Safety of the long-term use of proton pump inhibitors

Are proton pump inhibitors associated with the development of community-acquired pneumonia? A meta-analysis

This study was presented at the American College of Chest Physicians meeting in Pittsburgh (PA, USA) in October 2011. The study objective was to evaluate the association of proton pump inhibitors (PPIs) and community-acquired pneumonia (CAP). The design was a meta-analysis of nine case-controlled and cohort studies. 120,863 pneumonia cases from 1987 to 2006 were included in the meta-analysis. PubMed and Ovid Medline were searched from inception through May 2011 by two investigators independently using keywords: PPI, pneumonia, CAP, anti-ulcer, antacid, omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole. This meta-analysis only included case-controlled and cohort studies that were published in full in English and evaluated PPI use and CAP incidence. Studies were excluded if they included the following patients: pediatric, Helicobacter pylori treatment and critically ill. Bibliographies of recent review articles and systematic reviews were hand-searched. Quality of studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Two investigators independently extracted data into standardized data collection forms that were confirmed by a third investigator. Data were analyzed based on current use of PPIs, duration of PPI use (<30 days or >180 days) and PPI dose (high vs low). Overall association of PPI and CAP was analyzed using the random effects model (Comprehensive Meta analysis(®) Version 2.0). Nine studies met all criteria for the primary outcome. Newcastle-Ottawa Quality Assessment Scale scores ranged from 4 to 8 out of 9. Current use of PPIs (odds ratio [OR]: 1.39; 95% CI: 1.09-1.76), PPI use <30 days (OR: 1.65; 95% CI: 1.25-2.19), PPI high dose (OR: 1.50; 95% CI: 1.33-1.68) and PPI low dose (OR: 1.17; 95% CI: 1.11-1.24) were significantly associated with CAP. There was no association between CAP and PPI use >180 days (OR: 1.10; 95% CI: 1.00-1.21). In conclusion, patients currently receiving PPIs, particularly <30 days or high dose, showed an association with CAP. Practitioners need to be vigilant about adverse effects of PPIs and consider alternative therapies.

Reflux and aerodigestive tract diseases

Gastroesophageal reflux disease can present with a wide variety of extraesophageal symptoms. In particular, the type of disease characterized predominately by laryngopharyngeal reflux may be difficult to diagnose because of the absence of regurgitation or heartburn. The available battery of diagnostic tools is often insufficient to confirm a diagnosis of reflux, so the diagnosis is often made by elimination. In many cases, treatment with proton pump inhibitors will relieve symptoms and respiratory complications, despite the persistence of non-acidic reflux. Such treatment is often employed to "confirm" the diagnosis, as measured by patient response. Many diseases have been related to this condition in the literature. The authors review knowledge about these manifestations and their relationship with refluxed gastric content. Physiopathology, symptoms and treatment are reviewed in order to clarify our understanding of laryngopharyngeal reflux diseases and related manifestations.

Clostridium difficile-associated diarrhea and proton pump inhibitor therapy: a meta-analysis

OBJECTIVES

Clostridium difficile-associated diarrhea (CDAD) is a major cause of morbidity and increasing health-care costs among hospitalized patients. Although exposure to antibiotics remains the most documented risk factor for CDAD, attention has recently been directed toward a plausible link with proton pump inhibitors (PPIs). However, the results of studies on the association between CDAD and PPIs remain controversial. We have conducted a meta-analysis to summarize the association between PPIs and CDAD among hospitalized patients.

METHODS

A systematic search of published literature on studies that investigated the association between PPIs and CDAD from 1990 to 2010 was conducted on Medline and PubMed. The identified articles were reviewed for additional references. The most adjusted risk estimates were extracted by two authors and summarized using random effects meta-analysis. We also conducted a subgroup analysis by study design. Publication bias was evaluated using the Begg and Egger tests. A sensitivity analysis using the Duval and Tweedie "trim-and-fill" method has also been performed.

RESULTS

Twenty-three studies including close to 300,000 patients met the inclusion criteria. There was a 65% (summary risk estimate 1.69 with a 95% confidence interval (CI) from 1.395 to 1.974; P<0.000) increase in the incidence of CDAD among patients on PPIs. By study design, whether case-control study (17) or cohort study (6), there was still a significant increase in the incidence of CDAD among PPI users. The risk estimates were 2.31 (95% CI from 1.72 to 3.10; P<0.001) and 1.48 (95% CI from 1.25 to 1.75; P<0.001) for cohort and case-control studies, respectively.

CONCLUSIONS

There is sufficient evidence to suggest that PPIs increase the incidence of CDAD. Our meta-analysis shows a 65% increase in the incidence of CDAD among PPI users. We recommend that the routine use of PPIs for gastric ulcer prophylaxis should be more prudent. Establishing a guideline for the use of PPI may help in the future with the judicious use of PPIs. Further studies, preferably prospective, are needed to fully explore the association between PPIs and CDAD.

Proton pump inhibitor therapy use does not predispose to small intestinal bacterial overgrowth

OBJECTIVES

Small intestinal bacterial overgrowth (SIBO) occurs due to alteration of the microbiota within the upper gastrointestinal tract. Proton pump inhibitor (PPI) therapy has been suggested as a risk factor for SIBO; however, the published reports have yielded conflicting results on the association between PPI therapy and risk of developing SIBO. The aim of this study was to compare the prevalence of SIBO as measured by glucose hydrogen breath testing (GHBT) in patients on PPI therapy compared with those not on PPI therapy.

METHODS

A retrospective chart review was completed for all patients who underwent GHBT testing from 2004 to 2010. Breath samples for hydrogen (H₂) and methane (CH₄) were collected before and every 20 min for 120 min following ingestion of a 50-g oral glucose load. We used the following criteria to define a positive GHBT (a) increase in H₂ > 20 parts per million (p.p.m.) over baseline, (b) sustained rise H₂ > 10 p.p.m. over baseline, (c) CH₄ > 15 p.p.m. over baseline, and (d) either rise H₂ > 20 p.p.m. over baseline or CH₄ > 15 p.p.m.

RESULTS

A total of 1,191 patients (70% female) were included, of whom 566 (48%) were on PPI therapy. GHBT positivity did not differ significantly between PPI users and nonusers by any of the diagnostic criteria used and PPI use was not significantly associated with GHBT positivity using any of these criteria. GHBT positivity was associated with older age (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.04) and antidiarrheal use (OR 1.99, 95% CI 1.15-3.44) using H₂ > 20, older age (OR 1.01, 95% CI 1.00-1.02) and diarrhea (OR 1.53, 95% CI 1.13-2.09) using H₂ > 10, and older age (OR 1.01, 95% CI 1.00-1.02) using either H₂ > 20 or CH₄ > 15. PPI use was not significantly associated with GHBT positivity using any of these criteria.

CONCLUSIONS

In this large, adequately powered equivalence study, PPI use was not found to be significantly associated with the presence of SIBO as determined by the GHBT.

Considerations for the use of proton-pump inhibitors in older adults

OBJECTIVE

To investigate current concerns regarding the use of proton-pump inhibitors (PPIs) in older adults.

DATA SOURCES

A literature search was conducted in MEDLINE (1948 to April week 3 2011) to identify relevant publications. Key words searched included proton-pump inhibitor, safety, adverse events, elderly, and older adults. Additional data sources were obtained through a bibliographic review of selected articles.

DATA SELECTION

Relevant studies conducted in older adults published in English that examined risks associated with the use of PPIs were included in this review.

DATA SYNTHESIS

The older adult population in the United States is growing at an astounding rate. With the increase in age, there are many factors that make the elderly susceptible to acid-related gastrointestinal disorders that require treatment with PPIs. However, PPI use in the elderly has been shown to lead to a number of health concerns. Recent data have shown that PPI use is associated with an increased risk of fractures, Clostridium difficile infection, community-acquired pneumonia, vitamin and mineral deficiencies, and drug interactions. These concerns will be further investigated and weighed against the benefits of PPI use in this population.

CONCLUSIONS

Patient-specific characteristics must be taken into consideration when recommending and/or prescribing PPIs to older adults.

Severe sustained cholestatic hepatitis following temozolomide in a patient with glioblastoma multiforme: case study and review of data from the FDA adverse event reporting system

Glioblastoma multiforme (GBM) is the most frequent malignant brain tumor in adults. Its established first-line adjuvant treatment is radiotherapy in combination with temozolomide (TZM). Hematotoxicity is listed as a frequent adverse drug reaction in the US prescribing information and hepatotoxicity has been reported infrequently in the postmarketing period. We here present the case of a patient diagnosed with GBM who developed severe sustained cholestatic hepatitis following treatment with TZM. The cholestasis was not reversible after withdrawal of TZM during 6 months before the patient's death. Another 2 published case reports of sustained cholestasis following TZM treatment were identified; however, the sustained nature of cholestasis was not emphasized in these reports. Sixteen cases of cholestatic hepatitis/cholestasis associated with TZM were identified in the FDA spontaneous reporting system between 2007 and 2010. Information on the course of the cholestasis in these cases could not be retrieved. In the literature there are other published reports of hepatotoxicity associated with TZM that have reported reversibility upon withdrawal of the drug. Thus, TZM appears to cause different types of hepatotoxicity. Particular attention should be paid to sustained cholestasis as a very serious type of TZM-associated liver toxicity.

Vitamin B12 deficiency in Australian residential aged care facilities

OBJECTIVE

To determine the prevalence of undiagnosed vitamin B12 deficiency among residential aged care facility residents in southern Tasmania, Australia, and to identify associated risk factors.

DESIGN AND SETTING

Cross-sectional study of residents from five southern Tasmanian residential aged care facilities.

PARTICIPANTS

Two hundred and fifty-nine residents without a prior diagnosis of vitamin B12 deficiency or recorded serum B12 level within the past 6 months were approached to have their serum B12 level tested. One hundred and sixty (61%) residents consented and their doctors were contacted for further consent. A total of 130 (50%) residents completed the study.

MEASUREMENTS

Clinical and demographic characteristics, and serum B12 level.

RESULTS

Of the 130 residents tested, 18 residents (14%) were considered vitamin B12 deficient (serum level <150 pmol/L), 47 (36%) were equivocal (150 pmol/L to 250 pmol/L) and 65 (50%) had normal serum B12 levels (>250 pmol/L). There was a weak negative correlation between age and serum B12 level in those residents not taking a multivitamin (n=120, r=-0.19, p<0.05). The use of a multivitamin or antipsychotic drug were associated with altered mean serum B12 levels (+137 pmol/L, p<0.001 and -70 pmol/L, p<0.001 respectively).

CONCLUSION

As vitamin B12 deficiency can manifest in a range of symptoms that are frequently misdiagnosed, the finding of undetected deficiency in 14% of residents is a cause for concern. Oral multivitamin supplementation may help prevent deficiency, and potentially treat existing deficiencies in older institutionalised people.

Clinical utility of esomeprazole for treatment of gastroesophageal reflux disease in pediatric and adolescent patients

Gastroesophageal reflux is a common condition in the pediatric population, with an increasing incidence in the last few years. It can be defined as an effortless retrograde movement of gastric contents into the esophagus related to complex multifactorial pathogenesis, involving anatomical, hormonal, environmental, and genetic factors. In some cases, it may be associated with esophageal or extraesophageal symptoms (heartburn and regurgitation), and is defined as gastroesophageal reflux disease (GERD). The therapeutic approach to gastroesophageal reflux in infants and children is often conservative, including changes in lifestyle (eg, posture and thickening of meals). If these children remain symptomatic after lifestyle changes (nutrition, feeding, and positional modification), or present with clinical red flags (poor weight gain, recurrent respiratory symptoms, or hematemesis) and complications of GERD (esophagitis, bleeding, stricture, Barrett’s esophagus, or adenocarcinoma) it may be necessary to set up a proper diagnostic protocol. Proton pump inhibitors have been recommended as the most effective acid suppression therapy for adults and pediatric patients. Esomeprazole, the S-isomer of omeprazole, is the only single-isomer proton pump inhibitor available. The paper assesses the safety and tolerability of esomeprazole in pediatric and adolescent patients.

Effect of fluoxetine on the pharmacokinetics of lansoprazole: a two-treatment period study in healthy male subjects

BACKGROUND

Fluoxetine is an inhibitor of the main metabolizing enzymes of lansoprazole and could influence the pharmacokinetics of lansoprazole. The changes in lansoprazole pharmacokinetics could have clinical significance concerning the safety of the therapy.

OBJECTIVE

The aim of this study was to evaluate the pharmacokinetic interaction between fluoxetine and lansoprazole in healthy subjects.

METHODS

A dose of lansoprazole 30 mg, alone or in combination with fluoxetine 60 mg, was administered to 18 healthy male subjects in a two-treatment study design, separated by an 8-day period in which fluoxetine alone was administered as a single oral daily dose. Plasma concentrations of lansoprazole were determined during a 12-hour period following drug administration. Lansoprazole plasma concentrations were determined by a validated liquid chromatography-mass spectrometry method. The pharmacokinetic parameters of lansoprazole were calculated using non-compartmental analysis.

RESULTS

In the two periods of treatment, the mean maximum plasma concentration (C(max)) values were 817 ng/mL (lansoprazole alone) and 1370 ng/mL (lansoprazole in combination with fluoxetine after pre-treatment with fluoxetine for 8 days) [p < 0.0001]. The observed area under the plasma concentration-time curve (AUC) from time zero to time of last measurable concentration values were 2400 and 6220 ng · h/mL (p < 0.0001), respectively, and the AUC from time zero to infinity values were 2480 and 7290 ng · h/mL (p < 0.0001), respectively. The time to reach C(max) values were 2.72 and 2.64 hours, respectively. The elimination rate constant from the central compartment values were 0.50 and 0.21 h-1, respectively (p < 0.0001). The elimination half-life values were 1.47 and 3.56 hours (p < 0.0001), respectively, and the mean residence times were 4.0 and 6.9 hours (p < 0.0001), respectively.

CONCLUSION

The data demonstrate a pharmacokinetic interaction between fluoxetine and lansoprazole and suggest that the observed interaction may be clinically significant, although its clinical relevance has yet to be confirmed.

Cotreatment with dichloroacetate and omeprazole exhibits a synergistic antiproliferative effect on malignant tumors

It has been reported that treating cancer cells with dichloroacetate (DCA), an approved treatment for congenital lactic acidosis, reverses the Warburg effect and inhibits tumor growth). Furthermore, omeprazole (OMP) is a well-known agent that enhances the effects of anticancer drugs. The aim of this study was to find clinically-used drugs that enhance the effects of DCA. The combination of DCA and OMP exhibited a more potent antitumor activity than DCA alone in HT1080 fibrosarcoma cells and RKO colon cancer cells, while the drugs did not affect the proliferation of WI-38 human fibroblasts. The inhibitory effect of DCA combined with OMP was reversed with vitamin E and Z-VAD-FMK; therefore conventional caspase-dependent cell growth inhibition through superoxide production was suggested as the mechanism for inhibition. The combination of these drugs also had an effect on HT1080 fibrosarcoma cells inoculated into mice. Since OMP and DCA may be administered orally and have been used clinically for several years without major side effects, we believe that this combination therapy could be readily translated to treat malignant tumors.

Lansoprazole for secondary prevention of gastric or duodenal ulcers associated with long-term non-steroidal anti-inflammatory drug (NSAID) therapy: results of a prospective, multicenter, double-blind, randomized, double-dummy, active-controlled trial

BACKGROUND

Low-dose lansoprazole has not been intensively evaluated for its efficacy in the prevention of recurrent gastric or duodenal ulcers in patients receiving long-term non-steroidal anti-inflammatory drug (NSAID) therapy for pain relief in such diseases as rheumatoid arthritis, osteoarthritis, and low back pain.

METHODS

This multi-center, prospective, double-blind, randomized, active-controlled study involving 99 sites in Japan was designed to compare the efficacy of lansoprazole (15 mg daily) with gefarnate (50 mg twice daily). Patients with a history of gastric or duodenal ulcers who required long-term NSAID therapy were randomized to receive lansoprazole 15 mg daily (n = 185) or gefarnate 50 mg twice daily (n = 181) and followed up for 12 months or longer prospectively.

RESULTS

The cumulative incidence of gastric or duodenal ulcer at days 91, 181, and 361 from the start of the study was calculated by the Kaplan-Meier method as 3.3, 5.9, and 12.7%, respectively, in the lansoprazole group versus 18.7, 28.5, and 36.9%, respectively, in the gefarnate group. The risk for ulcer development was significantly (log-rank test, P < 0.0001) lower in the lansoprazole group than in the gefarnate group, with the hazard ratio being 0.2510 (95% CI 0.1400-0.4499). A long-term follow-up study showed an acceptable safety profile for low-dose lansoprazole therapy, with diarrhea as the most frequent adverse event.

CONCLUSION

Lansoprazole was superior to gefarnate in reducing the risk of gastric or duodenal ulcer recurrence in patients with a definite history of gastric or duodenal ulcers who required long-term NSAID therapy.

In vitro effect of pantoprazole on lower esophageal sphincter tone in rats

AIM: To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter (LES) tone.

METHODS: Rats weighing 250-300 g, provided by the Yeditepe University Experimental Research Center (YÜDETAM), were used throughout the study. They were anesthetized before decapitation. LES tissues whose mucosal lining were removed were placed in a standard 30-mL organ bath with a modified Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature. The tissues were allowed to stabilize for 60 min. Subsequently, the contractile response to 10^-6 mol/L carbachol was obtained. Different concentrations of freshly prepared pantoprazole were added directly to the tissue bath to generate cumulative concentrations of 5 × 10^-6 mol/L, 5 × 10^-5 mol/L, and 1.5 × 10^-4 mol/L. Activities were recorded on an online computer via a 4-channel transducer data acquisition system using the software BSL PRO v 3.7, which also analyzed the data.

RESULTS: Pantoprazole at 5 × 10^-6 mol/L caused a small, but statistically insignificant, relaxation in the carbachol-contracted LES (2.23% vs 3.95%). The 5 × 10^-5 mol/L concentration, however, caused a significant relaxation of 10.47% compared with the control. 1.5 × 10^-4 mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES (P < 0.001).

CONCLUSION: This is the first study to demonstrate that pantoprazole has a relaxing effect in isolated LESs. These results might have significant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.

Comparison of the efficacy and safety of pantoprazole magnesium and pantoprazole sodium in the treatment of gastro-oesophageal reflux disease: a randomized, double-blind, controlled, multicentre trial

BACKGROUND

Proton pump inhibitors (PPIs) are well established as first-line agents for the treatment of moderate-to-severe gastro-oesophageal reflux disease (GORD). Although all PPIs heal oesophageal lesions and provide symptomatic relief, breakthrough symptoms may occur as acidity levels rebound. Pantoprazole magnesium (pantoprazole-Mg) has a longer elimination half-life than pantoprazole sodium (pantoprazole-Na), resulting in prolonged drug exposure.

OBJECTIVE

This study compares the clinical efficacy and safety of once-daily pantoprazole-Mg 40 mg with that of once-daily pantoprazole-Na 40 mg in the management of GORD.

METHODS

This was a randomized, double-blind, controlled, multicentre study of non-inferiority design in outpatients with GORD. The study was conducted in 53 centres in Germany from 12 May 2003 to 18 September 2003. Male or female outpatients (aged ≥18 years) with endoscopically confirmed GORD stage I-III (according to the Savary-Miller classification modified by Siewert) were enrolled. Using a computer-generated randomization list, patients were randomized to treatment with pantoprazole-Mg 40 mg plus placebo or pantoprazole-Na 40 mg plus placebo, both given once daily for 4 or 8 weeks depending on healing of oesophagitis. The primary objective was endoscopic healing at 8 weeks.

RESULTS

The intent-to-treat (ITT) group consisted of 636 patients (322 receiving pantoprazole-Mg and 314 receiving pantoprazole-Na). Endoscopically confirmed healing of reflux oesophagitis after 8 weeks occurred in 87.3% (95% CI 83.1, 90.7) of patients receiving pantoprazole-Mg and 85.0% (95% CI 80.6, 88.8) of patients receiving pantoprazole-Na (ITT population). The lower bound of the 95% CI for the between-group treatment difference was -1.3, which was within the predefined margin of non-inferiority of -10% to 0%. Healing rates after 4 weeks were superior in the pantoprazole-Mg group (72.7% [95% CI 67.5, 77.5]) compared with the pantoprazole-Na group (66.2% [95% CI 60.7, 71.5]), and the one-sided (lower bound) of the 95% CI for the difference between healing rates for the two treatments was within the predefined non-inferiority margin of -10% to 0%. Both treatments had a similar effect on GORD healing in subgroups of patients based on baseline oesophagitis grade and Helicobacter pylori status. Pantoprazole-Mg had similar efficacy to pantoprazole-Na in relieving a broad range of GORD-related symptoms across the course of the study, although symptomatic relief at 4 weeks was numerically higher in the pantoprazole-Mg group than in the pantoprazole-Na group (statistical analyses were not performed). Both treatments were well tolerated; most adverse events were of mild or moderate severity and unrelated to the study medication, and there were no unexpected safety concerns.

CONCLUSION

Pantoprazole-Mg is clinically as effective and well tolerated as pantoprazole-Na in the treatment of GORD stages I-III, demonstrating non-inferiority for oesophageal healing at 8 weeks and superior healing rates at 4 weeks associated with high levels of symptomatic relief.

Update on the pharmacogenomics of proton pump inhibitors

Proton pump inhibitors (PPIs) are widely used for the treatment of gastroesophageal reflux disease as well as other acid-related disorders. PPIs are metabolized primarily via the CYP2C19 and CYP3A4 isoenzymes; their activity is influenced both by exogenous and endogenous (pharmacogenetic) factors. The CYP2C19 polymorphism affects the metabolism of PPIs, causing large individual pharmacokinetic variations. Differences in the CYP2C19-mediated metabolism can produce marked interpatient variability in acid suppression, in drug-interaction potential and in clinical efficacy. Understanding the pharmacokinetic properties of PPIs and examining the pharmacogenetic alterations may help clinicians optimize PPI therapy and administer individual treatment, especially to nonresponder patients with gastroesophageal reflux disease or ulcer or after failed eradication therapy.

Increased Vitamin B12 levels are associated with mortality in critically ill medical patients

BACKGROUND & AIMS

We describe an observational study in critically ill medical patients showing the association between serum Vitamin B12 levels measured on or near admission and the outcome in these patients.

METHODS

We used the database of patients admitted to the Medical Intensive Care Unit (MICU) at the Hadassah-Hebrew University Medical Center in Jerusalem, Israel, to analyze associations between patient demographics, background, diagnoses and serum Vitamin B12 levels with hospital and 90 day outcomes.

RESULTS

Higher mean Vitamin B12 levels were found in patients who did not survive their hospital stay (1719 pg/ml vs 1003 pg/ml, p < 0.01). Those who had died by 90 days after admission to the MICU also had higher Vitamin B12 levels than survivors (1593 pg/ml vs 990 pg/ml). Regression analysis showed that elevated Vitamin B12 levels were associated with increased 90 day mortality, even after controlling for other variables. Survival analysis also showed an increased mortality rate in patients with Vitamin B12 levels over 900 pg/ml (p < 0.0002).

CONCLUSIONS

Our data show that high serum Vitamin B12 levels are associated with increased mortality in critically ill medical patients. We suggest that Vitamin B12 levels should be included in the work-up of all medical intensive care patients, particularly those with a chronic health history and increased severity of illness.

Gradual cessation of proton pump inhibitor (PPI) treatment may prevent rebound acid secretion, measured by the alkaline tide method, in dyspepsia and reflux patients

Gastro esophageal reflux disease and ulcer related or non-ulcer dyspepsia, attacks 20% of the Western population. These millions of patients are treated continuously with PPI for different periods, many for many years. Recently, rebound acid hypersecretion was recognized as a major clinical event after cessation of PPI therapy. Sustained hypergastrinemia due to daily PPI therapy causes increased acid-secretory capacity that appears when the drug is stopped. The transient increase in blood and urinary pH following gastric secretion has been termed the alkaline tide phenomenon. Carbonic acid, formed in the presence of the enzyme carbonic anhydrase, neutralizes intracellular hydroxyl ions produced as a result of luminal acid secretion. The bicarbonate generated is removed from the cell via the baso-lateral chloride bicarbonate exchanger. We have shown in several studies that this phenomenon parallels acid secretion. Thus, stimulation of acid secretion with test meal increased base excess maximally after 45 min and these changes parallel peak acid output measured in gastric aspirate. We hypothesize that gradual step down cessation of PPI will prevent this clinical relevant event. By measuring alkaline tide after PPI cessation we may prove this hypothesis.

Development of quality measures for monitoring and improving care in gastroenterology

Over the past decade, most quality assurance (QA) efforts in gastroenterology have been aimed at endoscopy. Endoscopic quality improvement was the rational area to begin QA work in gastroenterology due to the relatively acute nature of complications and the high volume of procedures performed. While endoscopy is currently the focus of most quality assurance (QA) measures in gastroenterology, more recent efforts have begun to address clinical gastroenterology practices both in the outpatient and inpatient settings. Clinical outpatient and inpatient gastroenterology is laden with areas where standardization could benefit patient care. While data and experience in clinical gastroenterology QA is relatively limited, it is clear that inconsistent use of guidelines and practice variations in gastroenterology can lead to lower quality care. In this review, we review a variety of areas in clinical gastroenterology where existing guidelines and published data suggest both the need and practicality of active QA measures.

Omeprazole inhibits proliferation and modulates autophagy in pancreatic cancer cells

BACKGROUND

Omeprazole has recently been described as a modulator of tumour chemoresistance, although its underlying molecular mechanisms remain controversial. Since pancreatic tumours are highly chemoresistant, a logical step would be to investigate the pharmacodynamic, morphological and biochemical effects of omeprazole on pancreatic cancer cell lines.

METHODOLOGY/PRINCIPAL FINDINGS

Dose-effect curves of omeprazole, pantoprazole, gemcitabine, 5-fluorouracil and the combinations of omeprazole and 5-fluorouracil or gemcitabine were generated for the pancreatic cancer cell lines MiaPaCa-2, ASPC-1, Colo357, PancTu-1, Panc1 and Panc89. They revealed that omeprazole inhibited proliferation at probably non-toxic concentrations and reversed the hormesis phenomena of 5-fluorouracil. Electron microscopy showed that omeprazole led to accumulation of phagophores and early autophagosomes in ASPC-1 and MiaPaCa-2 cells. Signal changes indicating inhibited proliferation and programmed cell death were found by proton NMR spectroscopy of both cell lines when treated with omeprazole which was identified intracellularly. Omeprazole modulates the lysosomal transport pathway as shown by Western blot analysis of the expression of LAMP-1, Cathepsin-D and β-COP in lysosome- and Golgi complex containing cell fractions. Acridine orange staining revealed that the pump function of the vATPase was not specifically inhibited by omeprazole. Gene expression of the autophagy-related LC3 gene as well as of Bad, Mdr-1, Atg12 and the vATPase was analysed after treatment of cells with 5-fluorouracil and omeprazole and confirmed the above mentioned results.

CONCLUSIONS

We hypothesise that omeprazole interacts with the regulatory functions of the vATPase without inhibiting its pump function. A modulation of the lysosomal transport pathway and autophagy is caused in pancreatic cancer cells leading to programmed cell death. This may circumvent common resistance mechanisms of pancreatic cancer. Since omeprazole use has already been established in clinical practice these results could lead to new clinical applications.

Balloon-assisted enteroscopy with prophylactic polypectomy for Peutz-Jeghers syndrome: experience in Taiwan

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a very rare disease that often causes severe complications such as bowel obstruction or gastrointestinal tract bleeding. In the past, it was usually treated by using surgical intervention despite the associated complications. Balloon-assisted enteroscopy (BAE) has been documented as an effective and safe method for the diagnosis and treatment of small bowel lesions. Hence, we conducted this study to verify whether BAE is useful for patients with PJS.

AIM

To evaluate the safety and efficacy of BAE with prophylactic polypectomy in patients with PJS.

METHODS AND PATIENTS

From August 2005 to February 2010, 6 consecutive patients were diagnosed with PJS after pathological and clinical examination, and underwent BAE examination and polypectomy at Chang Gung Memorial Hospital, an academic tertiary referral center.

RESULTS

Six consecutive patients (4 men and 2 women) diagnosed with PJS underwent BAE with polypectomy. BAE was performed 17 times for complete examination of the entire small bowel. The range of the diameter of the removed polyps was 1-6 cm. No immediate complications such as hemorrhage or hollow organ perforation were noted during the procedure, and no patient developed intussusception during the follow-up period (32 ± 17.5 months).

CONCLUSION

BAE with polypectomy is useful for patients with PJS in order to reduce the complications of the condition.

Small intestinal vascular malformation bleeding: diagnosis by double-balloon enteroscopy combined with abdominal contrast-enhanced CT examination

Aim

The purpose of this study was to explore the value of double-balloon enteroscopy combined with abdominal vascular-enhanced CT examination for the diagnosis of intestinal vascular malformation bleeding, to explore a simple and effective method for the diagnosis of small intestinal vascular malformation bleeding.

Methods

Ten patients with intestinal bleeding were first examined with double-balloon enteroscopy. If active bleeding considered as vascular malformation was observed, the patient underwent abdominal vascular-enhanced CT examination. If no active bleeding was observed with double-balloon enteroscopy, the patient also underwent abdominal vascular-enhanced CT examination. When intestinal vascular malformation bleeding was diagnosed with double-balloon enteroscopy and/or abdominal vascular-enhanced CT examination, the patient underwent surgical operation and vascular malformation was confirmed with pathologic diagnosis.

Results

In ten patients who underwent double-balloon enteroscopy examination, active intestinal bleeding was observed in seven patients and no active bleeding was observed in three patients. All ten patients underwent abdominal vascular-enhanced CT examination and vascular malformation was detected in all the patients with confirmation by pathologic diagnosis.

Conclusion

Double-balloon enteroscopy combined with abdominal vascular enhanced CT examination is a simple and effective method for the diagnosis of intestinal vascular malformation bleeding.

Anti-acid medication as a risk factor for food allergy

An important feature for oral allergens is their digestion-resistance during gastrointestinal transit. For some oral allergens, digestion stability is an innate feature, whereas digestion-labile antigens may only persist in times of impairment of the digestive system. In this review, we collect evidence from mouse and human studies that besides the inherent molecular characteristics of a food protein, the stomach function is decisive for the allergenic potential. Gastric acid levels determine the activation of gastric pepsin and also the release of pancreatic enzymes. When anti-ulcer drugs inhibit or neutralize gastric acid, they allow persistence of intact food allergens and protein-bound oral drugs with enhanced capacity to sensitize and elicit allergic reactions via the oral route. Mouse studies further suggest that maternal food allergy arising from co-application of a food protein with anti-acid drugs results in a Th2-biased immune response in the offspring. Especially, anti-ulcer drugs containing aluminum compounds act as Th2 adjuvants. Proton pump inhibitors act on proton secretion but also on expression of the morphogen Sonic hedgehog, which has been related to the development of atrophic gastritis. On the other hand, atrophic gastritis and resulting hypoacidity have previously been correlated with enhanced sensitization risk to food allergens in elderly patients. In summary, impairment of gastric function is a documented risk factor for sensitization against oral proteins and drugs.

Association of long-term proton pump inhibitor therapy with bone fractures and effects on absorption of calcium, vitamin B12, iron, and magnesium

Proton pump inhibitors (PPI) are one of the most widely used classes of drugs. PPIs have a very favorable safety profile, and it is unusual for a patient to stop them because of side effects. However, with increasing numbers of patients chronically taking PPIs for gastroesophageal reflux disease and other common, persistent conditions, the long-term potential adverse effects are receiving increasing attention. An insufficiently studied area receiving much attention is the long-term effect of chronic acid suppression on the absorption of vitamins and nutrients. This increased attention results from the reported potential adverse effect of chronic PPI treatment leading to an increased occurrence of bone fractures. Interest in this area has led to examination of the effects of PPIs on calcium absorption/metabolism and numerous cohort, case-control, and prospective studies of their ability to affect bone density and cause bone fractures. In this article, these studies are systematically examined, as are studies of the effects of chronic PPI use on absorption of VB(12), iron, and magnesium. Studies in each area have led to differing conclusions, but when examined systematically, consistent results of several studies support the conclusion that long-term adverse effects on these processes can have important clinical implications.

A clinical perspective on gastric neuroendocrine neoplasia

The incidence of gastric neuroendocrine tumors (NETs) has increased exponentially based on widespread use of endoscopy and a greater pathological awareness of the condition. A key concern is the potential association with hypergastrinemia induced by proton pump inhibitor administration. Previous confusion regarding diagnosis and therapy has been diminished by a series of international consensus statements defining the biology and management strategies for the disease. Overall, gastric NETs are categorized as well-differentiated or poorly differentiated neoplasms. Well-differentiated gastric NETs are enterochromaffin-like (ECL) cell tumors subclassified into three types based on their relationship to gastrin, a key regulator of ECL cell neoplastic transformation. The treatment of type 1 and type 2 tumors depends on the size and invasiveness of the tumor, whereas type 3 tumors and poorly differentiated neuroendocrine carcinomas warrant aggressive surgical resection. The disease-specific 5-year survival ranges from about 95% in type 1 gastric carcinoids to about 25% in poorly differentiated gastric NECs. Elucidation of the precise biology of a gastric NET is critical to diagnosis and delineation of a type-specific management strategy.

[Role of Helicobacter pylori infection in iron deficiency anemia]

Anemia induced by digestive diseases refers to anemia due to iron deficiency. Conventional gastrointestinal diagnostic workup fails to establish the cause of iron deficiency in about one third of patients. Abnormal iron absorption is increasingly recognized as an important cause of unexplained iron deficiency. The importance of coeliac disease as a possible cause of iron deficiency anemia refractory to oral iron treatment, without other manifestations of malabsorption syndrome, is increasingly being recognized. In addition, Helicobacter pylori (HP) has been implicated in several recent studies as a cause of iron deficiency anemia (IDA) refractory to oral iron treatment. Cure of previously refractory IDA by HP eradication provides strong evidence supporting a cause-and-effect relationship. In order to establish a cause-and-effect relationship between HP gastritis and IDA, prospective randomized studies comparing the effects of iron administration with or without H. pylorieradication are highly recommended.

Short and long-term PPI treatment for GERD. Do we need more-potent anti-secretory drugs?

Because the reflux of the acidic gastric content into the esophagus plays a major role in the pathogenesis of symptoms of GERD and lesions of erosive esophagitis, acid suppression with a proton pump inhibitor (PPI) is currently the mainstay of anti-reflux therapy. There is a strong correlation between the degree of acid suppression provided by a given drug and its efficacy. The superiority of PPIs over other drugs (antacids, prokinetics and H(2)-receptor antagonists) has now been established beyond doubt, both for short- and long-term treatment. However, there are still some unmet therapeutic needs in GERD; hence, patients with non-erosive reflux disease (NERD) are less responsive to PPIs than those with erosive esophagitis. Moreover, the efficacy of PPIs in patients with atypical symptoms is frequently limited to the relief of associated heartburn or regurgitation. With respect to safety, although most studies on short- and long-term PPI use have provided reassuring data, recent reports have drawn attention to potential side effects or drug-drug interference. Better healing rates in the most severe forms of esophagitis, or a faster onset of symptom relief, may require optimization of acid suppressive therapy with regard to the daily course of acid secretion, especially during the night. Different pharmacological approaches can be considered, with the ultimate goals of achieving faster, stronger and more-sustained acid inhibition. How a better pharmacological profile may translate into clinical benefit should now be tested in appropriate, controlled studies.

Adverse effects of proton pump inhibitor drugs: clues and conclusions

PURPOSE OF REVIEW

To review evidence relating to the strength of associations that have appeared in largely observational studies, between high-dose or long-term use of proton pump inhibitor drugs and certain possibly attributable side-effects, which emerge from studies confounded by other variables. In retrospective studies not designed to assess safety, evidence of causality is generally lacking.

RECENT FINDINGS

The associations of fractures of hip, wrist, forearm and other sites appear weak and only slightly higher than the risks in control populations matched for age. They may increase with drug exposure, but probably do so only in individuals in whom other risk factors are also operational (smoking, alcohol, poor nutrition, steroids, etc.). The risks of Clostridium difficile colitis, other enteric infections, small bowel bacterial overgrowth and possibly spontaneous bacterial peritonitis also appear increased. Impaired gastric secretion may adversely affect the absorption of various nutrients, but their clinical impact is ill defined. Potentially more important are the consequences of hypergastrinemia, including rebound hypersecretion of acid, and possible development of various cancers, including carcinoid tumors. Effects of other drugs, including clopidogrel, on metabolism are reviewed, but clouded by uncertainties.

SUMMARY

The safety of long-term PPI administration needs serious prospective study.