Reviews in gastroenterological disorders最新文献

In 2007, the American College of Gastroenterology published updated treatment guidelines for the management of Helicobacter pylori infection, the leading cause of peptic ulcers. The recommended effective therapies are a triple drug regimen for 14 days or a quadruple bismuth therapy for 10 to 14 days, which includes a combination of a proton pump inhibitor such as omeprazole, bismuth, metronidazole, and tetracycline. These drug regimens all require strict adherence and several pills daily, but recent formulations have lessened the pill burden, which can improve patient compliance and outcomes. The pharmacology, product availability, efficacy, and potential adverse reactions of these regimens are discussed in this review.

Certolizumab pegol offers an alternative to the other biologic response modifiers for the treatment of Crohn's disease. Results from phase II dose-ranging studies were mixed because a number of the studies had high placebo response rates and a large number of patients with low C-reactive protein (CRP) levels. Phase III clinical trials have demonstrated induction of clinical responses and maintenance of remission for patients independent of whether baseline CRP levels were normal or elevated. Although concomitant immune suppressants reduced the immunogenicity, there were no differences in clinical response at 6 to 12 months for patients receiving immunosuppressives compared with those not receiving concomitant medications. There is also evidence that patients treated earlier in the course of disease may have improved responses and that patients who have lost response to infliximab will respond to certolizumab pegol.

Loperamide is an effective therapy for a variety of diarrheal syndromes, including acute, nonspecific (infectious) diarrhea; traveler's diarrhea; and chemotherapy-related and protease inhibitor?associated diarrhea. Loperamide is effective for the "gut-directed" symptom of diarrhea in patients with painless diarrhea or diarrhea-predominant irritable bowel syndrome. Loperamide and diphenoxylate are commonly used to treat diarrhea in numerous settings of inflammatory bowel disease. Loperamide has also been observed to increase anal sphincter tone, which may lead to improvement of fecal continence in patients with and without diarrhea. Loperamide is generally well tolerated at recommended nonprescription doses, with the most common side effects related to the impact on bowel motility (abdominal pain, distention, bloating, nausea, vomiting, and constipation).

Proton pump inhibitors (PPIs) are currently the most effective and most widely used agents for gastroesophageal reflux disease (GERD). Despite the efficacy of these agents in healing and symptom relief, a substantial proportion of patients require twice-daily therapy with PPIs, and break-through symptoms cause others to use over-the-counter antacids and histamine 2-receptor antagonists to supplement their PPI therapy. Major strategies that are being pursued include the development of agents that have a faster onset of action for on-demand therapy; have better control of acid secretion, resulting in improved healing in advanced grades of esophagitis and better symptom control; and agents that decrease transient lower esophageal sphincter relaxations (TLESRs), thereby reducing distal acid exposure and weakly acidic refluxate. A number of new pharmaceutical agents are currently undergoing clinical evaluation for the treatment of GERD. These include agents that reduce TLESRs, serotonergic agents/ prokinetics, long-acting PPIs, mucosal protectants, and antigastrin agents. One or more of these agents may be the future of GERD therapy.

For the examination of the small bowel in patients with suspected small bowel bleeding, endoscopic tools to perform deep enteroscopy have become essential. Double balloon enteroscopy has gained worldwide acceptance as an endoscopic technique that can be used safely and effectively to provide complete examination of the small bowel, offer therapeutic intervention, and favorably affect clinical outcomes. Single balloon enteroscopy seems to have utility similar to that of the double balloon system. Preliminary experience with a novel overtube device using either the single or double balloon enteroscope has suggested that this may be a very viable approach to deep enteroscopy. Collectively, these are remarkable innovations that allow access to portions of the small bowel that were previously only available by intraoperative enteroscopy or laparotomy. On the basis of the available data, each of these procedures seems to have unique merits, is generally safe and well tolerated, and is highly likely to be clinically beneficial.

Although the balance of epidemiologic data supports a relationship between obesity and gastroesophageal reflux disease (GERD), it is difficult to establish true cause and effect. However, results of several studies show that the frequency and severity of GERD symptoms and complications may be higher in obese patients, including an increase in the presence of hiatal hernia. Additionally, findings of a recent meta-analysis demonstrate a statistically significant increase in the risk for GERD symptoms, erosive esophagitis, and esophageal adenocarcinoma in obese patients. No definitive study is available, however, to suggest deviating from standard GERD screening or treatment guidelines for the obese patient. Physicians should approach obese patients with GERD as they do those with reflux disease and ideal body weight. The recommendation of weight loss for the obese patient with GERD is reasonable to improve GERD physiology and symptoms. Lifestyle modifications and medical therapy with a proton pump inhibitor (PPI) once daily before breakfast for 4 to 8 weeks should be initiated. Antireflux surgery is always an option for patients with GERD who have a symptomatic response to PPIs. Prospective studies directed at the obese patient are needed to determine if different approaches are required.

Clarithromycin resistance is a growing problem in many countries. Eradication rates for Helicobacter pylori have declined to unacceptable levels in recent years, in large measure because of clarithromycin resistance. Two treatment strategies (quadruple therapy and sequential therapy) are emerging as alternatives to triple therapy for the initial treatment of patients infected with H. pylori. Evidence shows that both quadruple therapy and sequential therapy are superior to triple therapy in patients with resistant strains of H. pylori. Studies that compare sequential and quadruple therapy are necessary and are awaited.

Technological advances in endoscopic imaging are constantly being evaluated in clinical research, and encouraging results are being seen. Studies on practical applications of these new technologies are ongoing in conditions as diverse as gastroesophageal reflux disease, Barrett's esophagus, colonic polyps, and dysplasia in ulcerative colitis. This review discusses the recent advances in endoscopic imaging that appear to be on the verge of widespread and routine usage. It is evident that high-resolution and high-definition white light endoscopy should be used when available, and is considered the new "gold standard" in endoscopic imaging. There is much optimism and ongoing research surrounding the use of narrow band imaging as well.