Nonsteroidal antiinflammatory drugs and lower gastrointestinal bleeding

The Association of Drugs With Severity and Specific Causes of Acute Lower Gastrointestinal Bleeding: A Prospective Study

OBJECTIVES

Studies on the association of acute lower gastrointestinal bleeding (ALGIB) and drugs are scarce. We aimed to investigate the association of drugs and ALGIB, especially regarding specific causes of ALGIB, and their role in the severity of ALGIB.

MATERIALS AND METHODS

The study was prospective and included all patients undergoing colonoscopy in 2010 and 2013 at the National University Hospital of Iceland. Use of nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin (LDA), and warfarin before ALGIB was registered. Clinically significant bleeding was defined as: hemoglobin <100 g/L, hemodynamic instability, blood transfusion, surgery, or death.

RESULTS

Overall, 2392 patients underwent 2751 colonoscopies, of those, 325 (14%) had ALGIB, mean age 64 years (±20). The commonest diagnoses were diverticulosis (22%) and ischemic colitis (14%). In multivariate analysis, NSAIDs, LDA, and warfarin use was associated with ALGIB, odds ratio (OR) 3.3 [95% confidence interval (95% CI), 1.99-5.82], OR 1.5 (95% CI, 1.01-2.13), and OR 2.7 (95% CI, 1.61-4.57), respectively. Clinically significant bleeders were more likely than nonclinically significant bleeders to use NSAIDs or LDA+warfarin, OR 2.3 (95% CI, 1.26-3.76) and OR 33.0 (95% CI, 6.74-595), respectively. Patients with diverticular bleeding had greater odds than controls of NSAID, LDA, and warfarin use, OR 8.3 (95% CI, 3.8-18.3), OR 2.1 (95% CI, 1.15-3.67), and OR 2.6 (95% CI, 1.24-5.56), respectively. Patients with ischemic colitis were more likely than controls to use LDA, OR 2.3 (95% CI, 1.14-4.45).

CONCLUSIONS

NSAIDs, LDA, and warfarin were associated with ALGIB and diverticular bleeding. These drugs may have a role in other etiologies of ALGIB and seem to increase the risk of clinically significant bleeding.

Effect of proton-pump inhibitors on the risk of lower gastrointestinal bleeding associated with NSAIDs, aspirin, clopidogrel, and warfarin

BACKGROUND

We investigated the effects of proton-pump inhibitors (PPIs) on lower gastrointestinal bleeding (LGIB) and of their interactions with nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, clopidogrel, and warfarin on LGIB risk.

METHODS

We prospectively studied 355 patients emergently hospitalized for LGIB and 8,221 nonbleeding patients. All patients underwent colonoscopy. Smoking, alcohol drinking, drug exposure, and the Charlson comorbidity index score were assessed before colonoscopy. Adjusted odds ratios (AOR) of LGIB were estimated.

RESULTS

LGIB was significantly associated with older age, higher comorbidity index, and NSAID, aspirin, clopidogrel, or warfarin use. PPI use was significantly associated with older age, male sex, being a current alcohol drinker, higher comorbidity index, and NSAID, aspirin, clopidogrel, warfarin, acetaminophen, or corticosteroid use. Multivariate analysis adjusted by the confounding factors revealed LGIB was not significantly associated with PPI use (AOR 0.87; 95 % confidence interval 0.68-1.13; p = 0.311), or specifically with omeprazole (AOR 1.18; p = 0.408), esomeprazole (AOR 0.76; p = 0.432), lansoprazole (AOR 0.93; p = 0.669), or rabeprazole (AOR 0.63; p = 0.140). In the interaction model, no significant interactions were observed between PPIs and NSAIDs (AOR 1.40; p = 0.293), aspirin (AOR 1.09; p = 0.767), clopidogrel (AOR 0.99, p = 0.985), or warfarin (AOR 1.52; p = 0.398).

CONCLUSIONS

This large case-control study demonstrated that PPI use did not lead to an increased risk of LGIB, regardless of the type of PPI used. Further, LGIB risk was not affected by PPI use, irrespective of concomitant therapy with NSAIDs, low-dose aspirin, clopidogrel, or warfarin.

Lower GI bleeding risk of nonsteroidal anti-inflammatory drugs and antiplatelet drug use alone and the effect of combined therapy

BACKGROUND

The effect of a combined antithrombotic drug regimen on lower GI bleeding (LGIB) remains unknown.

OBJECTIVE

To investigate the risk of LGIB associated with nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, thienopyridine (ticlopidine or clopidogrel), or other antiplatelets used.

DESIGN

Prospective study.

SETTING

Emergency hospital, gastroenterology department.

PATIENTS

A cohort of 319 patients emergently hospitalized for acute, continuous, or frequent LGIB and 3358 patients with no bleeding on colonoscopy.

MAIN OUTCOME MEASUREMENTS

Odds ratios (ORs) for the risk of LGIB associated with drug exposure adjusting for age, sex, smoking, alcohol, medications, comorbidities, and GI symptom scores.

RESULTS

After considering antithrombotic drugs by dividing them into single- and combined-use, single use of nonselective NSAID or cyclooxygenase-2 inhibitor was independently associated with LGIB. The combined use of NSAIDs with low-dose aspirin (OR 4.3) or with other antiplatelets (OR 4.9) was more associated with LGIB than the use of NSAIDs alone (OR 2.3). Use of low-dose aspirin, thienopyridine, or other antiplatelets alone was not significantly associated with LGIB, but combined use of low-dose aspirin with thienopyridine (OR 2.2) or with other antiplatelets (OR 3.6) was associated with LGIB. Combined use of different NSAIDs carried a higher risk than single use (combined use, OR 4.9; single use, OR 2.3).

LIMITATIONS

Single-center study.

CONCLUSION

The use of nonselective or selective NSAIDs alone was associated with LGIB. Although antiplatelet use alone was not significantly associated with LGIB, combined use of NSAIDs with antiplatelets or of low-dose aspirin with thienopyridine or with nonthienopyridine antiplatelets was independently associated with LGIB.

Lower gastrointestinal bleeding: incidence, etiology, and outcomes in a population-based setting

OBJECTIVES

To investigate the incidence and outcomes of acute lower gastrointestinal bleeding (ALGIB) in a population-based setting and examine the role of drugs potentially associated with GIB.

METHODS

The study was prospective and population based. The cohort included all patients who underwent colonoscopy during the year 2010 at the National University Hospital of Iceland. Indications for endoscopies and drug history were recorded in a systematic manner. The inclusion criteria were overt bleeding leading to hospitalization or occurring in hospitalized patients. The use of NSAIDs, low-dose aspirin, warfarin, selective serotonin receptor inhibitors, and bisphosphonates before GIB was also checked in a Pharmaceutical Database covering all drug prescriptions in the country. A control group included patients who underwent colonoscopy during the study period and did not have GIB.

RESULTS

Altogether, 1134 patients underwent 1275 colonoscopies. Overall, 163 patients had ALGIB. The crude incidence for ALGIB was 87/100 000 inhabitants/year. The most common findings were diverticulosis (23%) and ischemic colitis (16%). A total of 7.4% of individuals had endoscopic therapy and none had undergone surgery. Two (1.2%) patients died because of ALGIB, both with severe comorbidities. Overall, 19% with ALGIB were on NSAIDs versus 9% in nonbleeders (P=0.0096); 37% with ALGIB were on low-dose aspirin versus 25% in nonbleeders (P=0.0222).

CONCLUSION

The incidence for ALGIB is the highest reported to date. The most common reasons for ALGIB were diverticulosis and ischemic colitis. Mortality during hospitalization was very low. NSAIDs and low-dose aspirin seem to increase the risk for ALGIB.

A novel composite endpoint to evaluate the gastrointestinal (GI) effects of nonsteroidal antiinflammatory drugs through the entire GI tract

OBJECTIVE

Nonsteroidal antiinflammatory drugs (NSAID) not only cause damage to the upper gastrointestinal (GI) tract but also affect the lower GI tract. To date, there is no endpoint that evaluates serious GI events in the entire GI tract. The objective of this report is to introduce a novel composite endpoint that measures damage to the entire GI tract - clinically significant upper and lower GI events (CSULGIE) - in patients with NSAID-induced GI damage.

METHODS

We reviewed the data from largescale, multicenter, randomized, clinical trials on lower GI toxicity associated with NSAID use. The rationale for using CSULGIE as a primary endpoint in 2 ongoing trials - the Celecoxib vs Omeprazole and Diclofenac for At-risk Osteoarthritis (OA) and Rheumatoid Arthritis (RA) Patients (CONDOR) trial and the Gastrointestinal Randomized Events and Safety Open-Label NSAID Study (GI-REASONS) - is also discussed.

RESULTS

Previous randomized trials focused primarily on damage to the upper GI tract and often neglected the lower GI tract. The CSULGIE endpoint extends the traditional "perforation, obstruction, and bleeding" assessment of upper GI complications by including events in the lower GI tract (small/large bowel) such as perforation, bleeding, and clinically significant anemia.

CONCLUSION

By providing clinicians with a new, descriptive language for adverse events through the entire GI tract, the CSULGIE endpoint has the potential to become a standard tool for evaluating the GI effects of a range of therapies.

Adverse effects of nonsteroidal anti-inflammatory drugs on the colon

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used, and a growing body of evidence suggests that they have adverse effects in the lower gastrointestinal (GI) tract in addition to the well-described toxicity in the upper GI tract. Among NSAID users who develop adverse GI effects, the proportion with lower GI events is as high as 40%. Most of the available evidence is taken from case-control studies and case reports; no large, randomized, placebo-controlled study has specifically set out to determine the magnitude of NSAID toxicity on the colon. However, the data suggest that NSAIDs cause a primary macroscopic colitis, collagenous colitis, an increased risk of complicated diverticular disease, and exacerbations of preexisting inflammatory bowel disease. Treatment depends on withdrawal of the causative drug.

Hospitalizations for upper and lower GI events associated with traditional NSAIDs and acetaminophen among the elderly in Quebec, Canada

BACKGROUND

The risk of upper/lower gastrointestinal (GI) adverse events associated with the concomitant use of traditional nonsteroidal anti-inflammatory drugs (tNSAIDs) with acetaminophen has not been assessed. Among users of these drugs, the concomitant use of proton pump inhibitors (PPIs) with tNSAIDs may reduce the risk of upper GI adverse events, but its effect on lower GI events is not clear.

OBJECTIVE

To compare the rates of GI hospitalization (ulceration, perforation, or bleeding in the upper or lower GI tract) among elderly patients taking tNSAIDs or the combination of a tNSAID and acetaminophen with and without a PPI versus those taking acetaminophen alone.

METHODS

We conducted a population-based retrospective cohort study using data obtained from the government of Quebec health insurance agency databases and the hospital discharge summary database. Patients of 65 yr of age or older who filled a prescription for acetaminophen or a tNSAID between January 1998 and December 2004 were entered in the cohort at the date of the first filled prescription from either of these medications (index date). Follow-up ended at the first date of a GI hospitalization, death, or the end of the study period.

RESULTS

The cohort included 644,183 elderly patients. These patients received 1,778,541 prescriptions for tNSAIDs (315,222, 17.7% with a PPI), 158,711 for the combination of a tNSAID and acetaminophen (40,797, 25.7% with a PPI), 1,597,725 for acetaminophen (> 3 g/day) (504,939, 31.6% with a PPI), and 3,641,140 for acetaminophen (< or = 3 g/day) (1,031,939, 28.3% with a PPI). Using Cox regression models that adjusted for time-dependent variables (aspirin, anticoagulants, and clopidogrel) and other fixed patient baseline characteristics, we found similar risks of GI hospitalizations among time periods when patients were exposed to either a tNSAID with a PPI, acetaminophen (> 3 g/day) with a PPI, or acetaminophen (< or = 3 g/day) with a PPI. The risk of GI hospitalization among users of PPIs during exposure to the combination of acetaminophen with a tNSAID was twice as high as that of the reference category, acetaminophen (< or = 3 g/day) without a PPI (hazard ratio [HR] 2.15, 95% confidence interval [CI][1.35-3.40]). Among nonusers of PPIs, the risk of GI hospitalization was 1.20 (1.03-1.40) during exposure to acetaminophen (> 3 g/day), 1.63 (1.44-1.85) during exposure to tNSAIDs, and 2.55 (1.98-3.28) during exposure to the combination of a tNSAID and acetaminophen compared with the reference category.

CONCLUSION

Among elderly patients requiring analgesic/anti-inflammatory treatment, use of the combination of a tNSAID and acetaminophen may increase the risk of GI bleeding compared with either agent alone.

Faecal blood loss with aspirin, nonsteroidal anti-inflammatory drugs and cyclo-oxygenase-2 selective inhibitors: systematic review of randomized trials using autologous chromium-labelled erythrocytes

Introduction

Faecal blood loss has been measured using autologous erythrocytes labelled with radioactive chromium for several decades, using generally similar methods. We conducted a systematic review of studies employing this technology to determine the degree of blood loss associated with use of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclo-oxygenase-2 selective inhibitors (coxibs).

Methods

A systematic search of PubMed and the Cochrane Library (to December 2006) was conducted to identify randomized trials in which treatment with aspirin, NSAIDs, or coxibs was continued for at least 7 days, and with at least 7 days of washout for crossover trials. Rates of faecal blood loss associated with these agents were determined in the randomized trials identified. Comparators were placebo, active, or no treatment. Outcomes of interest were mean daily faecal blood loss, and the number or proportion of individuals recording faecal blood above 5 ml/day and above 10 ml/day.

Results

Forty-five reports of 47 trials were included, including 1,162 individuals, mostly healthy volunteers and predominantly young men. Only 136 patients (as opposed to healthy volunteers; 12%) were included, and these were mostly older people with an arthritic condition. Most NSAIDs and low-dose (325 mg) aspirin resulted in a small average increase in faecal blood loss of 1 to 2 ml/day from about 0.5 ml/day at baseline. Aspirin at full anti-inflammatory doses resulted in much higher average levels of blood loss of about 5 ml/day. Some individuals lost much more blood than average, at least for some of the time, with 5% of those taking NSAIDs having daily blood loss of 5 ml or more and 1% having daily blood loss of 10 ml or more; rates of daily blood loss of 5 ml/day or 10 ml/day were 31% and 10%, respectively, for aspirin at daily doses of 1,800 mg or greater.

Conclusion

At baseline, or with placebo, faecal blood loss is measured at 1 ml/day or below. With low-dose aspirin and some NSAIDs, average values may be two to four times this, and anti-inflammatory doses of aspirin result in much higher average losses. A small proportion of individuals respond to aspirin or NSAIDs with much higher faecal blood loss of above 5 ml/day or 10 ml/day. There are significant limitations regarding the quality and validity of reporting of these studies, such as limited size and inclusion of inappropriate participants. The potential for blood loss and consequent anaemia requires more study.

Systematic review: the lower gastrointestinal adverse effects of non-steroidal anti-inflammatory drugs

BACKGROUND

Lower gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs) are much more poorly characterized than upper gastrointestinal effects.

AIM

To determine if NSAIDs increase lower gastrointestinal adverse effects and if the risk with non-selective NSAIDs is greater than with cyclooxygenase-2-selective inhibitors (coxibs).

METHODS

Computerized databases were searched to identify studies of NSAID use reporting on lower gastrointestinal integrity (e.g. permeability), visualization (e.g. erosions, ulcers) and clinical events.

RESULTS

Designs in 47 studies were randomized (18), case-control (14), cohort (eight) and before-after (seven). Non-selective-NSAIDs had significantly more adverse effects vs. no NSAIDs in 20 of 22 lower gastrointestinal integrity studies, five of seven visualization studies, seven of 11 bleeding studies (OR: 1.9-18.4 in case-control studies), two of two perforation studies (OR: 2.5-8.1) and five of seven diverticular disease studies (OR: 1.5-11.2). Coxibs had significantly less effect vs. non-selective-NSAIDs in three of four integrity studies, one endoscopic study (RR mucosal breaks: 0.3), and two randomized studies (RR lower gastrointestinal clinical events: 0.5; haematochezia: 0.4).

CONCLUSIONS

An increase in lower gastrointestinal injury and clinical events with non-selective-NSAIDs appears relatively consistent across the heterogeneous collection of trials. Coxibs are associated with lower rates of lower gastrointestinal injury than non-selective-NSAIDs. More high-quality trials are warranted to more precisely estimate the effects of non-selective-NSAIDs and coxibs on the lower gastrointestinal tract.

GI Risk and Risk Factors of NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used drugs in the United States. Ulcers are found at endoscopy in 15% to 30% of patients using NSAIDs regularly. The annual incidence of upper gastrointestinal (GI) complications such as bleeding with regular NSAID use is approximately 1.0% to 1.5%, whereas the annual rate of upper GI clinical events (complicated plus symptomatic uncomplicated ulcers) is approximately 2.5% to 4.5%. Upper GI symptoms such as dyspepsia also occur in many patients taking NSAIDs--at a relative risk of about 1.5 to 2 compared with that in patients without NSAID use. Important risk factors for upper GI clinical events include older age, prior history of upper GI events, use of corticosteroids or anticoagulants, and high-dose or multiple NSAIDs (including NSAID plus low-dose aspirin). Lower GI clinical events such as bleeding may also occur with NSAIDs, although they are less common and less well studied than upper GI events. The decision to employ a protective strategy to decrease NSAID-associated GI clinical events is based on risk stratification. Strategies employed include the use of non-NSAID analgesics, use of lowest effective dose of NSAID, use of medical cotherapy (eg, proton pump inhibitor, misoprostol), or use of coxibs.

Strictures, diaphragms, erosions or ulcerations of ischemic type in the colon should always prompt consideration of nonsteroidal anti-inflammatory drug-induced lesions

AIM: To investigate whether NSAIDs/ASA lesions in the colon can histologically be diagnosed on the basis of ischemic necrosis similar to biopsy-based diagnosis of NSAIDs/ASA-induced erosions and ulcers of the stomach.

METHODS: In the period between 1997 and 2002, we investigated biopsy materials obtained from 611 patients (415 women, 196 men, average age 60.5 years) with endoscopic focal erosions, ulcerations, strictures or diaphr-agms in the colon. In the biopsies obtained from these lesions, we always established the suspected diagnosis of NSAID-induced lesions whenever necroses of the ischemic type were found. Together with the histological report, we enclosed a questionnaire to investigate the use of medication. The data provided by the questionnaire were then correlated with the endoscopic findings, the location, number and nature of the lesions, and the histological findings.

RESULTS: At the time of their colonoscopy, 86.1% of the patients had indeed been taking NSAID/ASA medication for years (43.9%) or months (29.5%). The most common indication for the use of these drugs was pain (64.3%), and the most common indication for colonoscopy was bleeding (55.5%). Endoscopic inspection revealed multiple erosions and/or ulcers in 60.6%, strictures in 15.8%, and diaphragms in 3.0% of the patients. The lesions were located mainly in the right colon including the transverse colon (79.9%). A separate analysis of age and sex distribution, endoscopic and histological findings for NSAIDs alone, ASA alone, combined NSAID/ASA, and for patients denying the use of such drugs, revealed no significant differences among the groups.

CONCLUSION: This uncontrolled retrospective study based on the histological finding of an ischemic necrosis shows that the histologically suspected diagnosis of NSAID-induced lesions in the colon is often correct. The true diagnostic validity of this finding and the differentiation from ischemic colitis should, however, be investigated in a prospective controlled study.

Rebleeding and survival after acute lower gastrointestinal bleeding

BACKGROUND

Previous studies of acute lower gastrointestinal bleeding (LGIB) have focused on evaluation and therapy. Measurement of long-term outcome has been rare. The purpose of this study was to document rebleeding and survival rates in patients with acute LGIB.

METHODS

A retrospective review of all patients undergoing technetium-labeled red blood cell scans for LGIB from January of 1997 to December of 2002 was performed. Rebleeding was defined as identification of enteric bleeding requiring a transfusion 2 or more weeks after the initial bleeding episode.

RESULTS

A total of 119 patients met inclusion criteria. Rebleeding was documented in 14 of 102 patients surviving for more than 2 weeks. The actuarial rebleeding rate was 15% at 2 years. No factors were identified that portended a higher likelihood of rebleeding. The 30-day mortality was 18% and the median survival was 60 months for the entire cohort. Of the 36 patients in whom cause of death was documented, 4 died of surgical complications and a single patient died as a direct result of hemorrhage.

CONCLUSIONS

Rebleeding after an initial episode of LGIB occurs in a small percentage of individuals. Although survival is poor for patients with LGIB, few patients die as a direct consequence of hemorrhage.

Colon perforation with acute peritonitis after taking clindamycin and diclofenac following wisdom tooth removal

INTRODUCTION

Non-steroidal anti-inflammatory drugs have a high analgesic and anti-inflammatory effect and are widely taken for acute and chronic pain. Especially following long-term use, they may cause gastrointestinal side effects such as mucosal ulceration, perforation and strictures in the small and large bowel.

PATIENT

A 16-year-old female developed colonic perforation and purulent peritonitis after wisdom tooth removal and short-term intake of non-steroidal anti-inflammatory drugs.

DISCUSSION

Non-steroidal anti-inflammatory drugs may exert their deleterious effects on the lower gastrointestinal tract through both local and systemic actions. Systemic effects are caused by the inhibition of cyclooxygenase and reduction of protective prostaglandins. The local damage of the intestinal mucosa in the distal bowel segments seems to be caused by sustained release formulation with a high enterohepatic circulation. The latter may act time and again on the intestinal mucosa through metabolites secreted in the gallbladder. Concomitant intake of clindamycin may have favoured this acute complication.

CONCLUSION

Intestinal perforation after short-term intake of non-steroidal anti-inflammatory drugs is very rare. However, it is life-threatening and illustrates the need for careful prescribing at as low an effective dose and as short a time as possible, especially when combining different drugs. Paracetamol only has a weak effect on cyclooxygenase and continues to be a possible alternative for postoperative dental pain with a favourable benefit-risk ratio. It is the drug of choice for children, adolescents and patients with an increased risk of non-steroidal anti-inflammatory drug-induced gastro-enteropathy.

Benefit-risk assessment of rofecoxib in the treatment of osteoarthritis

NSAIDs are widely used to treat pain and inflammation in osteoarthritis. Their use in this indication is generally intermittent and fluctuates with the intensity of the disease. Nonetheless, success of the therapy is frequently limited by injury to the gastrointestinal mucosa and complications such as bleeding, ulceration and perforation. A careful and detailed evaluation of these aspects in regard to the newly introduced NSAIDs is of considerable clinical importance. This review focuses on the NSAID rofecoxib, one of the selective cyclo-oxygenase (COX)-2 inhibitors, which are claimed to be as effective as nonselective NSAIDs with better gastrointestinal tolerability. Indeed, phase II, phase III and epidemiological studies have revealed that the efficacy of rofecoxib is comparable to that of conventional NSAIDs but with lower gastrointestinal toxicity, although this advantage may not be demonstrable in every patient. In patients treated with low-dose aspirin (acetylsalicylic acid) for cardiovascular prophylaxis, celecoxib (another selective COX-2 inhibitor) seems to have no obvious advantages over conventional NSAIDs, and similar conclusions may be applied to rofecoxib. A comparison of NSAID therapy +/- concomitant low-dose aspirin was not a primary outcome in this trial with celecoxib and there is thus a need for further studies which compare the gastrointestinal risk of a selective COX-2 inhibitor plus aspirin versus a conventional NSAID. Recent debate has emerged regarding the cardiovascular safety of rofecoxib. Although there is evidence both for and against higher cardiovascular risk with rofecoxib, a retrospective cohort study recently published suggested that there is no increased risk of acute myocardial infarction in the short-term when compared with non-selective NSAIDs. The renal toxicity of rofecoxib has been thoroughly investigated. Clinical studies revealed renal effects of rofecoxib similar to those of conventional NSAIDs. Since adverse effects increase with the degree of renal impairment, monitoring of renal function should be carried out in patients at risk. Although there are still insufficient data concerning certain important adverse effects of rofecoxib, this drug is becoming an important alternative in the therapy of osteoarthritis, especially in high-risk patients. Clinicians need to weigh up the benefits and risks of rofecoxib on a case-by-base basis.

Nitric oxide releasing drugs: from bench to bedside

NO biology has had an enormous boost and several aspects of its role in physiology and pathology has been extensively studied. NO acts as a double edge sword mediator that has beneficial physiological effects as well as detrimental pathological effects making very difficult to develop drugs. Studies on nitric oxide therapeutic approach can be divided into two simple approaches: one directed to increase the NO release and another to inhibit NO release. Gene therapy approach have been also developed and pre-clinical data on iNOS and eNOS have shown promising results in post-angioplasty restenosis. The major limitation to the use of NSAID is represented by their ability to cause ulceration and bleeding in the gastrointestinal tract NO plays an important role in GI integrity. NO releasing NSAID have higher GI tolerability and retain their anti-inflammatory activity as well as the ability to inhibit platelet aggregation. NO-NSAIDs not only represents a new class of drugs but they represent the first "proof of concept" on the key role of NO in the gastrointestinal homeostasis.

Clinical implications of prostaglandin inhibition in the small bowel

NSAID-induced intestinal toxicity is more common than previously recognized and may have clinically significant sequelae, especially in elderly arthritic patients. Increased awareness of the potential intestinal complications associated with prostaglandin inhibition is required for early recognition and appropriate management. An increase in the level of suspicion by physicians may lead to earlier diagnosis and subsequent discontinuation of the offending NSAID; this is important in that discontinuation of the offending agent may be preferable to multiple endoscopic radiologic and surgical procedures in the patient with obscure blood loss and anemia. Appropriate diagnosis in selected patients may prevent the increased morbidity and mortality associated with small intestinal surgery. The emergence of selective COX-2 inhibitors likely will bring this issue to the forefront because it will become increasingly important to determine the effects of these agents on the small intestine and colon, in addition to their effects on the gastroduodenal mucosa. The new generation of selective COX-2 inhibitors may offer a potential therapeutic advantage over the nonselective NSAIDs with respect to their intestinal toxicity. Well-designed safety trials that have intestinal injury as a predefined end point will provide important information as to the overall gastrointestinal safety of these compounds. These agents must be evaluated with respect to their overall safety profile and not just by their gastrointestinal safety. Nevertheless, these agents are continuing to provide new directions for exciting basic and clinical scientific investigation.

Acute gastrointestinal bleeding

Acute gastrointestinal bleeding is a significant worldwide medical problem. Despite modern measures for diagnosis and treatment, morbidity and mortality rates associated with gastrointestinal bleeding remain largely unchanged. Aggressive medical resuscitation while initiating an evaluation to localize the site of blood loss remains the key to successful management of acute gastrointestinal bleeding. A multidisciplinary approach with early involvement of a gastroenterologist, surgeon, and radiologist can be extremely helpful in the management of these patients. With the logical and direct approach to the evaluation of patients with gastrointestinal bleeding described in this article, most episodes can be managed successfully.

Clinical, endoscopic, and histologic spectrum of nonsteroidal anti-inflammatory drug-induced lesions in the colon

PURPOSE

It has become increasingly clear that nonsteroidal anti-inflammatory drugs may cause damage not only to the upper gastrointestinal tract but also to the small and large intestine. Although the colon may be readily investigated by endoscopy, drug-induced lesions are not well known, probably because they are considered to occur only rarely. In the present study we describe endoscopic, histologic, and gross characteristics of nonsteroidal anti-inflammatory drug-induced colonic damage. Furthermore, pathogenetic mechanisms and therapeutic options are discussed.

METHODS

The histories of all patients diagnosed as having nonsteroidal anti-inflammatory drug colitis during the last two years at the department of gastroenterology or the department of pathology at our hospital were reviewed. Endoscopic, histologic, and gross pathologic findings were systematically recorded. In addition, data on duration and type of nonsteroidal anti-inflammatory drug intake and time from onset of symptoms to diagnosis were collected. Therapy and outcome of our patients, if available, are reported.

RESULTS

During the study period 11 patients were diagnosed as having nonsteroidal anti-inflammatory drug colitis. Most patients presented with diarrhea with or without blood loss and complained about diffuse abdominal pain. Endoscopy revealed flat ulcers in the entire colon being more severe in the right colon in the three cases with acute onset of diarrhea. In four cases concentric "diaphragm-like" strictures were seen, all located in the right colon. In the remainder endoscopy showed nonspecific erosions and was normal in one patient. Histology revealed findings similar to ischemic colitis. Additionally, in two cases collagenous colitis was found. Diclofenac slow release was the most commonly involved drug. The median time from onset of symptoms to diagnosis was 1.8 (range, 0-11.5) years.

CONCLUSIONS

Nonsteroidal anti-inflammatory drug colitis is a clinically significant disease, which may present with diarrhea, anemia, and nonspecific abdominal complaints. Careful history taking, together with awareness of endoscopic and histologic findings, allows a timely diagnosis of this disease.

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.

Selected drug complications and treatment conflicts in the presence of coexistent diseases

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

Nonsteroidal anti-inflammatory drug-associated toxicity of the liver, lower gastrointestinal tract, and esophagus

Although upper gastrointestinal (GI) adverse events are the most common consequences of nonsteroidal anti-inflammatory drug (NSAID) use, there are other GI side effects that can contribute to the morbidity and mortality associated with these drugs. NSAID-associated toxicity of the large and small bowel is increasingly recognized in clinical practice, as enteroscopic procedures become more frequently used. This lower GI toxicity may have several different manifestations: ulcerations, strictures, colitis, or exacerbation of inflammatory bowel disease. Hepatic injury, most likely due to an idiosyncratic reaction resulting from an immunologic response or altered metabolic pathways, is another sequela of NSAID use that is usually reversible. Although hepatotoxicity is listed as a class warning for NSAIDs, aspirin, diclofenac, and sulindac are most commonly associated with this problem. Surveillance for hepatic injury is not always reliable, and the low frequency of both hepatic and lower GI toxicity in NSAID users renders these events difficult to characterize. An increase in awareness, surveillance, and reporting of these events can lead to a better understanding of the risk factors and etiology associated with NSAID toxicity.

Bowel inflammation and the spondyloarthropathies

The concept of spondyloarthropathies gathers together a group of chronic diseases in which not only the locomotor system is involved but also other organs, especially the gastrointestinal tract. In humans, ileocolonoscopic studies demonstrated the presence of inflammatory gut lesions in all the diseases in the spondyloarthropathy group; their presence varied in the different diseases between 20% and 70%. The inflammation could be related to specific disease features in the spondyloarthropathies. Further research supports the hypothesis of subclinical inflammatory bowel disease in some patients with spondyloarthropathy, in which the locomotor inflammation was the only clinical manifestation. The link between gut inflammation and arthropathy has also been demonstrated in animal models, notably the human leukocyte antigen B27 transgenic rats. The temporal relationship between activity and severity of colonic involvement and flares of peripheral arthritis directs treatment of choice. For all forms of enterogenic arthropathies, nonsteroidal anti-inflammatory drugs remain the acute treatment form. Caution is in order, however, because of their possible harmful effects on intestinal integrity, permeability, and even on gut inflammation.

[Risk of ulcer and its prophylaxis in therapy with non-steroidal antirheumatic drugs]

Nonsteroidal antiinflammatory drugs (NSAIDs) are among the most frequently prescribed drugs in western countries. The high incidence of adverse gastrointestinal effects which are potentially life-threatening require steps for prevention. The use of NSAIDs should be restricted to patients with inflammatory rheumatic diseases. If NSAIDs are indicated it is important to identify patients who are at high risk to develop serious gastrointestinal side effects. These patients should receive Misoprostol at a dose of 2 to 3 x 200 micrograms per day. Up to date Misoprostol is the only drug with proven efficacy with respect to the prevention of gastroduodenal ulcer and its complications. NSAIDs inhibit the key enzyme of prostaglandin synthesis, the cyclooxygenase. Recently published data show that 2 isoenzymes of the cyclooxygenase exists. Cyclooxygenase-1 is primarily involved in the maintenance of organ function whereas cyclooxygenase-2 is expressed in inflamed tissue. Specific cyclooxygease-2 inhibitors have been developed. Clinical trials have to prove if the concept of a selective cyclooxygenase-2 inhibition with high antiinflammatory potency but lack of gastrointestinal side effects holds true in humans.

The conundrum of lower gastrointestinal bleeding

Acute massive hematochezia provides one of the greatest diagnostic and therapeutic challenges to the physician. Although most patients stop bleeding spontaneously and further evaluation can be carried on with less urgency, 10% to 15% require urgent diagnostic and therapeutic procedures. Clearly, the least invasive effective solution to the bleeding problem is generally the best, although in some cases, emergency undirected surgery may be necessary. Subtotal colectomy can be done with acceptable morbidity and mortality in this situation, provided that the surgeon is confident of a colonic source of the bleeding. An understanding of the strategies outlined above encourages the management of such patients with an eye to maximizing therapeutic benefit while minimizing morbidity.

Gastrointestinal endoscopy in patients taking antiplatelet agents and anticoagulants: survey of ASGE members. American Society for Gastrointestinal Endoscopy

BACKGROUND

Gastrointestinal endoscopy is often required in patients taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or anticoagulants. Because proper guidelines are lacking, we believe that most endoscopists use their own criteria and judgment for stopping and restarting these agents during the periendoscopic period, and the practice varies widely. The aim of our study was to identify these practices among ASGE members.

METHODS

Questionnaires, each containing 22 questions with 157 responses, were sent to 3300 ASGE members, including all Gastroenterology Fellowship Program Directors. One thousand two hundred sixty-nine questionnaires were received and analyzed.

RESULTS

Physicians stopped aspirin and NSAIDs more frequently before colonoscopy (81%) and ERCP (79%) than before upper endoscopy (51%) (p < 0.001). Ninety percent of physicians stopped aspirin and NSAIDs for 10 or fewer days. Only 20% of physicians performed sphincterotomy when aspirin and NSAIDs were not stopped compared with 88% and 85% (p < 0.001 for both) of physicians performing cold biopsies at esophagogastroduodenoscopy and colonoscopy, respectively, and 77% and 69% performing hot biopsies for the same procedures (p < 0.001 for all compared with sphincterotomy). Depending on the indication for anticoagulation, 51% to 60% of physicians stopped warfarin before upper endoscopy; 71% to 82% before colonoscopy; and 26% to 51% of physicians used a "heparin window." All physicians restarted warfarin immediately after diagnostic endoscopy, whereas 80% restarted it 7 or fewer days after therapeutic endoscopy.

CONCLUSIONS

We conclude that a wide variation exists regarding the management of aspirin, NSAIDs, and anticoagulants in the periendoscopic period. There is a definite need for a consensus statement or guidelines for managing patients taking these agents.

NSAIDs, gastrointestinal injury, and cytoprotection

Gastrointestinal toxicity caused by nonsteroidal anti-inflammatory drugs (NSAIDs) is the most frequent drug side effect in the United States. NSAIDs are implicated in the development of complicated peptic ulcer disease and injury to the small bowel and colon. NSAIDs interfere with prostaglandin-mediated epithelial defense mechanisms and also cause direct epithelial toxicity. Current and future approaches to the prevention and management of NSAID injury are reviewed.

Non-steroidal anti-inflammatory drugs and variceal bleeding: a case-control study

BACKGROUND/AIM

The aim of this case-control study was to assess the risk of bleeding from esophageal varices associated with aspirin and non-steroidal anti-inflammatory drug consumption.

METHODS

Between January 1992 and May 1994, patients admitted for bleeding from esophageal or gastric lesions related to portal hypertension were matched with a control patient of the same age and sex, who was free of gastrointestinal bleeding. A structured interview was conducted with the cases and controls to determine drug consumption during the 2 weeks preceding admission. Fifty-nine cases and 59 controls were recruited.

RESULTS/CONCLUSIONS

Use of aspirin was more prevalent among the cases than the controls (odds ratio 3.81; 95% confidence interval 1.36-11.64; p = 0.004). This difference remained significant in the subgroups of patients with a first episode of variceal bleeding (odds ratio 3.9; 95% confidence interval 1.2-13.9, p = 0.01), but was not significant in the subgroups of patients with a recurrent episode of variceal bleeding. The use of aspirin was associated with a high risk of a first episode of variceal bleeding, suggesting that patients with portal hypertension should avoid taking these drugs.

Gastrointestinal bleeding

A systemic approach must be taken with both upper and lower gastrointestinal bleeding. The first priority is stabilization. Once this has been achieved, and in patients who present with stable vital signs, a systematic approach to diagnosis and management must be followed. The urgency with which this is performed will be dictated by such aspects as risk factors and the clinical presentation. Some patients may need immediate diagnostic studies in the emergency department, some in the intensive care unit, some on a regular floor, and others may even be able to receive medical treatment followed by investigation on an outpatient basis.

Toxicity of nonsteroidal anti-inflammatory drugs in the large intestine

PURPOSE

Adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDS) on the upper gastrointestinal (GI) tract and small intestine are well described. Evidence is also accumulating that implicate NSAIDS in inducing and exacerbating damage in the distal GI tract. The purpose of this review is to identify possible adverse effects of NSAIDS on the large intestine and increase the clinical awareness of these toxicologic effects.

METHODS

A literature review identified the diversity of toxicologic effects induced by NSAIDS in the large intestine. The epidemiology, pathogenesis, and clinical implications of these adverse effects are described.

RESULTS

NSAID use has been associated with colonic bleeding, iron deficiency anemia, strictures, ulcerations, perforations, diarrhea, and death. In addition, NSAIDS can exacerbate inflammatory bowel disease and ulcerative colitis. The prevalence of NSAID-induced large intestinal damage is unknown. Diagnosis can be made by colonoscopy and barium scans. Although the clinical presentation of NSAID-induced gastropathy and enteropathy, bleeding or perforation, may be more dramatic than colonopathy, the overall clinical significance of these adverse effects of NSAIDS on the large intestine has not been fully characterized.

CONCLUSIONS

This review illustrates that NSAID-induced large bowel toxicity can cause significant morbidity in some patients, ranging from profuse diarrhea, chronic blood loss, and iron deficiency anemia to fatality. The pathogenesis is likely multifactorial and is thought to be related to inhibition of prostaglandin synthesis. Because NSAIDS are widely prescribed and some are available without a prescription, heightened awareness of these toxicologic manifestations throughout the GI tract may reduce morbidity.

Selective inhibition of fatty acid oxidation in colonocytes by ibuprofen: a cause of colitis?

Ibuprofen is associated with initiation or exacerbation of ulcerative colitis. As ibuprofen selectively inhibited fatty acid oxidation in the liver or caused mitochondrial damage in intestinal cells, its effect on substrate oxidation by isolated colonocytes of man and rat was examined. Ibuprofen dose dependently (2.0-7.5 mmol/l) and selectively inhibited 14CO2 production from labelled n-butyrate in colonocytes from the proximal and distal human colon (n = 12, p = < 0.001). Glucose oxidation was either unaltered or increased. Because short chain fatty acid oxidation is the main source of acetyl-CoA for long chain fatty acid synthesis, the inhibition of prostaglandin synthesis by ibuprofen in the colonic mucosa could also occur at this level. Because the concentrations of ibuprofen that can be attained in the human colon are not known, conclusions drawn from current dosages are tentative. The inhibition of fatty acid oxidation by ibuprofen may be biochemically implicated in the initiation and exacerbation of ulcerative colitis, manifestation of which would depend on the ibuprofen concentrations reached in the colon.

Adverse Gastrointestinal Effects of Nonsteroidal Anti-Inflammatory Drugs

There are a substantial number of adverse reactions attributable to nonsteroidal anti-inflammatory drug (NSAID) therapy, particularly of the gastrointestinal (GI) tract. The stomach is most commonly affected, although injury may occur from esophagus to colon. The incidence of developing serious GI toxicity seems to be three times as great in users compared with nonusers of NSAIDs. Age greater than 60 years, history of GI problems, previous corticosteroid use, and recency of NSAID use seem to increase the risk of toxicity. Short-term studies have found differences in ulceration or bleeding caused by various NSAIDs. However, there are insufficient long-term clinical trials involving adequate numbers of patients to demonstrate substantial advantages for any particular NSAID based on its toxicity profile. Prostaglandin inhibition seems to be one mechanism responsible for the GI toxicity of NSAIDs, but it is probably not the only mechanism. When serious GI bleeding occurs, the NSAID use must be stopped, although omeprazole and misoprostol have been used successfully to treat gastroduodenal ulcerations in patients while continuing NSAID therapy. Misoprostol and possibly omeprazole have effectively prevented GI ulceration associated with NSAID therapy, but questions remain regarding patient selection, length of therapy, and their utility in preventing serious GI bleeding. At this time, routine prophylaxis for patients receiving long-term NSAID therapy cannot be recommended.

Markedly reduced intestinal toxicity of a diclofenac derivative

Addition of a nitroxybutyl moiety to diclofenac greatly reduces its damaging effects on the gastric mucosa without altering its ability to suppress prostaglandin synthesis and exert anti-inflammatory actions. The present study was performed in order to determine if this derivative of diclofenac, called nitrofenac, would also have less toxicity in the small and large intestine when administered repeatedly over a 1-2 week period. Healthy rats were given equimolar doses of diclofenac (10 mg/kg) or nitrofenac (15 mg/kg) twice daily for up to two weeks. All 10 rats receiving diclofenac died prior to completion of the study, exhibiting massive small intestinal ulceration and perforation. No deaths were observed in the rats treated with nitrofenac, and the only small intestinal abnormality observed was diffuse hyperemia. As nonsteroidal anti-inflammatory drugs have been shown to exacerbate colitis, we compared the effects of twice daily treatment with diclofenac (1-10 mg/kg) or nitrofenac (1.5-15 mg/kg) for 1 week in rats in which colitis had been induced with trinitrobenzene sulfonic acid. Diclofenac administration resulted in mortality which increased dose-dependently (e.g. 86% at 5 mg/kg) and was associated with perforation of the colon. Mortality was not observed with nitrofenac at doses of 1.5 or 7.5 mg/kg, while at 15 mg/kg the mortality rate was 33%. None of the doses of nitrofenac significantly augmented colonic injury or granulocyte infiltration (measured by myeloperoxidase activity). Suppression of colonic prostaglandin E2 synthesis was comparable with equimolar doses of diclofenac and nitrofenace. These studies demonstrate that nitrofenac has markedly reduced intestinal toxicity in healthy and colitic rats when compared to diclofenac.