Effect of nonsteroidal anti-inflammatory drugs on the gastrointestinal tract: diagnosis by wireless capsule endoscopy

The Many Faces of Medication-Related Injury in the Gastrointestinal Tract

Every year many new medications are approved for clinical use, several of which can cause clinically significant gastrointestinal tract toxicity. This article emphasizes the histologic features and differential diagnosis of drug-induced injury to the gastrointestinal mucosa. Ultimately, clinical correlation and cessation of a drug with resolution of symptoms are needed to definitively confirm a drug as a causative factor in mucosal injury. Recognizing histologic features in gastrointestinal biopsies, however, can allow surgical pathologists to play a key role in establishing a diagnosis of drug-induced gastrointestinal toxicity.

Role of small bowel capsule endoscopy in the diagnosis and management of iron deficiency anemia in elderly: A comprehensive review of the current literature

Iron deficiency anemia (IDA) is common and often under recognized problem in the elderly. It may be the result of multiple factors including a bleeding lesion in the gastrointestinal tract. Twenty percent of elderly patients with IDA have a negative upper and lower endoscopy and two-thirds of these have a lesion in the small bowel (SB). Capsule endoscopy (CE) provides direct visualization of entire SB mucosa, which was not possible before. It is superior to push enteroscopy, enteroclysis and barium radiography for diagnosing clinically significant SB pathology resulting in IDA. Angioectasia is one of the commonest lesions seen on the CE in elderly with IDA. The diagnostic yield of CE for IDA progressively increases with advancing age, and is highest among patients over 85 years of age. Balloon assisted enteroscopy is used to treat the lesions seen on CE. CE has some limitations mainly lack of therapeutic capability, inability to provide precise location of the lesion and false positive results. Overall CE is a very safe and effective procedure for the evaluation of IDA in elderly.

Small bowel injury induced by selective cyclooxygenase-2 inhibitors: a prospective, double-blind, randomized clinical trial comparing celecoxib and meloxicam

BACKGROUND

Selective cyclooxygenase (COX)-2 inhibitors are less harmful to the small bowel mucosa than non-selective anti-inflammatory drugs. We aimed to compare the severity of small bowel mucosal injury in healthy volunteers induced by two selective COX-2 inhibitors, celecoxib and meloxicam, in a randomized, double-blind trial, using capsule endoscopy (CE).

METHODS

Twenty-nine healthy subjects were randomized to take either celecoxib (200 mg twice daily) or meloxicam (10 mg once daily) for 2 weeks. The incidence and the number of small bowel mucosal injuries (bleeding, ulcers, and erosions) observed by CE were compared between the two groups.

RESULTS

The overall incidence of small bowel mucosal injury was not different between the celecoxib group (6 of 14 subjects, 42.9%) and the meloxicam group (4 of 15 subjects, 26.7%, P = 0.45). In subjects with positive CE findings, the number of ulcers was greater in the meloxicam group than in the celecoxib group (P = 0.02), while such a trend was not found with regard to erosions (P = 0.52). The distribution of mucosal lesions within the small bowel was similar in the two groups.

CONCLUSIONS

Selective COX-2 inhibitors are not completely safe for the small bowel. The mucosal lesions may be less severe with celecoxib than with meloxicam.

Capsule endoscopy in celiac disease

Capsule endoscopy (CE) has been increasingly used for diagnosing disease of the small bowel. It is an attractive technique for assessing celiac disease (CD) because it is noninvasive and provides a close and magnified view of the mucosa of the entire small bowel. The aim of this paper is to update the current data on the use of CE for diagnosing villous atrophy and complications of CD.

Soluble dietary fiber protects against nonsteroidal anti-inflammatory drug-induced damage to the small intestine in cats

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) often cause ulcers in the small intestine in humans, but there are few effective agents for treatment of small intestinal ulcers. We found that soluble dietary fibers (SDFs), such as pectin, could prevent the formation of small intestinal lesions induced by indomethacin (IND) in cats. To elucidate the mechanism of protection by SDFs, we examined the viscosities of SDFs and the effects of pectin on gastrointestinal absorption of IND and intestinal hypermotility induced by IND.

METHODS

Cats were given regular dry food (RFD-Dry) or RFD-Dry supplemented with pectin, guar gum, polydextrose, or mucin twice daily. IND was administered orally once daily for 3 days. Mucosal lesions in the small intestine were examined 24 h after the final dosing of IND. Plasma concentrations of IND were measured by HPLC. GI motilities were measured using a telemetry system in conscious cats implanted with force transducers. Viscosities of the SDFs were measured using a viscosimeter.

RESULTS

In cats given RFD-Dry, IND (3 mg/kg) increased motility and produced many lesions in the lower half of the small intestine; the total lesion area (TLA) was 7.5 +/- 2.6 cm(2) (n = 4). Lesions induced by IND were markedly decreased in cats given RFD-Dry supplemented with 3% pectin, guar gum, polydextrose or mucin; TLAs were 0.6 +/- 0.3, 0.0 +/- 0.0, 1.3 +/- 0.8 and 1.6 +/- 0.5 cm(2) (n = 4) (P < 0.05 vs. RFD-Dry alone), respectively. The viscosity (mPa-S) of pectin, guar gum, polydextrose and mucin (3% concentration) was 414, >1,200, 1 and 4, respectively. Pectin did not affect the absorption of IND nor did it inhibit IND-induced intestinal hypermotility.

CONCLUSIONS

SDFs protect the small intestine against NSAID-induced damage, probably by compensating a barrier function of the mucin decreased by IND. Viscosities of the SDFs play a role, at least in part, in the protective effects of the SDFs on the small intestine.

Pharmacological treatment of chronic pain - the need for CHANGE

BACKGROUND

Although chronic pain affects around 20% of adults in Europe and the USA, there is substantial evidence that it is inadequately treated. In June 2009, an international group of pain specialists met in Brussels to identify the reasons for this and to achieve consensus on strategies for improving pain management.

SCOPE

Literature on chronic pain management was reviewed, and information presented to and discussed by a panel of experts.

FINDINGS

It was agreed that guidelines are not universally accepted by those involved in pain management, and pain treatment seems to be driven mainly by tradition and personal experience. Other factors include poor communication between patients and physicians, the side effects of analgesic drugs, and limited individualisation of therapy. Difficulty in maintaining the balance between adequate pain relief and acceptable tolerability, particularly with strong opioids, can lead to the establishment of a 'vicious circle' that alternates between lack of efficacy and unpleasant side effects, prompting discontinuation of treatment. The medical community's understanding of the physiological differences between nociceptive pain and neuropathic pain, which is often more severe and difficult to treat, could be improved. Increasing physicians' knowledge of the pharmacological options available to manage these different pain mechanisms offers the promise of better treatment decisions and more widespread adoption of a multi-mechanistic approach; this could involve loosely combining two substances from different drug classes, or administering an analgesic with two different mechanisms of action. In some circumstances, a single compound capable of addressing both nociceptive and neuropathic pain is desirable.

CONCLUSIONS

To improve patient outcomes, a thorough understanding of pain mechanisms, sensitisation and multi-mechanistic management is required. Universal, user-friendly educational tools are therefore required to familiarise physicians with these topics, and also to improve communication between physicians and their pain patients, so that realistic expectations of treatment can be established.

Capsule endoscopy: technique and indications

Since it was introduced in 2000, capsule endoscopy has become the gold standard for endoscopic examination of the small bowel in several clinical situations such as obscure gastrointestinal bleeding, suspicion of Crohn's disease, and surveillance of polyposis syndromes. In this technique a miniaturised endoscope, embedded in a swallowable capsule, is propelled through the gut by peristalsis and reaches the right colon in 5-8h. Images captured by the capsule are recorded on a hard drive in a belt worn by the patient. In addition to the extensive literature currently available on small bowel CE, new capsule devices are currently under evaluation for the examination of the colon with the purpose of screening for colorectal cancer, and of the oesophagus for screening for oesophageal varices and Barrett's oesophagus. These latter indications currently remain under evaluation. This review considers the technical aspects of capsule endoscopy and discusses the indications. Issues of safety and tolerance are also discussed.

Video capsule enteroscopy in the diagnosis of celiac disease: a multicenter study

OBJECTIVES

Duodenal biopsy is the current gold standard for diagnosis of celiac disease. Videocapsule endoscopy examines the entire small bowel and allows visualization of mucosal villi. We evaluated the potential of videocapsule endoscopy in assessing the severity and extent of mucosal changes in patients with suspected celiac disease.

METHODS

Consecutive patients with signs/symptoms suggesting celiac disease and positive anti-gliadin and/or anti-endomysial and/or anti-tissue transglutaminase antibodies underwent upper gastrointestinal endoscopy and videocapsule endoscopy. Duodenal biopsies were classified according to modified Marsh's criteria. Capsule findings were evaluated for the presence of lesions compatible with celiac disease (scalloping of duodenal folds, fissures, flat mucosa, and mosaic appearance).

RESULTS

Forty-three patients were studied. Duodenal histology was normal in 11 and compatible with celiac disease in 32. Using duodenal histology as the gold standard, the performance characteristics of capsule endoscopy for the diagnosis of celiac disease were: sensitivity 87.5% (95% CI 76.1-98.9%), specificity 90.9% (95% CI 81.0-100%), positive predictive value 96.5% (95% CI 90.1-100%), negative predictive value 71.4% (95% CI 55.8-87%), positive and negative likelihood ratios 9.6 and 0.14, respectively. Eighteen patients had mucosal changes extending beyond the duodenum, involving the entire small bowel in three. These patients tended to have more severe symptoms, but the difference was not statistically significant. Interobserver agreement for the diagnosis of celiac disease by capsule endoscopy ranged between 79.2 and 94.4%; kappa values ranged between 0.56 and 0.87.

CONCLUSIONS

Videocapsule endoscopy shows good sensitivity and excellent specificity for the detection of villous atrophy in patients with suspected celiac disease.

Findings in patients with chronic intestinal dysmotility investigated by capsule endoscopy

Background

Capsule endoscopy (CE) is a unique tool to visualize the mucosa of the small intestine. Chronic intestinal dysmotility (CID) is a group of rare disorders of gastrointestinal motility that often are complicated by bacterial overgrowth. The aim of this study was to determine the prevalence of small bowel mucosal abnormalities in patients with CID. We also studied the usefulness of CE in the diagnosis of intestinal dysmotility.

Methods

We conducted a prospective study using CE in 18 patients; six with myopathic, 11 with neuropathic and one with indeterminate CID. A control group was used for comparison of small bowel transit.

Results

Mucosal breaks (erosions and ulcerations) were found in 16/18 (89%) patients. The capsule reached the caecum in 11/18 (61%) patients with a median transit time of 346 minutes. In the control group the capsule reached the caecum in 29/36 (81%) cases with a median transit time of 241 minutes. The difference in transit time was not significant (p = 0.061) in this material. The capsule was retained in the stomach in 3/18 patients. None of the patients developed symptoms or signs of mechanical obstruction.

Conclusion

A high frequency of mucosal breaks and signs of motility disturbances were seen in CID patients. CE is feasible for the examination of small bowel mucosa in patients with CID. The relevance of observed mucosal abnormalities in CID remains uncertain.

Diagnosis of small-bowel diseases in the era of capsule endoscopy

Capsule endoscopy is a major breakthrough in gastrointestinal endoscopy and is a first-line tool to detect abnormalities of the small bowel, in up to 50% of patients, intestinal disorders are not associated with any physical findings or positive tests. Indications, yield and impact on patient management of this method of diagnosing small-bowel diseases are analyzed critically in light of current scientific knowledge.

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

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

Rifaximin, a poorly absorbed antibiotic: pharmacology and clinical potential

Rifaximin (4-deoxy-4'-methylpyrido[1',2'-1,2]imidazo- [5,4-c]-rifamycin SV) is a synthetic antibiotic designed to modify the parent compound, rifamycin, in order to achieve low gastrointestinal (GI) absorption while retaining good antibacterial activity. Both experimental and clinical pharmacology clearly show that this compound is a nonsystemic antibiotic with a broad spectrum of antibacterial action covering Gram-positive and Gram-negative organisms, both aerobes and anaerobes. Being virtually nonabsorbed, its bioavailability within the GI tract is rather high with intraluminal and fecal drug concentrations that largely exceed the minimal inhibitory concentration values observed in vitro against a wide range of pathogenic organisms. The GI tract represents, therefore, the primary therapeutic target and GI infections the main indication. The appreciation of the pathogenic role of gut bacteria in several organic and functional GI diseases has increasingly broadened its clinical use, which is now extended to hepatic encephalopathy, small intestine bacterial overgrowth, inflammatory bowel disease and colonic diverticular disease. Potential indications include the irritable bowel syndrome and chronic constipation, Clostridium difficile infection and bowel preparation before colorectal surgery. Because of its antibacterial activity against the microorganism and the lack of strains with primary resistance, some preliminary studies have explored the rifaximin potential for Helicobacter pylori eradication. Oral administration of this drug, by getting rid of enteric bacteria, could also be employed to achieve selective bowel decontamination in acute pancreatitis, liver cirrhosis (thus preventing spontaneous bacterial peritonitis) and nonsteroidal anti-inflammatory drug (NSAID) use (lessening in that way NSAID enteropathy). This antibiotic has, therefore, little value outside the enteric area and this will minimize both antimicrobial resistance and systemic adverse events. Indeed, the drug proved to be safe in all patient populations, including young children. Although rifaximin has stood the test of time, it still attracts the attention of both basic scientists and clinicians. As a matter of fact, with the advancement of the knowledge on microbial-gut interactions in health and disease novel indications and new drug regimens are being explored. Besides widening the clinical use, the research on rifaximin is also focused on the synthesis of new derivatives and on the development of original formulations designed to expand the spectrum of its clinical use.

Capsule endoscopy: current indications and future prospects

Capsule endoscopy represents a significant advance in the investigation of small bowel diseases and the beginning of wireless endoscopic imaging. Capsule endoscopy involves swallowing a video capsule endoscope, which is painless and relatively safe. Its use has been established for suspected small bowel bleeding, and the role of capsule endoscopy in the investigation of inflammatory bowel disease, iatrogenic disease, polyposis syndromes and coeliac disease is evolving. It is likely that in many instances it will become the next test after standard endoscopic evaluation. Early data suggest that capsule endoscopy improves outcome in patients with suspected small bowel bleeding, but more data are required on outcomes for the other indications.