A double-blind gastroscopic evaluation of the effects of etodolac and naproxen on the gastrointestinal mucosa of rheumatic patients

Meta-analysis of dyspepsia and nonsteroidal antiinflammatory drugs

OBJECTIVE

Nonsteroidal antiinflammatory drug (NSAID) use is a known risk factor for gastrointestinal (GI) perforations, ulcers, and bleeds, but there are limited data on its association with the very common symptom of dyspepsia. Using published and unpublished data sources, we sought to determine estimates of the risks of dyspepsia associated with NSAIDs.

METHODS

We searched computerized databases (1966-1998) for primary studies of NSAIDs reporting on GI complications. We also obtained Food and Drug Administration (FDA) new drug application reviews for the 5 most common NSAIDs. We included studies reporting defined upper GI outcomes among subjects (>17 years old) who used oral NSAIDs for more than 4 days. Two reviewers evaluated 4,881 published titles, identifying 55 NSAID versus placebo randomized controlled trials (RCTs), 37 unpublished (FDA data) placebo-controlled RCTs; 86 NSAID versus NSAID RCTs (sample size >or=50); and 103 observational studies.

RESULTS

The majority of clinical trials were of good quality. Meta-regression identified an increased risk of dyspepsia for users of specific NSAIDs (adjusted odds ratio [OR] of indomethacin, meclofenamate, piroxicam = 2.8), and for high dosages of other NSAIDs (OR = 3.1), but not for other NSAIDs regardless of dosage (OR = 1.1). Dyspepsia was not reported as an outcome in the case control or cohort studies.

CONCLUSIONS

Clinical trial data indicate that high dosages of any NSAID along with any dosage of indomethacin, meclofenamate, or piroxicam increase the risk of dyspepsia by about 3-fold. Other NSAIDs at lower dosages were not associated with an increased risk of dyspepsia.

COX-2 inhibitors compared and contrasted

Non-steroidal anti-inflammatory drugs (NSAIDs) are the principal drug treatments for inflammation, pain and fever. They act primarily by inhibiting prostaglandin (PG) synthesis but this can cause adverse events (AEs). Since the discovery of two PG synthesising enzymes, COX-1 and COX-2, and the substantial evidence that sparing COX-1 is advantageous for gastric safety, great interest has focused on selective COX-2 inhibitors. Much of the impetus has come from the most recently developed compounds celecoxib and rofecoxib, which have shown spectacular sales growth. However, the older drugs etodolac, nimesulide and meloxicam, made before COX-2 was discovered, are also COX-1-sparing and have good GI safety and therapeutic activities. These five compounds show similarities and differences that are discussed in relation to aspects that include their uses, efficacy, actions and safety.

A randomized trial comparing the effect of rofecoxib, a cyclooxygenase 2-specific inhibitor, with that of ibuprofen on the gastroduodenal mucosa of patients with osteoarthritis. Rofecoxib Osteoarthritis Endoscopy Study Group

BACKGROUND & AIMS

Prostaglandin production in the normal gastrointestinal tract, believed to be critical for mucosal integrity, is mediated by cyclooxygenase (COX)-1, whereas prostaglandin production at inflammatory sites seems to occur via induction of COX-2. We hypothesized that COX-2-specific inhibition with rofecoxib (25 mg once daily) in the treatment of patients with osteoarthritis would cause fewer gastroduodenal ulcers than an equally effective dose of ibuprofen (800 mg 3 times a day), a nonspecific COX inhibitor.

METHODS

A total of 742 osteoarthritis patients without ulcers on baseline endoscopy were randomly assigned to receive rofecoxib (25 or 50 mg once daily), ibuprofen (800 mg 3 times daily), or placebo. Endoscopy was repeated at 6, 12, and 24 weeks. At 16 weeks, by study design, 95% of the placebo group and 5% of the other groups were discontinued.

RESULTS

The cumulative incidence of gastroduodenal ulcers >/=3 mm with rofecoxib (25 or 50 mg once daily) was significantly (P < 0.001) lower than with ibuprofen and was statistically equivalent to placebo at week 12 (placebo, 9.9%; 25 mg rofecoxib, 4.1%; 50 mg rofecoxib, 7.3%; and ibuprofen, 27.7%). At 24 weeks, ulcer rates were 25 mg rofecoxib, 9. 6%; 50 mg rofecoxib, 14.7%; and ibuprofen, 45.8% (P < 0.001, ibuprofen vs. 25 and 50 mg rofecoxib).

CONCLUSIONS

Rofecoxib, at doses 2-4 times the dose demonstrated to relieve symptoms of osteoarthritis, caused significantly less gastroduodenal ulceration than ibuprofen, with ulcer rates comparable to placebo.

Safety profiles of leading nonsteroidal anti-inflammatory drugs

Recently introduced nonsteroidal anti-inflammatory drugs (NSAIDs) have capitalized on new formulations or unique physical and pharmacologic properties in an attempt to provide a greater margin of gastrointestinal (GI) safety. The use of enteric coatings and nonoral or pro-drug formulations have not necessarily provided the expected safety, but other properties have been identified that appear to be more promising. However, as demonstrated by oxaprozin, considered to be one of the least safe NSAIDs but one of the leading drugs on the US market, success may not be dependent on safety. In contrast, the improved tolerability of 2 other new NSAIDs, nabumetone and etodolac, has been established in clinical trials and limited postmarketing surveillance. This improved tolerability is probably associated with several pharmacologic properties that have been suggested to contribute to GI safety: (1) nonacidic pro-drug formulation; (2) lack of enterohepatic recirculation; (3) a short plasma half-life; and (4) preferential inhibition of cyclo-oxygenase-2 (COX-2). Although these factors may not improve efficacy, their incorporation into the design of drugs suggests that safer NSAIDs may be a clinical reality. However, the safety and clinical value of any new drug for the general population will be validated only through extensive postmarketing surveillance.

Future trends in the development of safer nonsteroidal anti-inflammatory drugs

Gastrointestinal (GI) adverse events, ranging from mild to life-threatening, are well-recognized sequelae to nonsteroidal anti-inflammatory drug (NSAID) use. Recent improvements in our knowledge of the mechanisms responsible for NSAID-associated gastropathy have enabled several experimental approaches to decreasing the risk of these events. Whereas such strategies as preassociation of NSAIDs to zwitterionic phospholipids to prevent NSAID-mucosal interactions and concomitant administration of trefoil peptides to stimulate mucosal defense pathways represent novel approaches, their clinical feasibility remains to be determined. Other strategies that appear more immediately promising in the reduction of NSAID-associated GI toxicity are the coupling of NSAIDs to nitric oxide (NO)-releasing compounds and the introduction of NSAIDs that are preferential or specific for cyclo-oxygenase-2 (COX-2), the isoform implicated in the inflammatory response. Clinical trials of several specific COX-2 inhibitors, as well as European clinical data for a preferential COX-2 inhibitor, meloxicam, suggest that COX-2 inhibitors provide an advantage over standard NSAIDs in terms of GI tolerability. However, as recent observations have implicated COX-2 as an integral component in the maintenance of physiologic homeostasis, careful scrutiny of both the beneficial and the deleterious effects of the selective COX-2 inhibitors is requisite before their approval and widespread use. Furthermore, based on the physiologic importance of COX-2, the preferential inhibitors may ultimately prove to represent the optimal compromise for the treatment of various arthritides.

A randomized double-blind comparison of placebo, etodolac, and naproxen on gastrointestinal injury and prostaglandin production

BACKGROUND

NSAIDs frequently cause gastrointestinal injury and increase the risk of ulcer complications. We compared an NSAID suggested to cause less gastric injury (etodolac) with a standard NSAID (naproxen) and a placebo in a 4-week double-blind trial assessing the effects on gastroduodenal injury, symptoms, and prostaglandin production in healthy volunteers.

METHODS

Fifty-two healthy volunteers not taking NSAIDs, alcohol, antibiotics, bismuth, or anti-ulcer drugs: placebo, etodolac 400 mg, or naproxen 500 mg b.i.d. for 4 weeks. Endoscopies with biopsies were repeated at weeks 1 and 4. The number and dimensions of ulcers and erosions were recorded to quantitate injury.

RESULTS

At week 1 the mean number and area of gastric ulcers per subject were greater with naproxen than placebo or etodolac (area: naproxen, 7.4 mm2; placebo, 0.6 mm2, p = 0.02 vs naproxen; etodolac, 2.1 mm2, p = 0.06 vs naproxen). Ulcer scores at week 4 were low and comparable in the three groups. The mean number and area of gastric erosions per subject were greatest with naproxen at both weeks 1 and 4 (week 4 area: naproxen, 58.3 mm2; placebo, 29.0 mm2; etodolac, 13.9 mm2, p < 0.02, naproxen vs placebo and vs etodolac). Placebo injury was presumably due to biopsies at prior endoscopy. Gastric mucosal prostaglandin E2 production did not change significantly from baseline after 1 or 4 weeks of treatment with placebo or etodolac, but did decrease significantly with naproxen (week 0, 1689; week 1, 479; week 4, 577 pg/mg protein). Gastrointestinal symptoms were present in only 1 (5%) of 20 visits in which endoscopy showed no erosions or ulcers vs 21 (26%) of 82 visits in which a mucosal defect was identified (p = 0.666).

CONCLUSION

Gastric injury with 4 weeks of etodolac is comparable to that seen with placebo and significantly less than that occurring with naproxen, presumably due to the fact that etodolac does not suppress gastric mucosal prostaglandin production, whereas naproxen leads to a significant reduction.

Interaction of NSAIDs and Helicobacter pylori on gastrointestinal injury and prostaglandin production: a controlled double-blind trial

BACKGROUND

H. pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) are major causes of gastroduodenal injury in man. We assessed the effect of daily NSAID ingestion on gastric histology and the interaction of H. pylori infection and NSAID ingestion on gross and histological injury and prostaglandin production.

METHODS

Fifty-two healthy volunteers with normal baseline endoscopy were randomly assigned to receive identical-appearing naproxen 500 mg b.d., etodolac 400 mg b.d., or placebo b.d. for 4 weeks. The number and size of all erosions and ulcers were recorded by endoscopy at weeks 1 and 4. Biopsies taken at baseline, week 1 and week 4 were assessed for H. pylori, histology and gastric prostaglandin E2 production.

RESULTS

No significant changes occurred with treatment in any histological feature in the three study groups or in H. pylori positive or negative subsets. Antral inflammation scores (scale, 0-6) for the NSAID group were: week 0--1.2 +/- 0.3; week 1--1.1 +/- 0.3; week 4--1.3 +/- 0.3; findings of 'chemical gastritis' were not seen. No significant difference in gross gastroduodenal injury (number or total surface area of ulcers or erosions) was seen between H. pylori positive and negative subjects in the three groups at week 1 or 4. Baseline prostaglandin E2 production was significantly higher in H. pylori positive subjects (2398 +/- 400 vs. 1064 +/- 255 pg/mg protein) and decreased significantly with 1 week of naproxen in H. pylori positive and negative subjects.

CONCLUSIONS

NSAID ingestion does not cause diffuse histological injury. Any diffuse histological injury in the gastric mucosa is related to the presence of H. pylori, and this H. pylori-associated gastritis is not altered by NSAID ingestion. Furthermore, the development of gross gastroduodenal damage with 4 weeks of NSAID use is not influenced by underlying H. pylori infection.

A comparison of severe gastric damage as a result of pirprofen and naproxen treatment in rheumatoid arthritis: a controlled endoscopic study

OBJECTIVE

The aim of this controlled endoscopic study was to compare the therapeutic efficacy and the gastric tolerance of two nonsteroidal anti-inflammatory drugs, pirprofen versus naproxen.

DESIGN

A randomized endoscopic double-blind double-dummy study.

SETTING

The gastrointestinal unit of a teaching hospital.

SUBJECTS

Forty patients suffering from rheumatoid arthritis were enrolled. After an initial upper gastrointestinal endoscopy to rule out the presence of gastric mucosal lesions, the patients were randomly allocated in a double-blind, double-dummy manner, to receive either pirprofen (400 mg t.i.d.) or naproxen (500 mg b.i.d.) for 4 weeks; endoscopic control followed this treatment period, or was anticipated in the event of painful dyspepsia.

INTERVENTIONS

Endoscopy at the beginning of the study and at 4 weeks, or anticipated in the event of painful dyspepsia.

MAIN OUTCOME MEASURES

Primary outcome measure of the study was the possibility that pirprofen was less toxic to the gastric mucosa than naproxen, and at least as effective.

RESULTS

Both drugs proved effective in relieving clinical symptoms, without a statistically significant difference. Gastric mucosa lesions were observed in 90% of pirprofen-treated patients and in 60% of those on naproxen (P = 0.03). The most severe lesions (grades 3 and 4) were found in 65% of subjects treated with pirprofen, as opposed to 15% of those treated with naproxen (P = 0.001).

CONCLUSIONS

This study shows that pirprofen is at least as active as naproxen in relieving rheumatic symptoms, but its administration results in a significantly severe degree of gastric damage.

The safety profile of sustained-release etodolac

The safety profile of a new sustained-release (SR) form of etodolac was evaluated in 539 young and elderly patients with osteoarthritis or rheumatoid arthritis. Four long-term, open-label studies were conducted in nine different countries totaling 3,827 patient-months' exposure to etodolac SR. Patients were treated with either 400 mg or 600 mg etodolac SR once a day for up to 52 weeks. Withdrawals due to adverse reactions were low, occurring in only 5% (26/539) of all patients. The most common drug-related study events were GI-related, occurring in < 8% of patients. Elderly persons (> or = 65 years of age) were not at greater risk for adverse reactions or drug-related study events than were younger patients. Serious GI-related study events were rare (0.2%). The low level of serious GI effects was consistent with a separate study measuring gastrointestinal (GI) blood loss. Etodolac SR produced significantly less GI blood loss than naproxen in normal subjects. Because of its favorable safety profile, etodolac SR can serve as an alternative to conventional etodolac, providing the convenience of once-daily administration.

Etodolac. A reappraisal of its pharmacology and therapeutic use in rheumatic diseases and pain states

Etodolac is a nonsteroidal anti-inflammatory drug (NSAID) effective in the treatment of rheumatoid arthritis, osteoarthritis and ankylosing spondylitis, and in the alleviation of postoperative pain. Etodolac also provides relief of other types of pain, including that arising from gouty conditions and traumatic injury. In all indications, etodolac appears to be at least as effective as other NSAIDs. The incidence of clinical adverse effects other than abdominal pain and dyspepsia is similar to that observed with placebo, and etodolac has been associated with a low rate of gastrointestinal ulceration and other serious events. Data from preliminary animal studies have suggested that etodolac may provide more selective inhibition of prostaglandin synthesis at sites of inflammation than some other currently available NSAIDs. Thus, available evidence indicates that etodolac, with its low incidence of gastrointestinal events, is an effective and well tolerated alternative to other NSAIDs in the treatment of arthritic diseases and pain of various aetiologies and should be considered a first-line therapy.