of piroxicam, despite substantial differences in drug acquisition costs. The ICF for aceclofenac was lower than that for all other comparators, and differences in ICF between aceclofenac 200 mg/day and diclofenac 150 mg/day, indomethacin 100 mg/day, naproxen 1000 mg/day, tenoxicam 20 mg/day or ketoprofen 150 mg/day were statistically significant.

CONCLUSION

These results show that the comparative overall costs of NSAIDs bears little relation to drug acquisition cost, and that the ICF is one of the most important determinants of overall costs.

An epidemiological approach to assess the economic burden of NSAID-induced gastrointestinal events in The Netherlands

OBJECTIVE

To use the population attributable risk (PAR) to estimate the treatment costs resulting from nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) morbidity.

DESIGN

Two case-control studies with the following outcomes: (i) the start of therapy with gastroprotective agents (GPAs) and (ii) hospitalisations for GI events.

SETTING

Community-dwelling inhabitants of defined areas in The Netherlands covering the period 1989 to 1998. All analyses were performed from the perspective of a third-party payer.

METHODS

Risk and exposure data were obtained from the Dutch PHARMO system, a population-based register of drug-dispensing records and hospital records. The PAR was estimated based on stratum-specific prevalence estimates of NSAID use and the corresponding odds ratios (ORs) obtained from the case-control studies. Cost data were obtained from Dutch national hospital discharge records and tariffs. Annual treatment costs of NSAID-induced GI events were calculated based on the PAR in the sample population and extrapolated to the total population using national demographic data.

RESULTS

The adjusted ORs for starting GPA use and hospitalisation for GI events were 6.6 [95% confidence interval (CI): 5.5 to 7.8] and 5.0 (95% CI: 4.0 to 6.2), respectively, in NSAID users compared with controls. Variation of OR with age among NSAID users suggested that prevention of GI events is most efficient among the elderly. The total annual cost (1998 values) of GPA use and hospitalisations for GI events attributable to the use of NSAIDs was 59 million euro (EUR) [95% CI: EUR38.5 million to EUR98 million]. More than 65% of these NSAID-induced costs, EUR38 million, can be attributed to long term users of NSAIDs, representing only 9.3% of all users of NSAIDs.

CONCLUSIONS

The PAR can be used to estimate the costs of drug-induced morbidity and changes in costs resulting from substitutions with other drugs. For each EUR1.00 spent on NSAIDs, an additional EUR0.68 (excluding costs for prophylactic treatment) can be added for the treatment of GI adverse events.

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.

Risk of upper gastrointestinal bleeding associated with use of low-dose aspirin

OBJECTIVE

Aspirin products are known to cause irritation and injury to the gastric mucosa. We examined the risk of hospitalization for upper gastrointestinal bleeding with use of low-dose aspirin.

METHODS

This was a cohort study based on record linkage between a population-based prescription database and a hospital discharge registry in North Jutland County, Denmark, from January 1, 1991, to December 31, 1995. Incidence rates of upper gastrointestinal bleeding in 27,694 users of low-dose aspirin were compared with the incidence rates in the general population in the county.

RESULTS

A total of 207 exclusive users of low-dose aspirin experienced a first episode of upper gastrointestinal bleeding with admission to the hospital during the study period. The standardized incidence rate ratio was 2.6 (95% confidence interval, 2.2-2.9), 2.3 in women and 2.8 in men. The standardized incidence rate ratio for combined use of low-dose aspirin and other nonsteroidal anti-inflammatory drugs was 5.6 (95% confidence interval, 4.4-7.0). The risk was similar among users of noncoated low-dose aspirin (standardized incidence rate ratio, 2.6; 95% confidence interval, 1.8-3.5) and coated low-dose aspirin (standardized incidence rate ratio, 2.6; 95% confidence interval, 2.2-3.0).

CONCLUSIONS

Use of low-dose aspirin was associated with an increased risk of upper gastrointestinal bleeding, with still higher risks when combined with other nonsteroidal anti-inflammatory drugs. Enteric coating did not seem to reduce the risk. The findings from this observational study raise the possibility that prophylactic use of low-dose aspirin may convey an increased risk of gastrointestinal bleeding, which may offset some of its benefits.

Reduced risk of upper gastrointestinal ulcer complications with celecoxib, a novel COX-2 inhibitor

OBJECTIVE

The aim of this study was to assess the rate of upper gastrointestinal (UGI) ulcer complications (bleeding, perforation, or gastric outlet obstruction) associated with celecoxib, a specific COX-2 inhibitor, compared with the rate associated with nonspecific, nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS

A pooled analysis was conducted of 14 multicenter, double-blind, randomized, controlled trials (RCTs) and a separate analysis of one long-term open label trial that assessed the efficacy and safety of celecoxib for symptomatic treatment of arthritis. The RCTs enrolled 11,008 patients with osteoarthritis or rheumatoid arthritis treated for 2-24 wk; the long-term open label trial enrolled 5,155 patients receiving celecoxib for a maximum of 2 yr. In the RCTs, patients were randomly assigned to receive placebo (n = 1,864; 208 patient-years), celecoxib 25-400 mg b.i.d. (n = 6,376; 1,020 patient-years), or a comparator NSAID (n = 2,768; 535 patient-years); NSAIDs were naproxen 500 mg b.i.d., diclofenac 50 or 75 mg b.i.d., or ibuprofen 800 mg t.i.d.). In the long-term, open-label trial, patients received celecoxib 100-400 mg b.i.d. for up to 2 yr (n = 5,155; 5,002 patient-years). The principal outcome measure of this analysis was development of a UGI ulcer complication, which was prospectively defined as bleeding, perforation, or gastric outlet obstruction. Ulcer complications were assessed and adjudicated by persons blinded to the patient's treatment assignment or the study in which the patient participated.

RESULTS

In the RCTs, UGI ulcer complications occurred in no placebo patients (0 of 1,864 patients), in 2 of 6,376 celecoxib patients (0.03%), and in 9 of 2,768 patients receiving an NSAID (0.33%), corresponding to annual incidences of 0.20% for celecoxib (p > 0.05 vs placebo) and 1.68% for NSAIDs (p = 0.002 vs celecoxib and placebo). In the long-term open-label trial, nine UGI ulcer complications occurred, for an incidence of 0.17% and an annualized incidence of 0.18%.

CONCLUSIONS

The incidence of UGI ulcer complications associated with celecoxib was 8-fold lower than with nonspecific NSAIDs. The incidence of ulcer complications observed in celecoxib-treated patients was similar to that in patients receiving placebo in the RCTs, and to that in non-NSAID users reported in the literature.

The incidence of adverse events and risk factors for upper gastrointestinal disorders associated with meloxicam use amongst 19,087 patients in general practice in England: cohort study

AIMS

Meloxicam is a novel nonsteroidal anti-inflammatory drug (NSAID) which may be associated with fewer adverse upper gastrointestinal events than other NSAIDs because it preferentially inhibits the inducible enzyme cyclo-oxygenase-2 relative to the constitutive isoform, cyclo-oxygenase-1. The aims of the study were to: determine the rate of adverse events associated with meloxicam in general practice, stratify these rates by selected risk factors, and to identify signals of previously unsuspected adverse events associated with meloxicam.

METHODS

As part of the national prescription-event monitoring pharmacovigilance system for newly launched drugs in general practice, all patients prescribed meloxicam in England between December 1996 and March 1997 were identified by the central Prescription Pricing Authority. We sent short questionnaires to all prescribers asking about adverse events experienced within 6 months of the first prescription.

RESULTS

There were 19 087 patients in the study. The rate of dyspepsia during the first month of exposure was 28.3 per 1000 patient-months. There were 33 reports of upper gastrointestinal haemorrhage during treatment (rate: 0.4 per 1000 months). A history of gastrointestinal disorder in the previous year was associated with an increased rate of dyspepsia (rate ratio: 3.0; 95% confidence interval: 2.6, 3.4), abdominal pain (2.1; 1.6, 2.6), and peptic ulcer (4.0; 1.4, 13.2). Prior NSAID use was associated with a 20-30% decrease in the rate of dyspepsia and abdominal pain in patients starting meloxicam, while patients prescribed concomitant gastroprotective agents had a two to three-fold increased rate of dyspepsia, abdominal pain and peptic ulceration. Other rare events were thrombocytopenia (n = 2); interstitial nephritis (n = 1) and idiosyncratic liver abnormalities (n = 1).

CONCLUSIONS

In the absence of gastro-intestinal risk factors the incidence of gastro-intestinal disturbance was low. Such risk factors should be carefully reviewed prior to prescribing meloxicam.

Colostrum and milk-derived peptide growth factors for the treatment of gastrointestinal disorders

Colostrum is the specific first diet of mammalian neonates and is rich in immunoglobulins, antimicrobial peptides, and growth factors. In this article we review some of these constituents of human and bovine colostrum in comparison with those of mature milk. Recent studies suggest that colostral fractions, or individual peptides present in colostrum, might be useful for the treatment of a wide variety of gastrointestinal conditions, including inflammatory bowel disease, nonsteroidal antiinflammatory drug-induced gut injury, and chemotherapy-induced mucositis. We therefore discuss the therapeutic possibilities of using whole colostrum, or individual peptides present in colostrum, for the treatment of various gastrointestinal diseases and the relative merits of the 2 approaches.

An evidence-based approach to the management of uninvestigated dyspepsia in the era of Helicobacter pylori. Canadian Dyspepsia Working Group

OBJECTIVES

To provide Canadian primary care physicians with an evidence-based clinical management tool, including diagnostic and treatment recommendations, for patients who present with uninvestigated dyspepsia.

RECOMMENDATIONS

The management tool has 5 key decision steps addressing the following: (1) evidence that symptoms originate in the upper gastrointestinal tract, (2) presence of alarm features, (3) use of nonsteroidal anti-inflammatory drugs (NSAIDs), (4) dominant reflux symptoms and (5) evidence of Helicobacter pylori infection. All patients over 50 years of age who present with new-onset dyspepsia and patients who present with alarm features should receive prompt investigation, preferably by endoscopy. The management options for patients with uninvestigated dyspepsia who use NSAIDs regularly are: (1) to stop NSAID therapy and assess symptomatic response, (2) to treat with NSAID prophylaxis if NSAID therapy cannot be stopped or (3) to refer for investigation. Gastroesophageal reflux disease can be diagnosed clinically if the patient's dominant symptoms are heartburn or acid regurgitation, or both; these patients should be treated with acid suppressive therapy. The remaining patients should be tested for H. pylori infection, and those with a positive result should be treated with H. pylori-eradication therapy. Those with a negative result should have their symptoms treated with optimal antisecretory therapy or a prokinetic agent. VALIDATION AND EVIDENCE: Evidence for resolution of the dyspepsia symptoms was the main outcome measure. Supporting evidence for the 5 steps in the management tool and the recommendations for treatment were graded according to the strength of the evidence and were endorsed by consensus of committee members. If no randomized controlled clinical trials were available, the recommendations were based on the best available evidence.

LITERATURE REVIEW

Evidence was obtained from MEDLINE searches for pertinent articles published from 1966 to October 1999. The searches focused on dyspepsia, diagnosis and treatment. Additional articles were retrieved through a manual search of bibliographies and abstracts from international gastroenterology conferences.

Safety and efficacy of nabumetone in osteoarthritis: emphasis on gastrointestinal safety

AIM

To compare the efficacy and gastrointestinal (GI) safety of nabumetone with two comparator non-steroidal anti-inflammatory drugs (NSAIDs), diclofenac SR and piroxicam.

METHODS

Two randomized, double-blind, multicentre, parallel group trials were carried out in patients with moderate to severe osteoarthritis of the hip or knee. During the 6 month treatment phase, the safety and efficacy of nabumetone (1500-2000 mg/day) was compared to diclofenac SR (100 mg/day) or piroxicam (20-30 mg/day). GI safety was evaluated by reviewing all adverse events reported during the trials and presenting all cases of ulcers (complicated and uncomplicated), as well as other bleeding events that may have been associated with NSAID administration.

RESULTS

Most of the efficacy parameters showed no significant differences between the NSAIDs, although diclofenac SR was significantly better than nabumetone in one of 18 efficacy parameters. Nabumetone-treated patients experienced significantly fewer ulcer and bleeding events compared to patients treated with the comparator NSAIDs [1.1% (4/348) vs. 4.3% (15/346), P = 0.01]. Bleeding events, including outright upper or lower GI bleeding or a significant decline in haemoglobin, occurred in significantly fewer patients treated with nabumetone than with the comparator NSAIDs [1.1% (4/348) vs. 3.5% (12/346), P < 0.05]. More importantly, complications associated with either ulcers (perforation) or bleeding (leading to hospitalization or withdrawal) occurred in significantly fewer patients receiving nabumetone [0% (0/348)] than with comparator NSAIDs [1.4% (5/346), (P < 0.05)].

CONCLUSION

The results suggest that nabumetone was similar in efficacy by most criteria to diclofenac SR and piroxicam in relieving the symptoms of osteoarthritis; however, nabumetone's GI safety profile was generally superior to that of both comparator NSAIDs. In the pooled analysis, nabumetone was associated with a significantly lower total incidence of ulcers and bleeding events, and a significantly lower incidence of complications associated with these events.

Diagnosis and treatment of nonsteroidal anti-inflammatory drug-associated upper gastrointestinal toxicity

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed in the United States to treat pain and reduce inflammation from chronic inflammatory disorders such as rheumatoid arthritis and osteoarthritis. Approximately 40% of older Americans take NSAIDs. Chronic NSAID use carries a risk of peptic ulcer and other gastrointestinal disturbances. This article reviews the diagnosis of medication-induced ulcers based on clinical presentation, laboratory tests, and endoscopic findings to assist the clinician in early diagnosis and appropriate therapy. Risk factors for NSAID-induced ulcers include old age, poor medical status, prior ulcer, alcoholism, smoking, high NSAID dosage, prolonged NSAID use, and concomitant use of other drugs that are gastric irritants, such as alendronate, a bone resorption inhibitor prescribed for osteoporosis. Appropriate treatment options for patients with medication-induced ulcers include dosage reduction, medication substitution, medication withdrawal, antiulcer therapy, and discontinuation of other gastrotoxic drugs.

Quantitative estimation of rare adverse events which follow a biological progression: a new model applied to chronic NSAID use

Randomised controlled trials (RCTs) alone are unlikely to provide reliable estimates of the incidence of rare events because of their limited size. Cohort, case control, and other observational studies have large numbers but are vulnerable to various kinds of bias. Wanting to estimate the risk of death from bleeding or perforated gastroduodenal ulcers with chronic usage of non-steroidal anti-inflammatory drugs (NSAIDs) with greater precision, we developed a model to quantify the frequency of rare adverse events which follow a biological progression. The model combined data from both RCTs and observational studies. We searched systematically for any report of chronic (>/=2 months) use of NSAIDs which gave information on gastroduodenal ulcer, bleed or perforation, death due to these complications, or progression from one level of harm to the next. Fifteen RCTs (19364 patients exposed to NSAIDs for 2-60 months), three cohort studies (215076 patients redeeming a NSAID prescription over a 3-12 month period), six case-control studies (2957 cases) and 20 case series (7406), and case reports (4447) were analysed. In RCTs the incidence of bleeding or perforation in 6822 patients exposed to NSAIDs was 0.69%; two deaths occurred. Of 11040 patients with bleeding or perforation with or without NSAID exposure across all reports, 6-16% (average 12%) died; the risk was lowest in RCTs and highest in case reports. Death from bleeding or perforation in all controls not exposed to NSAIDs occurred in 18 out of 849489 (0.002%). From these numbers we calculated the number-needed-to-treat for one patient to die due to gastroduodenal complications with chronic (>/=2 months) NSAIDs as 1/((0.69x¿6-16%, average 12%¿)-0.002%))=909-2500 (average 1220). On average 1 in 1200 patients taking NSAIDs for at least 2 months will die from gastroduodenal complications who would not have died had they not taken NSAIDs. This extrapolates to about 2000 deaths each year in the UK.

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.

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.

Tolerability and efficacy of nabumetone and naproxen in the treatment of rheumatoid arthritis

OBJECTIVE

The purpose of this study was to compare the tolerability and efficacy of nabumetone and naproxen in the treatment of patients with rheumatoid arthritis (RA). The occurrence of gastrointestinal (GI) adverse events was compared.

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) have similar efficacy at equipotent doses, but the therapeutic response to various NSAIDs often differs in individual patients.

METHODS

This was a 3-month, randomized, double-blind, multicenter, parallel-group study conducted in adult patients with RA. The study had 2 phases: a 3- to 14-day washout period and a 12-week treatment period. During the treatment phase, the tolerability and efficacy of nabumetone 2000 mg/d were compared with those of naproxen 1000 mg/d. The change from baseline in efficacy variables, including global assessments, number of tender or swollen joints, and pain, was evaluated. The study was sized to provide an 80% power to detect a 15% difference in the percentage improvement on the physician's global assessment (alpha = 0.05). GI safety was assessed by monitoring the occurrence of clinically important adverse GI events.

RESULTS

A total of 346 RA patients at 31 US rheumatology centers were randomly assigned to treatment (173 patients per group). The study population was predominantly white (87.0%) and female (70.5%), with a mean age of 54 years. Both treatments improved the signs and symptoms of RA, with no statistically significant differences between groups for any efficacy variables. No serious GI adverse events occurred with either NSAID. The most frequent treatment-related adverse events in both groups were predominantly GI in origin, as were those that resulted in withdrawal from the study. Diarrhea with lower abdominal pain was the most common adverse event in the nabumetone group; upper abdominal pain was the most common adverse event in the naproxen group. The only significant difference between the 2 groups was a higher incidence of diarrhea (P < 0.01) in patients receiving nabumetone.

CONCLUSIONS

Nabumetone 2000 mg/d was as effective as naproxen 1000 mg/d in relieving the signs and symptoms of RA. In this study, no serious GI adverse events were observed with either NSAID, but nabumetone was associated with a higher incidence of diarrhea.

Gastrointestinal safety profile of nabumetone: a meta-analysis

Individual comparative studies suggest that nabumetone has a gastrointestinal (GI) safety profile superior to comparator NSAIDs but lack power to show a statistical difference. The aim of this study was to evaluate systematically the difference in GI adverse events--especially the rate of perforations, ulcers, and bleeds (PUBs)-- between studies, meta-analyses of comparative trials of nabumetone and conventional NSAIDs, and postmarketing, open-label studies of nabumetone meeting predefined inclusion and exclusion criteria. A fully recursive literature search identified 13 studies consisting of 29 treatment arms and 49,501 patients that met the predefined criteria. Tests for heterogeneity found no significant difference between studies of each subgroup. Overall, the dyspeptic symptoms flatulence, constipation, and diarrhea were the most commonly reported adverse events accounting for 98.6% of the total GI adverse events. Significantly more patients treated with a comparator NSAID experienced GI adverse events than did those taking nabumetone (P = 0.007). After adjustment for patient-exposure years, PUBs were 10 to 36 times more likely to develop in patients treated with a comparator NSAID than with nabumetone. This was consistently seen in patients in nonendoscopic (n = 7,468) and endoscopic studies (n = 244). In the analysis of postmarketing or open-label studies of nabumetone, only one PUB was reported per 500 patient-exposure years over 17,502 treatment years (n = 39,389). GI adverse event-related dropouts and hospitalizations were increased by 1.3- and 3.7-fold if patients were treated with a comparator NSAID than with nabumetone. Significantly fewer treatment-related GI adverse events, especially PUBs, are seen in patients treated with nabumetone than with a comparator NSAID. Nabumetone is very safe for the GI tract.

Rationalizing cyclooxygenase (COX) inhibition for maximal efficacy and minimal adverse events

New information indicates that cyclooxygenase-2 (COX-2) is constitutively expressed in several tissues, including brain, lung, pancreas, kidney, and ovary, and plays an important role in renal and gastrointestinal function. Selective COX-2 inhibition has been associated in animal studies with impairment of ulcer healing and renal function and inhibition of prostacyclin, an effect that inhibits vasodilation without inhibiting platelet aggregation. The clinical consequences, if any, of these effects remain to be determined in long-term studies in humans. The premise that selective COX-2 inhibitors will cause less gastrointestinal toxicity than nonsteroidal antiinflammatory drugs that inhibit both COX isoforms needs to take into account the low toxicity of nabumetone. The gastrointestinal safety profile of this nonacidic, dual COX inhibitor that does not undergo enterohepatic circulation has been evaluated in extensive clinical trials. The data submitted to the US Food and Drug Administration in the New Drug Application for nabumetone (Relafen), the comparative trials subsequently completed, the published databases of the comparative gastrointestinal toxicity of various nonsteroidal anti-inflammatory drugs (NSAIDs), and the meta-analysis published in this issue of The American Journal of Medicine (Schoenfeld, page 48S) indicate that nabumetone has the lowest incidence of gastrointestinal toxicity among the extensively studied NSAIDs. Overall, the incidence is approximately 10-fold less than with comparator drugs. This rate is an appropriate current reference against which the gastrointestinal toxicity of COX-2 inhibitors can be compared.

Profile and mechanisms of gastrointestinal and other side effects of nonsteroidal anti-inflammatory drugs (NSAIDs)

The popular view that all nonsteroidal anti-inflammatory drugs (NSAIDs) act by inhibiting the production of prostaglandins has been challenged by the discovery that they also affect a wide variety of cellular processes that are important for their therapeutic actions and side effects. Although recognition of the differential activities of new and established NSAIDs on the activities of the cyclooxygenases (COXs) affecting production of inflammatory prostaglandins (from COX-2) and those that are physiologically important (from COX-1) may have significance for the prostaglandin components of the underlying inflammatory and physiologic processes, there are important features of their chemical structures that determine the various cellular and biochemical actions of these agents. Several established NSAIDs have low propensity to cause gastrointestinal (GI) ulceration and bleeding that may relate to these drugs having unique pharmacokinetic characteristics (pro-drugs, protein binding, etc). They also have weak effects on the production of GI mucosal prostaglandins and have specific physicochemical characteristics such that they cause minimal damage to mucosal membranes or effects on nonprostaglandin-related cellular mechanisms important in mucosal defenses. Some of the new COX-2-selective drugs with methyl or amino-sulfonyl moieties have relatively high pKa values and other properties that are similar to established NSAIDs with low GI ulcerogenicity. These physicochemical properties may contribute to the low irritancy of the new COX-2-selective drugs quite apart from their sparing of COX-1 in the GI mucosa. With concerns that some established NSAIDs may accelerate cartilage destruction in osteoarthritis (OA), interest is now focusing on whether the COX-2-selective drugs may have a lower potential for this adverse effect by avoiding the inhibitory effects on cartilage proteoglycan metabolism seen with such drugs as indomethacin and the salicylates. Meloxicam appears to be without inhibitory effects on proteoglycan metabolism, but it remains to be seen if this translates into any beneficial actions on the progression of joint changes in OA observed radiologically or from magnetic resonance imaging.

Comparative toxicity of nonsteroidal anti-inflammatory drugs

To compare the gastrointestinal (GI) toxicities of various nonsteroidal anti-inflammatory drugs (NSAIDs), it is first necessary to dismantle the imprecise entity "NSAID gastropathy" into its component conditions, and understand their pathogenesis. In this article, toxicities are reviewed only in so far as they affect the upper GI tract, the site of approximately 80% of GI injuries caused by NSAIDs. The phenomena discussed are platelet dysfunction, causing hemorrhage from various lesions, including but not confined to ulcers; various mucosal injuries, ranging from small erosions to large ulcers; and "complications," such as bleeding or perforations, causing admission to hospital, that may arise from ulcers but may also arise from other lesions. Ulcers, when complicated, may either be those caused by an NSAID or "peptic" ulcers that preceded NSAID therapy (having a high prevalence in the population) and gave rise to complications resulting from NSAID effects on platelets, tissues, or biologic processes, for example, healing, necrosis/apoptosis, leukocyte adherence, vasoconstriction, or generation of free radicals. NSAIDs have been compared in various ways, including fecal blood loss, endoscopic lesion development, prospective preclinical cohort studies measuring perforations, ulcers, and bleeds, post-marketing surveillance studies, and studies of the incidence of serious adverse events in populations followed in large databases linked to each individual patient record with regard to drug consumption and outcome. All methods show considerable differences between NSAIDs. Modern studies on the relative toxicities of NSAIDs are summarized and reviewed, and a number of marketed and emerging drugs that appear less toxic than classic NSAIDs are identified.

The effect of hip replacement on prescribing of NSAIDs, ulcer healing drugs and hospitalization—a matched cohort study

PURPOSE

To assess the impact of total hip replacement on prescribing of non-steroidal anti-inflammatory drugs (NSAIDs), ulcer healing drugs (UHDs) and hospitalization.

METHODS

Observational matched cohort study.

RESULTS

There were 282 subjects in the hip replacement cohort and 1691 in the comparator cohort. Dispensing of NSAIDs fell from 89% to 57% after hip replacement but increased from 36% to 39% in comparators. Dispensing of UHDs fell from 33% to 30% after hip replacement but increased from 16% to 23% in the comparators. Hospitalization for upper gastrointestinal events fell from 2.5% to 1.8% after hip replacement but increased from 1.4% to 1.7% in comparators. Hospitalization for other causes increased from 32% to 42% after hip replacement compared with 25% to 28% in comparators.

CONCLUSIONS

Hip replacement is associated with reduced prescribing of NSAIDs and UHDs. However, any effect on GI admissions will be small compared with increased hospitalization for other causes.

An endoscopic study of gastroduodenal lesions induced by nonsteroidal anti-inflammatory drugs

Rheumatoid arthritis (RA) and osteoarthritis (OA) are frequently treated with nonsteroidal anti-inflammatory drugs (NSAIDs). Although NSAIDs are an effective therapy for the pain and inflammation of arthritis, they are associated with serious side effects, particularly ulceration, bleeding, and perforation of the gastrointestinal (GI) tract. In this study, 1826 OA or RA patients who either had been taking NSAIDS for > or =6 months or had been unable to tolerate continuous NSAID use because of adverse GI symptoms or suspected NSAID-related gastroduodenal lesions were examined endoscopically for gastroduodenal lesions and ulcers. At the same time, the patients were asked to rate the severity of any GI symptoms they had been experiencing. Of the total number of patients studied, 817 (44.7%) were OA patients with a mean (+/- SD) age of 55.8+/-12.9 years, and 1009 (55.3%) were RA patients with a mean age of 53.1+/-13.1 years. Clinically significant gastroduodenal lesions were found in 37.1% of patients (n = 678); of these, 24.0% (n = 439) had ulcers. Gastric ulcers were more frequent than duodenal ulcers (14.8% vs 10.2% of patients; P < 0.05), and most gastric ulcers (72.0%) were found in the antrum of the stomach. The prevalence of gastroduodenal ulcers increased with age (P < 0.001), duration of OA (P < 0.001), and duration of current NSAID use (P = 0.019). The prevalence of gastroduodenal ulcers in patients taking NSAIDs for <1 year was 13.8%, compared with a nearly twofold higher prevalence (25.9%) in patients taking NSAIDs for periods of > or =1 year and up to 15 years. The prevalence of gastric ulcers was 32.6% in patients with a history of gastric ulcer but only 13.5% in patients with no GI history (previous gastric ulcer, duodenal ulcer, or upper GI hemorrhage). No relationship was found between the prevalence of gastroduodenal ulcers and sex (men, 22.4%; women, 24.9%) or prevalence of gastroduodenal ulcers and type of arthritic disease (RA, 23.6%; OA, 24.5%). The prevalence of gastroduodenal ulcers increased with the severity of GI symptoms (P = 0.007). These results provide further endoscopic confirmation of the association between NSAID use and gastroduodenal lesions and ulcers and support the contention that safer treatment alternatives to conventional NSAIDs are required.

4,5-Diaryloxazole inhibitors of cyclooxygenase-2 (COX-2)

A series of methysulfonyl or sulfonamido substituted 4,5-diaryloxazole were prepared and evaluated for their ability to inhibit the inducible form of cyclooxygenase (COX-2) in vitro and in vivo. Several unique substitution patterns were identified that led to potent and selective inhibitors of COX-2. In general, 2-trifluoromethly-4,5-diaryloxazoles substituted with a methylsulfonyl or sulfonamido group were particularly potent inhibitors. One of the more potent compounds with a selectivity for COX-2 of about 800 fold was 4b (SC-299). SC-299, a highly fluorescent molecule, may be useful for spectroscopic studies on preferential inhibitor binding to COX-2.

Bovine colostrum is a health food supplement which prevents NSAID induced gut damage

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are effective for arthritis but cause gastrointestinal injury. Bovine colostrum is a rich source of growth factors and is marketed as a health food supplement.

AIMS

To examine whether spray dried, defatted colostrum or milk preparations could reduce gastrointestinal injury caused by indomethacin.

METHODS

Effects of test solutions, administered orally, were examined using an indomethacin restraint rat model of gastric damage and an indomethacin mouse model of small intestinal injury. Effects on migration of the human colonic carcinoma cell line HT-29 and rat small intestinal cell line RIE-1 were assessed using a wounded monolayer assay system (used as an in vitro model of wound repair) and effects on proliferation determined using [3H]thymidine incorporation.

RESULTS

Pretreatment with 0.5 or 1 ml colostral preparation reduced gastric injury by 30% and 60% respectively in rats. A milk preparation was much less efficacious. Recombinant transforming growth factor beta added at a dose similar to that found in the colostrum preparation (12.5 ng/rat), reduced injury by about 60%. Addition of colostrum to drinking water (10% vol/vol) prevented villus shortening in the mouse model of small intestinal injury. Addition of milk preparation was ineffective. Colostrum increased proliferation and cell migration of RIE-1 and HT-29 cells. These effects were mainly due to constituents of the colostrum with molecular weights greater than 30 kDa.

CONCLUSIONS

Bovine colostrum could provide a novel, inexpensive approach for the prevention and treatment of the injurious effects of NSAIDs on the gut and may also be of value for the treatment of other ulcerative conditions of the bowel.

The use of analgesics in the management of pain in rheumatic diseases

Pain is the most common complaint of patients who see rheumatologists. In this article, the current treatment options for pain are reviewed; these include acetaminophen, nonsteroidal anti-inflammatory drugs, new specific cyclooxygenase-2 inhibitors, opioid analgesics, centrally acting muscle relaxants, antidepressants, and topical analgesics and counterirritants. The doses of medication and known adverse effects of these medications are highlighted.