An endoscopic evaluation of the effects of non-steroidal anti-inflammatory drugs on the gastric mucosa

Toward Understanding Drug Incorporation and Delivery from Biocompatible Metal-Organic Frameworks in View of Cutaneous Administration

Although metal-organic frameworks (MOFs) have widely demonstrated their convenient performances as drug-delivery systems, there is still work to do to fully understand the drug incorporation/delivery processes from these materials. In this work, a combined experimental and computational investigation of the main structural and physicochemical parameters driving drug adsorption/desorption kinetics was carried out. Two model drugs (aspirin and ibuprofen) and three water-stable, biocompatible MOFs (MIL-100(Fe), UiO-66(Zr), and MIL-127(Fe)) have been selected to obtain a variety of drug-matrix couples with different structural and physicochemical characteristics. This study evidenced that the drug-loading and drug-delivery processes are mainly governed by structural parameters (accessibility of the framework and drug volume) as well as the MOF/drug hydrophobic/hydrophilic balance. As a result, the delivery of the drug under simulated cutaneous conditions (aqueous media at 37 °C) demonstrated that these systems fulfill the requirements to be used as topical drug-delivery systems, such as released payload between 1 and 7 days. These results highlight the importance of the rational selection of MOFs, evidencing the effect of geometrical and chemical parameters of both the MOF and the drug on the drug adsorption and release.

Meta-analysis: incidence of endoscopic gastric and duodenal ulcers in placebo arms of randomized placebo-controlled NSAID trials

BACKGROUND

The safety of NSAIDs is often evaluated by comparison with placebo in clinical trials.

AIM

To investigate the incidence of gastric and duodenal ulcers (GDU) in placebo arms in NSAID trials over the last three decades.

METHODS

Randomized placebo-controlled trials of oral NSAIDs from 1975 to 2006 were systematically reviewed. The pooled incidence of GDU in placebo arms was calculated and compared. Meta-regression was used to identify risk factors related to the incidence of the placebo ulcer at the study level.

RESULTS

Thirty-six studies met inclusion criteria (duration of 6.5 days to 24 weeks). In total, 3.29% GDUs were reported in 36 placebo arms. The incidence of GDU in placebo arms was 0, 4.20% and 3.03% in the studies from 1975-1989, 1990-1999 and 2000-2006 respectively (P > 0.05). Eligible subjects with previous GI events and eligible subjects on co-therapy with low-lose aspirin/corticosteroids were associated with the increase in placebo ulcer incidence after adjusting for other factors.

CONCLUSIONS

The incidence of GDU in placebo arms has not changed significantly over the last three decades, although has decreased in the past 10 years. Studies show that previous GI events and co-therapy with low-dose aspirin/corticosteroids were associated with increasing GDU in placebo arms.

Gastrointestinal tolerability of lumiracoxib in patients with osteoarthritis and rheumatoid arthritis

BACKGROUND & AIMS

The aim of this study was to evaluate the gastrointestinal safety of lumiracoxib, a novel selective cyclooxygenase-2 inhibitor.

METHODS

Results from 15 Phase II and III randomized studies of lumiracoxib in osteoarthritis and rheumatoid arthritis were pooled. Patients received lumiracoxib (200/400 mg/day), celecoxib (200/400 mg/day), rofecoxib (25 mg once daily), diclofenac (75 mg twice daily), ibuprofen (800 mg 3 times daily), naproxen (500 mg twice daily), or placebo. Outcome measures included the incidence of definite or probable ulcer complications (perforations, obstructions, or bleedings as confirmed by an adjudication committee) and symptomatic upper gastrointestinal ulcers, the incidence of prespecified gastrointestinal adverse events, and the discontinuation rate caused by adverse events. All suspected ulcer complications in these 15 studies were adjudicated prospectively. Data from 2 endoscopic studies were pooled separately to assess the cumulative incidence of gastroduodenal ulcers >or=3 mm in diameter.

RESULTS

Symptomatic upper gastrointestinal ulcers and ulcer complications were reduced nearly 10-fold with lumiracoxib (1.7 events per 100 patient-years [95% confidence interval, 1.09-2.39]) compared with nonselective nonsteroidal anti-inflammatory drugs (13.7 events per 100 patient-years [95% confidence interval, 9.47-18.82]). Symptomatic ulcer frequency was markedly lower with lumiracoxib (0.4%) than with nonselective nonsteroidal anti-inflammatory drugs (2.5%). Discontinuation rates due to gastrointestinal adverse events were higher for nonselective nonsteroidal anti-inflammatory drugs (8.4%) than for lumiracoxib (3.3%). In the endoscopy analysis, the cumulative frequency of ulcers >or=3 mm in diameter was reduced by >70% for lumiracoxib versus ibuprofen.

CONCLUSIONS

Lumiracoxib exhibited a gastrointestinal safety profile superior to nonselective nonsteroidal anti-inflammatory drugs.

Reduced incidence of gastroduodenal ulcers associated with lumiracoxib compared with ibuprofen in patients with rheumatoid arthritis

BACKGROUND

Lumiracoxib (Prexige; Novartis Pharma AG, Basel, Switzerland) is a cyclooxygenase-2 selective inhibitor associated with improved gastrointestinal safety compared with nonsteroidal anti-inflammatory drugs, in patients with osteoarthritis.

AIM

To compare the gastroduodenal safety of lumiracoxib with ibuprofen and celecoxib in patients with rheumatoid arthritis.

METHODS

A total of 893 patients with rheumatoid arthritis were randomized to lumiracoxib 400 mg once daily, lumiracoxib 800 mg once daily, ibuprofen 800 mg three times daily or celecoxib 200 mg twice daily for 13 weeks, in a double-blind randomised controlled clinical trial. The primary endpoint was the cumulative incidence of gastroduodenal ulcers over 13 weeks.

RESULTS

The incidence of gastroduodenal ulcers >/=3 mm with lumiracoxib 400 mg once daily (2.8%) or lumiracoxib 800 mg once daily (4.3%) was significantly lower than with ibuprofen (13.6%, all P < 0.01) and not different from celecoxib (1.9%). The incidence of adverse events was similar for lumiracoxib 400, 800 mg and celecoxib (78, 75 and 77%, respectively) and higher with ibuprofen (86%). Discontinuation for adverse events was highest for ibuprofen (12.5% vs. 7.9-8.8% for the other groups).

CONCLUSIONS

Lumiracoxib demonstrated gastroduodenal safety superior to ibuprofen and similar to celecoxib in patients with rheumatoid arthritis.

A randomized, controlled comparison of ibuprofen at the maximal over-the-counter dose compared with prescription-dose celecoxib on upper gastrointestinal mucosal injury

BACKGROUND & AIMS

Ibuprofen is a well-tolerated nonsteroidal anti-inflammatory drug (NSAID), particularly at over-the-counter (OTC) doses. Cyclooxygenase 2 (COX-2)-selective inhibitors cause less ulceration than prescription-dose nonselective NSAIDs. We compared endoscopic injury related to nonprescription ibuprofen doses with celecoxib, also comparing prescription doses of naproxen with placebo as a positive control.

METHODS

The study was a randomized, placebo-controlled, double blind, double-dummy endoscopic evaluation with concealed allocation. A 2-way crossover with a 4-5-week washout period was used. Participants were healthy adults with normal baseline findings from endoscopy. Ninety-five subjects were randomly assigned, and 79 subjects completed both study phases. Age distribution was reflective of the target population of the OTC agent. Twenty percent were infected with Helicobacter pylori, and 79% and 67% had a current or past medical problem, respectively. Qualifying subjects, stratified by the presence or absence of H. pylori infection (n = 20), were randomly assigned to 1 of the 4 sequences (phase I/II) as follows: ibuprofen/celecoxib; celecoxib/ibuprofen, naproxen/placebo, or placebo/naproxen. Primary end points were the frequency of endoscopic ulcers and erosions in the groups administered: (1) celecoxib vs. ibuprofen and (2) naproxen vs. placebo.

RESULTS

In celecoxib-treated subjects, 2.6% developed ulcers compared with 17.9% of those treated with ibuprofen (P = 0.056). Naproxen treatment was associated with a significantly greater ulceration rate compared with placebo.

CONCLUSIONS

Short-term use of the nonselective COX inhibitors ibuprofen and naproxen is associated with a greater risk for endoscopic mucosal injury compared with the COX-2-selective inhibitor celecoxib or placebo. A prospective analysis appropriately powered to address the incidence of clinically significant gastroduodenal ulceration associated with the short-term use of these agents would be required to further define the clinical relevance of these findings.

Gastroduodenal tolerability of lumiracoxib vs placebo and naproxen: a pilot endoscopic study in healthy male subjects

BACKGROUND

Lumiracoxib (Prexige) is a cyclooxygenase-2 (COX-2) selective inhibitor.

AIM

To compare the gastroduodenal tolerability of lumiracoxib with placebo and naproxen in a randomized, parallel-group, double-blind study.

METHODS

: Sixty-five healthy male subjects were randomized to receive 8 days' dosing with lumiracoxib 200 mg twice daily (b.d.) (n = 21), placebo (n = 22) or naproxen 500 mg b.d. (n = 22). Endoscopic evaluations of gastric and duodenal mucosae were conducted at baseline and after 8 days' dosing. Serum was assayed for ex-vivo concentrations of thromboxane B2 (TxB2) to determine cyclooxygenase-1 (COX-1) inhibitory activity.

RESULTS

Sixty subjects (20 per group) completed the study. No gastroduodenal erosions were observed in subjects receiving lumiracoxib. Thirteen subjects receiving naproxen developed duodenal erosions. At the gastric site, one subject in each of the naproxen and placebo groups had erosions; one subject receiving naproxen also developed a small asymptomatic gastric ulcer. Gastrointestinal adverse events accounted for 42.3% of all adverse events, occurring in 3/21, 4/22 and 6/22 of the lumiracoxib, placebo and naproxen groups, respectively. TxB2 levels were similar for patients receiving placebo or lumiracoxib, but were reduced by > 95% in patients receiving naproxen, compared with placebo.

CONCLUSIONS

Multiple doses of lumiracoxib resulted in gastroduodenal tolerability similar to placebo and superior to naproxen.

Radiographically diagnosed antral gastritis: findings in patients with and without Helicobacter pylori infection

The purpose of this study was to characterize the radiographic findings of antral gastritis and to determine whether there are differences in the appearance of antral gastritis in patients with and without Helicobacter pylori infection. A search of radiology, endoscopy and pathology files revealed 90 patients with antral gastritis on double contrast upper gastrointestinal tract studies who had endoscopy with testing for H. pylori. The barium studies were evaluated to further characterize the findings of antral gastritis without knowledge of the H. pylori status of the patients or of the endoscopy or pathology findings. The radiographic findings of antral gastritis included thickened folds in 67 patients (74%), polypoid antral gastritis (a subset of patients with thickened folds) in 6 (9%), antral erosions in 21 (23%), enlarged areae gastricae in 14 (16%), crenulation of the lesser curvature in 4 (4%), mucosal nodularity in 2 (2%), a hypertrophied antral-pyloric fold in 2 (2%) and antral striae in 1 (1%). 43 patients (48%) with antral gastritis were H. pylori positive and 47 patients (52%) were H. pylori negative. Thickened folds were detected in 39 H. pylori-positive patients (91%) with antral gastritis vs 28 H. pylori-negative patients (60%) (p<0.001); polypoid gastritis in 6 H. pylori-positive patients (14%) vs 0 H. pylori-negative patients (p<0.05); enlarged areae gastricae in 14 H. pylori-positive patients (33%) vs 0 H. pylori-negative patients (p<0.0001); and antral erosions in 2 H. pylori-positive patients (5%) vs 19 H. pylori-negative patients (40%) (p<0.0001). Our experience suggests that antral gastritis caused by H. pylori infection is associated with characteristic features on double contrast studies (including thickened folds, polypoid gastritis and enlarged areae gastricae) and that this condition is rarely associated with antral erosions. Thus, radiologists can often suggest whether the patient's gastritis is caused by H. pylori on the basis of radiographic findings.

Low levels of gastric mucosal glutathione during upper gastric bleeding associated with the use of nonsteroidal anti-inflammatory drugs

OBJECTIVES

To investigate the glutathione concentrations in gastric mucosa from patients with acute gastric bleeding related to nonsteroidal anti-inflammatory drugs (NSAIDs), and to test the influence of nutritional status on mucosal glutathione. Glutathione protects the gastrointestinal mucosa against reactive oxygen species, and glutathione content in various tissues may be depleted during malnutrition.

METHODS

Endoscopic biopsies were obtained from 39 patients. Eighteen of these (9 well-nourished, 9 malnourished) presented with gastric bleeding ulcers related to NSAIDs. Twenty-one other patients (12 well-nourished, 9 malnourished) underwent normal routine diagnostic endoscopy and served as controls. Malnutrition was defined as a loss of over 10% of normal body weight and/or plasma albumin levels below 30 g/l. Gastric biopsies were taken from the fundus and antrum (controls) and from the region of the ulcer (patients with acute bleeding) and frozen quickly until glutathione analysis by high-performance liquid chromatography (HPLC) coulometric detection. Results were expressed as nmol/mg wet tissue.

RESULTS

Gastric mucosal glutathione levels were significantly (P < 0.05) lower in both the antrum (0.81 +/- 0.34 v. 1.41 +/- 0.88 nmol/mg tissue) and the fundus (1.04 +/- 0.54 v. 1.43 +/- 0.92 nmol/mg tissue, P < 0.05) in malnourished than in well-nourished control patients. Glutathione mucosal concentrations were decreased significantly in patients with NSAID-induced gastric bleeding compared with control patients (0.38 +/- 0.36 v. 1.12 +/- 0.56 nmol/mg tissue, P < 0.001), and the lowest glutathione levels were observed in malnourished patients (0.28 +/- 0.20 v. 0.48 +/- 0.15 nmol/mg tissue in well-nourished patients, not significant).

CONCLUSION

Malnutrition is associated with low levels of gastric glutathione. This may contribute to the severity and the onset of haemorrhage in NSAID-induced gastric ulcers.

Over-the-counter analgesics and antipyretics: a critical assessment

BACKGROUND

It is just 100 years since the introduction of aspirin to medicine. Since then, aspirin and its derivatives have been joined by acetaminophen, and the nonsteroidal anti-inflammatory drugs--ibuprofen, naproxen sodium, and ketoprofen--as the only over-the-counter (OTC) agents approved by the US Food and Drug Administration for the short-term treatment of pain, headache, dysmenorrhea, and fever. Recently the prescription use of aspirin has expanded to include a number of antiplatelet indications.

OBJECTIVE

The purpose of this paper is to review critically the history, mechanisms of action, efficacy, and tolerability of OTC analgesic and antipyretic products. Relatively new and potential future indications for these drugs are also discussed.

CONCLUSION

Although all of the OTC analgesic/antipyretic agents seem to share a common mechanism of prostaglandin inhibition, there are important differences in their pharmacology, efficacy, and side-effect profiles. Considering their often-unsupervised use, the risk-benefit ratio of this class of drugs has been extremely favorable. However, when used inappropriately, even these drugs pose significant risks to certain patient populations.

Upper gastrointestinal toxicity of alendronate

OBJECTIVE

Alendronate is rapidly gaining widespread use in the treatment of osteoporosis. However, recent postmarketing surveys and endoscopic studies suggest that its use may be associated with significant predictable esophageal and gastric mucosal toxicity, similar to that of aspirin and nonsteroidal anti-inflammatory drugs. Because treatment of osteoporosis may be needed in as many as 30% of all postmenopausal women, and considering that alendronate could be used in all postmenopausal women as prevention, definition of potential mucosal toxicity is crucial. Our aim was to study the upper gastrointestinal toxicity of alendronate in an age-appropriate female population using a clinically applicable dose (10 mg/day) to determine whether it causes predictable damage in the proximal gastrointestinal mucosa in a fashion similar to that seen with aspirin and nonsteroidal anti-inflammatory drugs.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial in 32 healthy female volunteers between the ages of 40 and 65 yr recruited by newspaper advertisement. Endoscopic mucosal abnormalities in the esophagus, stomach, and duodenum both before and after 1 month of treatment were scored and compared using validated endoscopic grading systems. Symptom scores before and after treatment were determined. Noninvasive measurements of gastrointestinal permeability were obtained before, during, and after treatment using sucrose and mannitol/lactulose urinary excretions.

RESULTS

Endoscopic scores before and after treatment with alendronate were not significantly different. Similarly, mean symptom scores in the alendronate group did not change significantly after treatment. There were no significant mucosal permeability changes in the stomach or small intestine after treatment.

CONCLUSION

Alendronate does not cause predictable esophageal, gastric, or duodenal mucosal damage when used as directed.

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.

Cyclooxygenase-2 specificity and its clinical implications

Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce pain and inflammation by inhibiting the synthesis of prostanoids. However, these drugs inhibit both cyclooxygenase-1 (COX-1), which is essential for the regulation of homeostasis in many tissues, as well as COX-2, which is an important mediator of pain and inflammation. Disruption of COX-1 enzymatic activity by NSAIDs leads to such side effects as interference with platelet functions and gastric ulcers. The recent development of COX-2-specific inhibitors, such as celecoxib, raises the possibility of relieving pain and inflammation with reduced risk of gastrointestinal complications. In Phase II and III studies, celecoxib has demonstrated efficacy in alleviating dental pain and the signs and symptoms of osteoarthritis and rheumatoid arthritis. This COX-2-specific inhibitor was also associated with a markedly lower rate of gastroduodenal injury than is seen typically with NSAIDs. Incidence of most adverse events (including gastrointestinal) and withdrawal rates resulting from adverse events with celecoxib were similar to placebo. Celecoxib appears to be both safe and effective in the treatment of osteoarthritis and rheumatoid arthritis. Its COX-2-specific inhibitory properties thus introduce the possibility of effective relief of arthritic and other types of pain and inflammation with less risk of the mechanism-based toxicities observed with conventional NSAIDs.

Preliminary study of the safety and efficacy of SC-58635, a novel cyclooxygenase 2 inhibitor: efficacy and safety in two placebo-controlled trials in osteoarthritis and rheumatoid arthritis, and studies of gastrointestinal and platelet effects

OBJECTIVE

To investigate the efficacy and safety of SC-58635 (celecoxib), an antiinflammatory and analgesic agent that acts by selective cyclooxygenase 2 (COX-2) inhibition and is not expected to cause the typical gastrointestinal (GI), renal, and platelet-related side effects associated with inhibition of the COX-1 enzyme.

METHODS

Four phase II trials were performed: a 2-week osteoarthritis efficacy trial, a 4-week rheumatoid arthritis efficacy trial, a 1-week endoscopic study of GI mucosal effects, and a 1-week study of effects on platelet function.

RESULTS

The 2 arthritis trials identified SC-58635 dosage levels that were consistently effective in treating the signs and symptoms of arthritis and were distinguished from placebo on standard arthritis scales. In the upper GI endoscopy study, 19% of subjects receiving naproxen (6 of 32) developed gastric ulcers, whereas no ulcers occurred in subjects receiving SC-58635 or placebo. The study of platelet effects revealed no meaningful effect of SC-58635 on platelet aggregation or thromboxane B2 levels, whereas aspirin caused significant decreases in 2 of 3 platelet aggregation measures and thromboxane B2 levels. In all 4 trials, SC-58635 was well tolerated, with a safety profile similar to that of placebo.

CONCLUSION

SC-58635 achieves analgesic and antiinflammatory efficacy in arthritis through selective COX-2 inhibition, without showing any evidence of 2 of the toxic effects of COX-1 inhibition associated with nonsteroidal antiinflammatory drugs.

Effects of nonsteroidal antiinflammatory drugs on platelet function and systemic hemostasis

Aspirin and nonaspirin nonsteroidal antiinflammatory drugs (NSAIDs) inhibit platelet cyclooxygenase, thereby blocking the formation of thromboxane A2. These drugs produce a systemic bleeding tendency by impairing thromboxane-dependent platelet aggregation and consequently prolonging the bleeding time. Aspirin exerts these effects by irreversibly blocking cyclooxygenase and, therefore, its actions persist for the circulating lifetime of the platelet. Nonaspirin NSAIDs inhibit cyclooxygenase reversibly and, therefore, the duration of their action depends on specific drug dose, serum level, and half-life. The clinical risks of bleeding with aspirin or nonaspirin NSAIDs are enhanced by the concomitant use of alcohol or anticoagulants and by associated conditions, including advanced age, liver disease, and other coexisting coagulopathies.

Greater curvature antral flattening: a radiologic sign of NSAID-related gastropathy

We have occasionally encountered patients on nonsteroidal antiinflammatory drugs (NSAIDs) in whom double contrast barium studies revealed persistent flattening and stiffening of the distal greater curvature of the stomach. We therefore performed a study to determine the frequency of this finding in patients with NSAID-related gastropathy. Twenty-one cases of erosive gastritis, gastric ulcers, and/or gastric scarring associated with a known history of NSAID use were reviewed by two radiologists who made a joint decision regarding the presence or absence of greater curvature antral flattening. This finding was seen radiographically in five of the 21 patients (24%). Four of the five patients with antral flattening had associated erosions or ulcers in the gastric antrum. The remaining patient had antral flattening as an isolated finding. Our experience suggests that flattening of the greater curvature of the distal antrum, particularly if associated with erosive gastritis or gastric ulcers, is a useful radiologic sign of NSAID-related gastropathy.

Side effects of nonsteroidal anti-inflammatory drugs on the small and large intestine in humans

BACKGROUND

It is not widely appreciated that nonsteroidal anti-inflammatory drugs (NSAIDs) may cause damage distal to the duodenum. We reviewed the adverse effects of NSAIDs on the large and small intestine, the clinical implications and pathogenesis.

METHODS

A systematic search was made through Medline and Embase to identify possible adverse effects of NSAIDs on the large and small intestine.

RESULTS

Ingested NSAIDs may cause a nonspecific colitis (in particular, fenemates), and many patients with collagenous colitis are taking NSAIDs. Large intestinal ulcers, bleeding, and perforation are occasionally due to NSAIDs. NSAIDs may cause relapse of classic inflammatory bowel disease and contribute to serious complications of diverticular disease (fistula and perforation). NSAIDs may occasionally cause small intestinal perforation, ulcers, and strictures requiring surgery. NSAIDs, however, frequently cause small intestinal inflammation, and the associated complications of blood loss and protein loss may lead to difficult management problems. The pathogenesis of NSAID enteropathy is a multistage process involving specific biochemical and subcellular organelle damage followed by a relatively nonspecific tissue reaction. The various possible treatments of NSAID-induced enteropathy (sulphasalazine, misoprostol, metronidazole) have yet to undergo rigorous trials.

CONCLUSIONS

The adverse effects of NSAIDs distal to the duodenum represent a range of pathologies that may be asymptomatic, but some are life threatening.

Non-steroidal anti-inflammatory drug-induced gastropathy: a comparative endoscopic and histopathological evaluation of the effects of tenoxicam and diclofenac

A 4-week double-blind study compared the potential for 20 mg/day tenoxicam or 100 mg/day diclofenac sodium to induce gastropathy in 36 patients with joint disease and assessed the influence of gastric colonization by Helicobacter pylori. Endoscopic assessment at the end of 4 weeks indicated that the mucosa was normal in 79% of tenoxicam-treated patients and 59% of diclofenac-treated patients. Only 5% of patients in the tenoxicam group developed severe gastroduodenitis (> 11 haemorrhages or erosions) compared with 18% in the diclofenac group. Histological evaluation indicated that 58% and 47%, respectively, of tenoxicam-treated and diclofenac-treated patients retained normal mucosa after treatment. Diclofenac treatment was discontinued in two patients, due to a duodenal ulcer or severe erosive gastritis. Overall, 5/14 patients with moderate to severe colonization with Helicobacter pylori developed severe chronic active gastritis or ulceration, compared with the 1/22 patients in whom colonization was either absent or mild (P = 0.02). Tenoxicam and diclofenac did not show major differences in terms of gastrointestinal safety, although the trends favoured tenoxicam. The presence of severe colonization of the gastric mucosa with Helicobacter pylori appears to be an important factor for development of severe gastritis or ulceration.

Long-term nonsteroidal anti-inflammatory drug use and gastroduodenal injury: the role of Helicobacter pylori

To evaluate the association of Helicobacter pylori infection with gastroduodenal ulceration and symptoms in rheumatoid arthritis patients chronically ingesting nonsteroidal anti-inflammatory drugs (NSAIDs), a population-based study was performed. Residents of Olmsted County, Minnesota, and surrounding counties, 40 years of age and over with active rheumatoid arthritis taking therapeutic dose of NSAIDs daily for 6 months or more were evaluated (n = 50). An endoscopic score from 0 to 5 was assigned and independently confirmed. Biopsies were obtained from the antrum and gastric body for the presence of H. pylori. A symptom score based on the frequency and severity of dyspeptic symptoms was calculated. Substantial mucosal injury (greater than or equal to grade 2) was observed at endoscopy in 33 patients (66%); 14 (28%) had chronic ulcers. Eleven of the community patients with rheumatoid arthritis (22%) were H. pylori positive; adjusting for age, the prevalence of H. pylori was not significantly different to that in 67 health controls (25%). One or more upper gastrointestinal symptoms were reported by 19 of the community patients (38%). Adjusting for age, community rheumatoid arthritis patients with H. pylori were not more likely to have visible mucosal damage or dyspepsia, but were significantly more likely to have histological gastritis (P less than 0.01). The results suggest that, in primarily asymptomatic persons from the community with rheumatoid arthritis taking daily NSAIDs for 6 months or more, H. pylori infection is not related to the severity of visible mucosal injury.

Nonsteroidal anti-inflammatory gastropathy: from theory to practice

The success of nonsteroidal anti-inflammatory drugs in managing joint inflammation and pain has come at the cost of impressive side effects, particularly in the gastrointestinal tract. This manuscript reviews the magnitude of the problem, the risk factors, and presentation of nonsteroidal gastropathy. It also presents some points in the prevention and management of the disorder.

Endoscopic comparison of cimetidine and sucralfate for prevention of naproxen-induced acute gastroduodenal injury. Effect of scoring method

Nonsteroidal antiinflammatory drug-induced gastroduodenal mucosal damage observed endoscopically is usually categorized as hemorrhages, erosions, or ulcerations. We undertook this study to determine whether the injury produced by a commonly prescribed NSAID, naproxen, could be reduced by cotherapy with sucralfate or cimetidine and to determine how dependent the differences in the degree of protection against mucosal injury measured were on the scoring system used. Four groups of 20 healthy volunteers with endoscopically normal gastric and duodenal mucosa received naproxen (500 mg twice a day) plus cimetidine (300 mg four times a day or 400 mg twice a day), sucralfate (1 g four times a day), or placebo for seven days. After seven days of therapy, a second endoscopy was performed. Separate scoring systems were used for the presence of hemorrhages, erosions, and a combination of both types of injury. There were significantly fewer mucosal hemorrhages present when naproxen and cimetidine were administered than when naproxen was administered with placebo or sucralfate (placebo vs 300 mg cimetidine, P = 0.04, and placebo vs 400 mg cimetidine, P = 0.006, placebo vs sucralfate, P = 0.26). Both cimetidine dosages resulted in significantly fewer hemorrhages than were present following cotherapy of naproxen and sucralfate (P less than 0.05). In contrast, there was no discernible difference in the mucosal injury between placebo and any drug or between any two active therapies when the injury was evaluated based on the presence of gastric erosions.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclooxygenase inhibition with indomethacin increases human duodenal mucosal response to prostaglandin E1

In humans, prostaglandins of the E1 class stimulate duodenal mucosal bicarbonate secretion, whereas the cyclooxygenase inhibitor, indomethacin, decreases both mucosal PGE2 and bicarbonate production. The purpose of this study was to determine whether a synthetic prostaglandin E1, enisoprost, diminished the inhibitory effects of indomethacin on mucosal bicarbonate secretion. In seven healthy subjects the proximal 4 cm of duodenum was isolated by occluding balloons. The isolated test segment was perfused with 154 mM NaCl (2 ml/min, 37 degrees C). Each subject participated in four separate tests in random order. Indomethacin, 50 mg, or placebo was given 13 and 1 hr before testing. After measuring basal bicarbonate secretion, either 100 micrograms of prostaglandin E1 or placebo (in 154 mM NaCl) was perfused into the test segment over 30 min. As anticipated, PGE1 significantly increased duodenal mucosal bicarbonate secretion, and indomethacin decreased resting bicarbonate secretion. Indomethacin pretreatment significantly enhanced (P less than 0.03) the mucosa's response to PGE1 compared to PGE1 alone. These results further support the observations that endogenous prostaglandins, in part, regulate human proximal duodenal bicarbonate secretion. Furthermore, suppression of endogenous prostaglandin generation results in an increased sensitivity of the duodenal mucosa to PGE1.

Effects of food and sucralfate on the pharmacokinetics of naproxen and ketoprofen in humans

Compliance to nonsteroidal anti-inflammatory drug therapy can be compromised by gastrointestinal side effects. To overcome this problem, food, antacid, or sucralfate are often co-administered with nonsteroidal anti-inflammatory drugs. Three studies were conducted on three groups of 12 volunteers in order to determine the influence of food or sucralfate on the pharmacokinetics of naproxen and ketoprofen. In a crossover experimental design, the first group received a single dose (50 mg) of ketoprofen with and without sucralfate (2 g). The second group received single (100 mg) and multiple (100 mg twice daily for 5 days) doses of enteric-coated ketoprofen with and without food. The third group received single (500 mg) and multiple (500 mg twice daily) doses of naproxen with and without sucralfate. Multiple blood samples were drawn and analyzed by high-pressure liquid chromatography. Short- and long-term pharmacokinetic parameters were determined. Results in group 1 showed that neither ketoprofen bioavailability nor maximal plasma concentration and time to reach maximal concentration were affected by the administration of sucralfate. However, in group 2 absorption of ketoprofen was markedly affected by food. In the presence of food, maximal plasma concentration decreased from 10.7 to 6.3 micrograms/ml after single-dose administration and 12.1 to 8.0 micrograms/ml after multiple-dose administration. The time to reach maximal plasma concentration was also modified by food, increasing from 2.8 to 7.1 hours after single-dose and 2.8 to 7.6 hours after multiple-dose administration. Food caused a significant decrease in the bioavailability of ketoprofen (over 40 percent) following both single-dose (23.8 versus 13.1 micrograms.hour/ml) and multiple-dose (29.3 versus 16.8 micrograms.hour/ml) administration. Results obtained in group 3 showed that sucralfate reduced the absorption rate constant of naproxen, from 1.7 to 1.2 hours-1 and from 1.5 to 0.7 hour-1 following single- and multiple-dose administration, respectively. However, bioavailability of naproxen was not affected by sucralfate administration. Overall, these studies have shown that sucralfate does not alter the pharmacokinetics of naproxen and ketoprofen; the amount of drug absorbed remains constant. However, plasma concentrations of ketoprofen after single- and multiple-dose administration were greatly affected by food, with a decrease of greater than 40 percent in bioavailability.

Etodolac, a new nonsteroidal anti-inflammatory drug: gastrointestinal microbleeding and endoscopic studies

A review of the literature is presented on the gastrointestinal effects of etodolac, a new nonsteroidal anti-inflammatory drug (NSAID), as evaluated in both microbleeding and endoscopic studies. In four microbleeding studies, gastrointestinal blood loss in healthy subjects was estimated by a 51Cr-erythrocyte labeling method before drug treatment, after 7 days of treatment with NSAIDs including etodolac, and 1 week after the last day of treatment. In these 7-day studies, the gastrointestinal blood loss seen with etodolac (600 to 1200 mg/day) was similar to that seen with placebo and significantly (p less than 0.05) less than that seen with aspirin (2600 mg/day), naproxen (750 mg/day), ibuprofen (2400 mg/day), or indomethacin (200 mg/day). Naproxen, ibuprofen, and indomethacin caused mean daily blood losses in excess of 1 ml/day over baseline values. The increase with aspirin was 4 to 5 ml/day. In contrast, the greatest mean daily increase in blood loss with etodolac therapy was 0.2 ml. In a 4-week study of etodolac (600 and 1000 mg/day) and piroxicam (20 mg/day) given to patients with osteoarthritis or rheumatoid arthritis, blood loss seen with etodolac was comparable to that seen with placebo and significantly less than that seen with piroxicam. Gastrointestinal irritation was also assessed by endoscopy after 1 week of NSAID or placebo treatment. Endoscopy scores after etodolac treatment (up to 1200 mg/day) were similar to scores at baseline and after placebo and were significantly lower than scores following treatment with aspirin (3900 mg/day), indomethacin (200 mg/day), ibuprofen (2400 mg/day), or naproxen (100 mg/day). The effects of etodolac (600 or 1000 mg/day) and diclofenac (150 mg/day) were not different from each other or from baseline. These data indicate that etodolac, in these studies, did not cause clinically significant gastrointestinal microbleeding or visible gastric injury. By the criteria used in these studies, etodolac is less irritating to the gastrointestinal tract than aspirin, indomethacin, ibuprofen, naproxen, or piroxicam, and compares favorably with diclofenac.

A review of gastric ulcer and gastroduodenal injury in normal volunteers receiving aspirin and other non-steroidal anti-inflammatory drugs

Studies in normal volunteers from our laboratory and by other investigators have demonstrated that non-steroidal anti-inflammatory agents (NSAIDs) can significantly damage the gastroduodenal mucosa. This damage is maximal with plain and buffered aspirin products. The injury produced by non-aspirin NSAIDs in anti-inflammatory doses is less than with aspirin but depends primarily on the dosages used. Pro-drugs and enteric-coated aspirin tend to produce less injury. The incidence of gastric ulcer in 1064 normal volunteers studied in our laboratory over a period of 7 years is reviewed. Seventy-two (6.7%) normal subjects developed a gastric ulcer after 7 days of therapy with anti-inflammatory doses of these drugs. The largest number of ulcers were seen with plain and buffered aspirin, and the lowest number with the lower anti-inflammatory doses of the non-aspirin NSAIDs.

Clinical differences among nonsteroidal antiinflammatory drugs: implications for therapeutic substitution in ambulatory patients

The practice of therapeutic substitution, i.e., replacing one drug with another chemically different drug from the same therapeutic class, represents an important therapeutic modification with potential clinical significance far beyond that of generic substitution. Adverse consequences following therapeutic substitution of nonsteroidal antiinflammatory drugs (NSAID) is of special concern because of substantial differences among these agents in pharmacokinetic, pharmacological, and clinical properties. Therapeutic substitution of NSAID for ambulatory patients may result in compromised clinical outcome because (1) patient response is unpredictable and selection of the optimal agent must be tailored for each patient; (2) substantial differences exist in adverse reaction profiles; (3) drug interaction studies are lacking; and (4) selection of an agent must be individualized to ensure compliance with the dosing regimen. Cost savings achieved through therapeutic substitution of NSAID may be lost by additional overall treatment costs due to adverse reactions or suboptimal therapy. The occurrence of adverse or suboptimal effects in ambulatory patients is more likely if NSAID are substituted without full knowledge of the patient's medical history and clinical status. Communication between the pharmacy and prescribing physician regarding a patient's specific needs is essential for rational substitution among NSAID.

Double-blind, placebo-controlled endoscopic comparison of the mucosal protective effects of misoprostol versus cimetidine on tolmetin-induced mucosal injury to the stomach and duodenum

Ninety normal volunteers were entered into a double-blind, placebo-controlled study to compare the efficacy of misoprostol (200 micrograms q.i.d.) vs. cimetidine (300 mg q.i.d.) in protecting the gastric and duodenal mucosa from tolmetin-induced (400 mg q.i.d.) injury. After 6 days of treatment, the degree of mucosal injury between treatments was compared by endoscopy, using a predetermined rating scale of 0 (normal mucosa) to 4+ (greater than 25 hemorrhages or erosions or an invasive ulcer). Utilizing a score of less than or equal to 2+ (2-10 hemorrhages or erosions) as a therapeutic success, the overall success rates were 8/30 (26.7%) for placebo, 19/30 (63.3%) for cimetidine, and 27/29 (93.1%) for misoprostol (p less than 0.001). Pairwise comparisons were also significant: misoprostol vs. placebo (p less than 0.001), misoprostol vs. cimetidine (p = 0.006), and cimetidine vs. placebo (p = 0.004). A separate analysis of the gastric scores alone revealed success rates identical to those in the overall evaluation; however, success rates in the duodenum for both misoprostol (29/29) and cimetidine (29/30) were extremely high and did not differ. It is concluded that misoprostol is highly effective and significantly better than cimetidine in protecting the gastric mucosa from tolmetin-induced injury; however, both agents were highly protective in the duodenum.

Effects of nonsteroidal, antiinflammatory drugs on gastrointestinal injury and prostanoid generation in healthy volunteers

A new nonsteroidal, antiinflammatory drug, carprofen, was compared with indomethacin as to their effects on mucosal injury and prostanoid biosynthesis. A prospective, double-blind endoscopy study was performed in 40 healthy adults. After baseline normal endoscopy, 20 subjects were randomly assigned to either indomethacin (25 mg four times daily) or carprofen (150 mg twice daily) for eight days and re-endoscoped. Urinary and gastric mucosal prostaglandin generation, respectively, of PGE2 and PGF2 alpha, and PGE and 6-keto-PGF1 alpha was determined. Minor subjective symptoms occurred in six of 20 indomethacin (including four of eight with gastrointestinal injury) and in three of 20 carprofen subjects. Indomethacin and carprofen reduced gastric and urinary prostaglandin synthesis to a similar degree. Gastrointestinal injury was present in eight of 20 indomethacin and in none of 20 carprofen subjects. This study fails to establish a relationship between duodenal mucosal lesions and gastric prostanoid generation and confirms the lack of correlation between indomethacin-induced duodenal injury and subjective symptomatology. Carprofen appears to produce less objective damage in the upper gastrointestinal tract than indomethacin at comparable clinical doses.

Ulcerogenic drugs and upper gastrointestinal bleeding

Aspirin and other NSAIDs are drugs for which the causal association with major gastrointestinal bleeding has not been adequately or conclusively demonstrated, although a certain degree of correlation is very likely. For aspirin ingestion in particular the increased risk is confined to patients taking the drug at heavy and regular dosages (less than 1% of users), and can be reduced further by the use of enteric-coated formulations. For non-aspirin NSAIDs, the relative risk of GI bleeding after repeated and prolonged exposure (in comparison to controls) has been quantified between 1.5 and 2.7, which is a small but significant figure, and it is increased by the age of the patients, by the duration of treatment and by the dose of drug. No consistent causal relationship can be found between major GI bleeding (or other major peptic ulcer complications) and steroids or other 'ulcerogenic' drugs. The therapy of drug-induced (or drug-associated) GI bleeding is probably not different from the usual treatment of upper GI haemorrhage. As far as the treatment of drug-associated gastroduodenal mucosal damage is concerned, it appears that with mucoprotective agents or H2 antagonists the healing rates of peptic ulcers is slower than observed in non-drug-associated disease. Prophylactic treatment with prostaglandins has only been proposed; and prophylactic treatment with H2 antagonists has been disappointing.

Clinical spectrum of the upper gastrointestinal effects of nonsteroidal anti-inflammatory drugs. Natural history, symptomatology, and significance

Nonsteroidal anti-inflammatory drugs (NSAIDs) relieve rheumatic pain and are in extensive use. Symptomatic complications of NSAIDs requiring the discontinuation of their use occur in 2 to 10 percent of patients with rheumatic diseases in sharp contrast to the common asymptomatic problems of gastroduodenal erosions, ulcerations, and bleeding, with resulting anemia in more than 40 percent of these patients. Opinions concerning the clinical significance of these complications are not uniform. The natural history of the effects of NSAIDs on the gastroduodenal mucosa reveals a sequence of initial subepithelial hemorrhage over a 24-hour period followed by gastroduodenal erosions and ulcerations in the next two weeks. From one week to three months, gastroduodenal erosions and ulcerations disappear in about half of the patients as an adaptation to continuing NSAID ingestion occurs. Hemorrhage may occur at any time in most patients and in a small minority (1 percent) it is massive. Non-aspirin NSAIDs (NANSAIDs) exhibit significantly fewer complications than do aspirin. These complications, however, demand considerable clinical attention and are ordered in a constant hierarchy, suggesting variable risks of complications among agents. NSAIDs are a blessing for those who have chronic pain, but that blessing does not prevent significant asymptomatic complications in the same patients. Prophylaxis for high-risk groups, such as women over the age of 65 years, should be subjected to study.

Damage and protection of the human gastric mucosa. A multiparameter assessment

Studies in animals and humans have indicated that endogenous prostaglandins as well as synthetic prostaglandin analogues can prevent gastric mucosal damage induced by various agents. Methods were developed to assess induced damage and the effects of potentially protective agents (synthetic prostaglandin analogues and the histamine [H2]-receptor antagonist cimetidine) on the human gastric mucosa by measuring ion fluxes and transmucosal potential difference, as well as by observations with gastrointestinal endoscopy. Commonly ingested agents, such as aspirin, 1,300 mg, and 20 percent ethanol increased hydrogen ion and sodium ion fluxes, decreased potential difference, and caused gross mucosal damage, as observed by endoscopy. Conversely, acetaminophen, 2,600 mg, and 10 percent ethanol did not have any significant effects. Hyperosmolar solutions (1,800 and 3,600 mOsm/kg) also produced acute damage. Sodium taurocholate (10 mmol/liter) when instilled into the stomach, either at pH 1.1 or 7.0, produced both functional and structural damage. When given as a single dose, neither 15(R)15-methyl PGE2 nor the synthetic PGE1 analogue, misoprostol, prevented mucosal damage induced by aspirin and taurocholate (pH 1.1), respectively. Cimetidine, 400 mg orally, however, did reduce aspirin-induced mucosal damage, and this effect was independent of gastric acid inhibition.

Management of NSAID-induced gastrointestinal lesions

Mucosal lesions in the g.i. tract due to ASA and other nonsteroidal anti-inflammatory drugs are well-known in clinical practice. Though the gastroduodenal mucosa is the area most commonly investigated, several recent reports focus on lesions in the small and large intestine as well. Despite considerable efforts in the field, none of the new substances developed in the past few years have proven convincingly superior to existing drugs. Instead, other approaches are being evaluated: Bypassing of the gastroduodenal mucosa through enteric coating and slow release formulations have been suggested, but the possibility of transferring the deleterious effects to distal parts of the gastrointestinal tract by such formulation modifications calls for extensive evaluation of this area, before these formulations can be applauded as advantageous in this group of patients. Co-administration of protective substances has also been advocated, and, despite somewhat contradictory results, protection has been reported by H2-antagonists alone or in combination with antacids, as well as by cytoprotective agents like Sucralfate, and prostaglandin analogues.

Cimetidine decreases aspirin-induced gastric mucosal damage in humans

Aspirin induces gastric mucosal damage in animals and humans. The purpose of this study was to examine whether cimetidine protects the human gastric mucosa from acute aspirin-induced damage. Eight healthy subjects were studied on 4 separate days. Cimetidine, 400 mg, or placebo was given orally 1 hour before initial endoscopy. The stomach was isolated and atropine given to suppress basal acid secretion. Each study consisted of four 15 min periods during which an acidic test solution was instilled into the stomach. During the second period only, either aspirin (1300 mg, 36 mmol) or control for aspirin (36 mmol HCl) was added to the test solution. Ion fluxes and gastric mucosal potential difference were measured, and endoscopy performed following each test. After placebo, aspirin significantly altered hydrogen ion flux and potential difference versus basal and control. Cimetidine decreased the damaging effect of aspirin. Endoscopic scores increased after aspirin plus placebo, whereas they remained unchanged after aspirin plus cimetidine. Therefore, cimetidine decreased aspirin-induced gastric mucosal damage in humans. As gastric acidity was identical during all studies, the effect of cimetidine was independent of gastric acid secretion.

Effects of concurrent sucralfate administration on pharmacokinetics of naproxen

Sucralfate has been reported to protect the gastroduodenal mucosa against a variety of agents and is known to adsorb bile salts. Since gastrointestinal side effects can seriously compromise the efficacy of nonsteroidal anti-inflammatory drug therapy, and since it seems reasonable to assume that sucralfate may adsorb nonsteroidal anti-inflammatory drugs, the influence of sucralfate on the pharmacokinetic parameters of naproxen was assessed in 12 healthy volunteers. To do so, the pharmacokinetic profile of naproxen, administered alone or with sucralfate, singly or repeatedly (twice daily for five days), was compared. No significant difference was observed with any pharmacokinetic parameter between the single administration of naproxen alone or with sucralfate. However, a significantly lower maximum plasma concentration was attained with the repeated administration of naproxen in combination with sucralfate, compared with the repeated administration of naproxen alone. When single- and multiple-dose administration were compared, significant differences were observed in the maximum plasma concentration and the cumulative area under the curve. These results suggest an accumulation of naproxen after five days' administration. This accumulation, however, is not altered by the administration of sucralfate. The results of this study suggest that when naproxen is administered with sucralfate, only a delay in naproxen's absorption may occur, confirmed by a lower maximum plasma concentration, a longer time to reach the maximum plasma concentration, a similar elimination half-life, and equivalence in bioavailability. The clinical importance of such a delay has yet to be proved; however, it is unlikely that the clinical efficacy of naproxen will be altered, since the amount of drug absorbed remains the same.

Sucralfate treatment of nonsteroidal anti-inflammatory drug-induced gastrointestinal symptoms and mucosal damage

In a randomized, double-blind trial, sucralfate therapy, 1 g four times daily, was compared with placebo in 143 symptomatic patients to assess the treatment of gastrointestinal symptoms and gastric mucosal damage associated with nonsteroidal anti-inflammatory drugs (NSAIDs). All patients followed a fixed regimen of NSAIDs, were assigned to one of two groups based on the presence or absence of gastric erosions at baseline endoscopy, and were then assigned randomly to receive sucralfate or placebo for four weeks. Patients were then followed for up to six months while receiving open-label sucralfate 1 g twice daily to up to 1 g four times daily. After four weeks of double-blind therapy, patients taking either nonsalicylate NSAIDs or long half-life NSAIDs and who were treated with sucralfate experienced a significant reduction in both peptic symptom frequency and intensity (p less than 0.03) as compared with patients receiving placebo. Sucralfate-treated patients with baseline endoscopic lesions showed a significant reduction in lesion scores (p less than 0.005) at four weeks as compared with baseline, whereas no improvement was observed in gastric mucosal lesions of patients given placebo. Long-term sucralfate therapy resulted in continued improvement in gastrointestinal symptoms and gastric lesion scores in patients receiving all types of NSAIDs. The results indicate that sucralfate used in conjunction with NSAIDs may allow patients to continue therapy by relieving gastrointestinal symptoms and mucosal damage associated with NSAID therapy.

Single dose pharmacokinetics of ketoprofen, indomethacin, and naproxen taken alone or with sucralfate

The effects of sucralfate on the rate and extent of absorption of ketoprofen, indomethacin, and naproxen were investigated in healthy volunteers. Six volunteers each received sucralfate (2 g) half an hour before a ketoprofen (50 mg) capsule, and, on another occasion, a ketoprofen (50 mg) capsule alone according to a 2 X 2 Latin square pattern of administration. The same design was used for studies with indomethacin (50 mg) capsules and naproxen (500 mg) tablets. Sucralfate decreased significantly (p less than 0.05) the maximum plasma concentrations (Cmax) of ketoprofen, indomethacin, and naproxen. Although the time necessary to attain Cmax (tmax) for the three drugs tended to increase, only for indomethacin was this increase significant. Sucralfate decreased significantly the rate of absorption (ka) of naproxen and indomethacin, but not that of ketoprofen; it had no significant effect on the elimination half-life and area under the plasma concentration as a function of time curves (AUC0----infinity) of the three drugs. Sucralfate thus decreases the Cmax and increases the tmax of ketoprofen, indomethacin, and naproxen without affecting their bioavailabilities.

A chronobiologic approach to ethanol and acidified aspirin injury of the gastric mucosa in the rat

Several models of erosive peptic disease have used drug-induced lesions to examine protective mechanisms of the gastric mucosa. Physiological processes such as acid secretion, motility, or epithelial cell turnover have circadian rhythms which may modulate the susceptibility of the gastric mucosa to injury. In this review are described recent studies which demonstrated that susceptibility to gastric mucosal injury by acidified aspirin and absolute ethanol varied with the phases of the light-dark cycle. Acidified aspirin caused significantly more gastric mucosal lesions when administered early in the light phase compared to administration early in the dark phase. The differences in susceptibility were not altered by pretreatment conditions such as immobilization or length of the fasting period. Absolute ethanol also caused significantly greater gastric mucosal injury when administered in the light than in the dark phase, but this difference was only evident in rats immobilized during the pretreatment fasting period. Further studies are needed to correlate circadian susceptibility to drug-induced gastric mucosal injury with physiological defense mechanisms. Careful attention to circadian timekeeping may allow us to refine therapy to optimize physiological defense mechanisms in the stomach.

It is wise to prescribe NSAIDs with modern gastroprotective agents?

The administration of non-steroidal anti-inflammatory drugs (NSAIDs) leads to mucosal lesions in the upper gastrointestinal tract. Furthermore, NSAIDs increase the risk of ulcer bleeding and perforation, but the overall risk of fatal complications is relatively small (about 21 per one million prescriptions). Therefore, in asymptomatic patients, it is not justified to prescribe NSAIDs together with gastroprotective agents. The following recommendations can be given with respect to the management of peptic lesions in patients taking NSAIDs: (i) Fibre endoscopy should be performed even when there are relatively mild symptoms since mucosal lesions in rheumatic patients under NSAIDs produce minor or no symptoms. (ii) "Modern" NSAIDs might produce less gastric lesions than aspirin. (iii) Rheumatic patients with peptic disorders should be treated with an H2-antagonist. (iv) After complications such as ulcer bleeding or after rapid recurrence of peptic lesions, maintenance treatment with an H2-antagonist is advisable.

Effect of acetaminophen on human gastric mucosal injury caused by ibuprofen

Acetaminophen has been proposed as an agent which protects the gastric mucosa against damage induced by aspirin and other non-steroidal anti-inflammatory agents. In order to evaluate this proposal further, 45 normal human volunteers were divided into three groups (n = 15); group one received ibuprofen 2400 mg daily (600 mg qid); group two received acetaminophen 3900 mg daily (975 mg qid) and group three received both drugs at the same dosages. There was no significant difference in the mucosal injury scores noted at endoscopy between the ibuprofen and the ibuprofen-acetaminophen group. The acetaminophen group had virtually no observed mucosal injury and this was statistically significant in comparison with the other groups (p less than 0.01). We conclude that contrary to previously reported studies using single doses of aspirin, acetaminophen failed to decrease the mucosal injury seen with ibuprofen when given for a period of seven days in combination with acetaminophen.

A double-blind study of prophylactic effect of misoprostol on lesions of gastric and duodenal mucosa induced by oral administration of tolmetin in healthy subjects

Tolmetin, a nonsteroidal antiinflammatory drug, is known to induce edema, submucosal hemorrhage, and erosions of the gastrointestinal tract when administered at recommended doses. The purpose of our study was to determine whether misoprostol prevented or reduced the severity of duodenal and gastric mucosal injury induced by tolmetin. Following endoscopic screening, 60 healthy male and female subjects were assigned at random to one of two treatment groups. One group was treated with tolmetin (2000 mg/day, in four divided doses) and misoprostol (200 micrograms four times daily); the other with tolmetin and placebo. Both drugs were administered for six and a quarter days. On the seventh day, 2 hr after the last dose, an endoscopic examination of the gastric and duodenal mucosa was repeated, and the results graded. Subjects with 10 or fewer hemorrhages or erosions were considered treatment successes; those with 11 or more erosions, plus any other lesions, were considered treatment failures. A total of 59 subjects completed the study. One withdrew because of an unsuspected pregnancy. In regard to the gastric mucosa, seven of 29 (24%) placebo subjects were considered treatment successes. In the misoprostol group, 27 of 30 (90%) were treatment successes. This difference is statistically significant at the P less than 0.0001 level. The overall damage to the duodenal mucosa caused by tolmetin is less than that to the gastric mucosa, with the misoprostol-treated subjects having significantly less damage than the placebo subjects (P less than 0.001). Side effects were common in both groups, but almost all were mild, gastrointestinal in origin, and did not require treatment or withdrawal from the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastrointestinal intolerance and bleeding with non-narcotic analgesics

Aspirin and paracetamol (acetaminophen) are the most commonly used minor analgesics, but their effects on the gastrointestinal tract differ widely. The effects of other nonsteroidal anti-inflammatory drugs (NSAIDs), including phenylbutazone, are intermediate. Aspirin is significantly associated with major upper gastrointestinal haemorrhage, whereas paracetamol is not. Short term use of aspirin produces erythema, erosions and occasionally ulcers; paracetamol does not, while other NSAIDs do so to varying degrees. Chronic gastric ulcer is linked to aspirin intake in patients with rheumatic disease, and epidemiologically in all heavy aspirin users. In only one epidemiological study was a paradoxical significant association reported between paracetamol intake and chronic gastric ulcer. Faecal occult blood loss is increased in most regular aspirin users but not in those taking paracetamol. Although formal studies in children have apparently not been made, in isolated small clinical series it has been reported that gastrointestinal bleeding and anaemia do occur in the paediatric age group after the use of aspirin. Pathophysiologically, aspirin alters the gastric mucosal barrier to hydrogen ions and lowers gastric potential difference; paracetamol has no effect on these parameters. Such changes correlate ultrastructurally with damage in surface epithelial cells and microerosions after the use of aspirin, but not after the use of paracetamol. Aspirin and other NSAIDs cause a dramatic reduction in the ability of gastric mucosa to generate protective prostaglandins; however, paracetamol also reduces prostaglandins. Other postulated mechanisms of aspirin damage include reduction in gastric mucosal secretion, reduction in bicarbonate output, and alteration of cell turnover. Because damage to gastric mucosa by aspirin and NSAIDs is often 'silent', the clinician needs a high level of suspicion and awareness regarding this problem. In patients prone to gastric damage, or in those with a past history of aspirin-induced gastric damage, paracetamol is the drug of choice when a minor, non-inflammatory problem requires an analgesic.

What's new in steroid and nonsteroid drug effects on gastroduodenal mucosa?

A survey is given on the damaging effect of acetylsalicylic acid, other nonsteroidal antiinflammatory drugs and corticosteroids on the gastroduodenal mucosa. The results of blood loss studies and endoscopic investigations are reviewed. Also, the histologic aspects of such damage are discussed. Modern concepts of the pathophysiology of these lesions stress the cytoprotective role of endogenous prostaglandins. Epidemiologic data strongly support an association between frequent and heavy intake of acetylsalicylic acid and gastric ulcer as well as gastrointestinal bleeding, whereas the association with duodenal ulcers is far less clearly established. Conclusive evidence is currently unavailable proving the superiority of other nonsteroidal antiinflammatory drugs in this regard. The ulcerogenic potency of corticosteroids at least in the small or medium dose range probably has been overstated in the past. Intensive ulcer therapy making use of H2 receptor antagonists often allows healing of small ulcers with a diameter up to 1 cm despite continued treatment with low dose corticosteroids or nonsteroidal antiinflammatory drugs, whereas continuation of these drugs is associated with very poor healing in ulcers larger than this size. The danger of perforation has to be taken into consideration.

Certain nonsteroidal antiinflammatory drugs and hospitalization for upper gastrointestinal bleeding

In this follow-up study we attempted to estimate the risk of hospitalization for upper gastrointestinal bleeding (exclusive of bleeding from duodenal ulcer) caused by taking certain nonsteroidal antiinflammatory drugs (NSAIDs) in people below the age of 65 years. The final figures represent our best estimate, taking into account all of the available information, and suggest that NSAIDs (excluding aspirin) rarely cause gastrointestinal bleeding from the stomach that requires hospitalization in this age group. A formal analysis of the data according to classic techniques was not feasible since numerous important confounding factors could not be controlled. Indeed, the results indicated that such formal analysis is unnecessary. The data as they stand are of considerable value in providing a reasonable estimate of attributable risk for the drugs studied.

Reduction in gastric mucosal hemorrhage and ulceration with chronic high-level dosing of enteric-coated aspirin granules two and four times a day

When administered on a chronic high-dosage regimen, enteric-coated aspirin granules produced significantly less gastric damage than plain aspirin or aspirin-antacid combinations. Clinically meaningful damage occurred in all subjects receiving plain aspirin, 93% of those receiving aspirin-antacid combination and only 27% and 20% of those receiving enteric-coated aspirin granules qid and bid, respectively. All three aspirin formulations were taken as 1 g qid (4 g/day) and an additional group received enteric granules administered as 2 g bid (4 g/day). Gastric damage was assessed by means of endoscopy carried out after seven days of treatment. Enteric granules are equally safe when administered on a bid or qid regimen (at same total daily dosage) and, in a bid regimen, should provide a compliance advantage for patients on high-dose therapy for diseases such as rheumatoid arthritis.

Final report on the cost of treating arthritic disease: comparison between salicylates and nonsalicylate nonsteroidal anti-inflammatory drugs

The cost of antacids or other drugs and hospital admission for the treatment of gastrointestinal side effects must be factored into any comparison between costs of nonsteroidal anti-inflammatory drugs and salicylate drugs in the treatment of arthritis. Records and interviews of 534 patients treated for arthritis, 310 treated with nonsalicylate nonsteroidal anti-inflammatory drugs and 224 treated with salicylates, were evaluated for this comparison. Costs of the basic drug, medical treatment for gastrointestinal side effects, and hospitalization for such treatment were added, averaged for 30-day per patient treatment periods, and compared. When hospital costs were excluded, costs per patient per month of nonsteroidal anti-inflammatory drug therapy were comparable to costs of nonacetylated salicylate therapy, and both sums were more than twice the cost of therapy with an aspirin compound. When hospital costs were included, average non-acetylated salicylate costs per patient per month were far higher than those for treatment with either aspirin or nonsteroidal anti-inflammatory drugs. These findings suggest the value of randomized multicenter studies to establish the cost-effectiveness nonsteroidal anti-inflammatory drug therapy v salicylate therapy in the treatment of arthritis.

Aspirin and gastrointestinal haemorrhage: a methodologic assessment

The literature on the association between Aspirin (ASA) use and gastrointestinal haemorrhage (GIH) has been reviewed. Thirteen control-studies were selected and examined for (i) the type of design (ii) the choice of outcome measures, and (iii) the adequacy of satisfying defined causation criteria and the influence of sampling strategies on one of these criteria--strength of association. Of the 13 studies seven were large scale randomized control trials (RCTs) and six were case-control studies. Among the outcome measures utilized in these studies and currently available for the assessment of GIH, we found none were uniquely satisfactory for use as a "gold standard". Furthermore, in none of these studies was the particular chosen outcome measure sufficiently satisfactory to allow firm conclusions on the issue of causation. None of the studies adequately met all the defined causation criteria or adequately eliminated the potential biases in the chosen sampling strategies. Thus the evidence that aspirin causes GIH fails to stand up to critical evaluation. This, of course, does not mean that ASA does not cause GIH. However, it is common practice for physicians to advise their patients with a prior history of GIH and or gastrointestinal symptoms to refrain from ASA use. This is probably sound advice in the setting where ASA is being used as a casual or short term analgesic or anti-inflammatory agent. But in the context of severe inflammatory joint disease when the use of ASA is clinically indicated, it should not be withheld on the basis of the risk of GIH. There is a widespread belief in medicine that by implication aspirin and other nonsteroidal anti inflammatory drugs are a common cause of bleeding from the gastrointestinal tract, yet it has been pointed out frequently [1-3] that the evidence to support the belief is weak and circumstantial. Despite this the perceived association of aspirin with gastrointestinal bleeding influences both pharmaceutical and clinical practice and often hinders or prevents the prescription of anti-inflammatory medication to patients with severe inflammatory joint disease. It was felt that a proper critical appraisal of the evidence was essential. It is unfortunate that the evidence most frequently cited implicating ASA as a cause of GIH is almost entirely related to the casual use of the drug. Thus our conclusions must be viewed with some caution in the patient group where this knowledge would be of most importance, that is in patients with inflammatory joint disease.