How are Azathioprine and 6-mercaptopurine dosed by gastroenterologists? Results of a survey of clinical practice

BACKGROUND

Azathioprine (AZA) and 6-mercaptopurine (6-MP) are accepted as effective therapy for Crohn's disease and ulcerative colitis. Although general guidelines have been suggested for weight-based dosing of thiopurines, no standard of care has been established. Clinical trials have demonstrated efficacy for weight-based dosing of AZA at 2.5 mg/kg/day and 6-MP at 1.5 mg/kg/day. Escalation of dosing is recommended within 2 weeks of initiating therapy. The aim was to determine the prescribing practices of community practice gastroenterologists with respect to 6-MP/AZA dosing.

METHODS

Questionnaires were distributed via a mail database or during gastroenterology society meetings to gastroenterologists in NY, NJ, and CT. Questionnaires ascertained starting doses of AZA/6-MP, use of thiopurine methyltransferase (TPMT) enzyme testing, and strategy for dose optimization.

RESULTS

A total of 145 questionnaires were collected. Twenty-four percent of gastroenterologists escalated the dose within 2 weeks after initiating therapy. The majority used weight-based dosing as their target of therapy. Thirty-five percent reported measuring TPMT levels and 46% used metabolite monitoring.

CONCLUSIONS

Most gastroenterologists take longer than recommended to raise the dose of AZA/6-MP. Although the majority of gastroenterologists reported maximal dosages based on weight, there may be a delay in achieving this goal. Optimizing dosing of AZA/6-MP may improve efficacy and reduce the need to use additional therapy.

Mucosal tissue transglutaminase expression in celiac disease

Tissue transglutaminase (tTG) plays an important role in celiac disease pathogenesis and antibodies to tTG are a diagnostic marker of gluten-sensitive enteropathy. The aim of this study was to investigate the localization of tTG in the duodenal mucosa in control tissues and in different histological stages of celiac disease by using a commercial and a novel set of anti-tTG monoclonal antibodies, to see whether this assessment can be useful for diagnostic purpose. The distribution of tTG was firstly evaluated in 18 untreated celiac patients by using a commercial monoclonal antibody (CUB7402) against tissue transglutaminase enzyme and directed against the loop-core region of the enzyme. Thereafter, in further 30 untreated celiac patients we employed three newly characterized anti-tTG monoclonal antibodies produced against recombinant human-tTG. The epitopes recognized are located in three distinct domains of the protein corresponding to the core, C1 and C2 protein structure. Eleven age- and sex-matched patients with chronic duodenitis acted as controls. All subjects underwent upper endoscopy to obtain biopsy samples from the duodenum. Overall, we found that (i) tTG is equally expressed in CD at different stages of disease; (ii) tTG is expressed, at similar level, in CD and controls with duodenitis. Assessment of tTG level in biopsy samples by immunohistochemical methods is not useful in the clinical diagnostic work-up of CD.

Is human hepatocellular carcinoma a hormone-responsive tumor?

Before the positive results recently obtained with multitarget tyrosine kinase inhibitor sorafenib, there was no standard systemic treatment for patients with advanced hepatocellular carcinoma (HCC). Sex hormones receptors are expressed in a significant proportion of HCC samples. Following preclinical and epidemiological studies supporting a relationship between sex hormones and HCC tumorigenesis, several randomized controlled trials (RCTs) tested the efficacy of the anti-estrogen tamoxifen as systemic treatment. Largest among these trials showed no survival advantage from the administration of tamoxifen, and the recent Cochrane systematic review produced a completely negative result. This questions the relevance of estrogen receptor-mediated pathways in HCC. However, a possible explanation for these disappointing results is the lack of proper patients selection according to sex hormones receptors expression, but unfortunately the interaction between this expression and efficacy of tamoxifen has not been studied adequately. It has been also proposed that negative results might be explained if tamoxifen acts in HCC via an estrogen receptor-independent pathway, that requires higher doses than those usually administered, but an Asian RCT conducted to assess dose-response effect was completely negative. Interesting, preliminary results have been obtained when hormonal treatment (tamoxifen or megestrol) has been selected according to the presence of wild-type or variant estrogen receptors respectively, but no large RCTs are available to support this strategy. Negative results have been obtained also with anti-androgen therapy. In conclusion, there is no robust evidence to consider HCC a hormone-responsive tumor. Hormonal treatments should not be part of the current management of HCC.

Gastrointestinal bleeding in the elderly

Gastrointestinal bleeding affects a substantial number of elderly people and is a frequent indication for hospitalization. Bleeding can originate from either the upper or lower gastrointestinal tract, and patients with gastrointestinal bleeding present with a range of symptoms. In the elderly, the nature, severity, and outcome of bleeding are influenced by the presence of medical comorbidities and the use of antiplatelet medication. This Review discusses trends in the epidemiology and outcome of gastrointestinal bleeding in elderly patients. Specific causes of upper and lower gastrointestinal bleeding are discussed, and recommendations for approaches to endoscopic diagnosis and therapy are given.

The NKG2D receptor: sensing stressed cells

The activating killer cell lectin-like receptor NKG2D plays a key role in the natural killer (NK) cell-mediated lysis of tumours and infected cells. Unlike other receptors, the ligands recognised by NKG2D are 'induced-self' ligands on stressed cells. This system requires precise regulation because inappropriate expression of NKG2D ligands might compromise NK cell activation. For therapeutic purposes it is essential to understand the mechanisms that regulate the expression and function of the NKG2D system. This review focuses on the importance of the signalling pathways involved in the regulation of the NKG2D receptor and its ligand expression in arming the immune response against infected or tumour cells and for the identification of new molecular targets and therapeutic strategies.

Endoscopic ulcer rates in healthy subjects associated with use of aspirin (81 mg q.d.) alone or coadministered with celecoxib or naproxen: a randomized, 1-week trial

AIM

To determine the rate of endoscopic gastric/duodenal ulcers (GDUs) associated with use of aspirin (81 mg q.d.) alone or coadministered with celecoxib or naproxen.

METHODS

In this multicenter, double-blind study, healthy subjects were randomized to receive daily aspirin (81 mg q.d.) plus celecoxib 200 mg q.d., naproxen 500 mg b.i.d., or placebo. Upper endoscopy was performed at baseline and day 7. The primary end point was incidence of GDUs >or=3 mm diameter.

RESULTS

Incidence of GDUs was significantly lower in subjects receiving celecoxib plus aspirin (7%) compared with naproxen plus aspirin (25.3%; relative risk [RR], 0.28 [95% confidence interval (CI), 0.17-0.45]; P < 0.001), but significantly higher than placebo plus aspirin (1.6%; RR, 4.78 [95% CI, 1.12-20.32]; P = 0.016).

CONCLUSION

In a healthy population taking aspirin (81 mg q.d.), coadministration of celecoxib resulted in fewer GDUs than naproxen, but significantly more mucosal damage than aspirin alone.

Transglutaminase treatment of wheat and maize prolamins of bread increases the serum IgA reactivity of celiac disease patients

Celiac disease (CD) is mediated by IgA antibodies to wheat gliadins and tissue transglutaminase (tTG). As tTG is homologous to microbial transglutaminase (mTG) used to improve foodstuff quality, it could elicit the immune response of celiac patients. This study evaluated the reactivity of IgA of celiac patients to prolamins of wheat and gluten-free (maize and rice flours) breads mTG-treated or not. Prolamins extracted from wheat and gluten-free breads were analyzed by ELISA and immunodetected on membranes with individual or pooled sera from nine celiac patients recently diagnosed. Sera pool IgA titers were higher against prolamins of mTG-treated wheat or gluten-free breads than against mTG-untreated, mainly due to two individual patients' sera. The electrophoretic pattern of gluten-free bread prolamins was changed by the mTG treatment, and a new 31000 band originated in maize was recognized by three CD patients' IgA.

What do we know about communicating risk? A brief review and suggestion for contextualising serious, but rare, risk, and the example of cox-2 selective and non-selective NSAIDs

BACKGROUND

Communicating risk is difficult. Although different methods have been proposed - using numbers, words, pictures or combinations - none has been extensively tested. We used electronic and bibliographic searches to review evidence concerning risk perception and presentation. People tend to underestimate common risk and overestimate rare risk; they respond to risks primarily on the basis of emotion rather than facts, seem to be risk averse when faced with medical interventions, and want information on even the rarest of adverse events.

METHODS

We identified observational studies (primarily in the form of meta-analyses) with information on individual non-steroidal anti-inflammatory drug (NSAID) or selective cyclooxygenase-2 inhibitor (coxib) use and relative risk of gastrointestinal bleed or cardiovascular event, the background rate of events in the absence of NSAID or coxib, and the likelihood of death from an event. Using this information we present the outcome of additional risk of death from gastrointestinal bleed and cardiovascular event for individual NSAIDs and coxibs alongside information about death from other causes in a series of perspective scales.

RESULTS

The literature on communicating risk to patients is limited. There are problems with literacy, numeracy and the human tendency to overestimate rare risk and underestimate common risk. There is inconsistency in how people translate between numbers and words. We present a method of communicating information about serious risks using the common outcome of death, using pictures, numbers and words, and contextualising the information. The use of this method for gastrointestinal and cardiovascular harm with NSAIDs and coxibs shows differences between individual NSAIDs and coxibs.

CONCLUSION

Although contextualised risk information can be provided on two possible adverse events, many other possible adverse events with potential serious consequences were omitted. Patients and professionals want much information about risks of medical interventions but we do not know how best to meet expectations. The impact of contextualised information remains to be tested.

Effectiveness of national provider prescription of PPI gastroprotection among elderly NSAID users

OBJECTIVES

Our aim was to quantify the effect of provider adherence on the risk of NSAID-related upper gastrointestinal events (UGIE).

METHODS

We identified from national pharmacy records veterans > or = 65 yr prescribed an NSAID, a coxib, or salicylate (>325 mg/day) at any Veterans Affairs (VA) facility (January 1, 2000 to December 31, 2002). Prescription fill data were linked in longitudinal fashion to VA inpatient, outpatient, and death files and merged with demographic, inpatient, outpatient, and provider data from Medicare. Each person-day of follow-up was assessed for exposure to NSAID alone, NSAID+proton pump inhibitor (PPI), coxib, or coxib+PPI. UGIE was defined using our published, validated algorithm. Unadjusted incidence density ratios were calculated for the 365 days following exposure. We assessed risk of UGIE using Cox proportional hazards models, while adjusting for demographics, UGIE risk factors, comorbidity, prescription channeling (i.e., propensity score), geographic location, and multiple time-dependent pharmacological covariates, including aspirin, steroids, anticoagulants, antiplatelets, statins, and selective serotonin reuptake inhibitors.

RESULTS

In our cohort of 481,980 (97.8% male, 85.3% white, mean age 73.9, standard deviation 5.6), a safer strategy was prescribed for 19.8%, and 2,753 UGIE occurred in 220,662 person-years of follow-up. When adjusted for prescription channeling, confounders, and effect modification-associated PPI, risk of UGIE was 1.8 (95% confidence interval [CI] 1.6-2.0) on NSAID alone, 1.8 (95% CI 1.5-2.0) on coxib alone, 1.1 (95% CI 0.7-4.6) on NSAID+PPI, and 1.1 (0.6-5.2) on coxib+PPI. When the analysis was adjusted for cumulative percent time spent on a PPI, risk of UGIE decreased from HR 3.0 (95% CI 2.6-3.7) when a PPI was prescribed 0-20% of the time to 1.1 (95% CI 1.0-1.3) when a PPI was prescribed 80-100% of the time.

CONCLUSIONS

Provider adherence to safer NSAID prescribing strategies is associated with fewer UGIE among the elderly. An adherent strategy lowers, but does not eliminate, risk of an NSAID-related UGIE.

Tolerability and safety of mercaptopurine in azathioprine-intolerant patients with inflammatory bowel disease

BACKGROUND

Azathioprine intolerance is a common clinical problem, requiring drug withdrawal in up to 30% of patients. The successful use of mercaptopurine is described, but data to support this strategy are needed.

AIMS

To assess the tolerability of mercaptopurine in inflammatory bowel disease patients previously intolerant of azathioprine, and identify predictive factors.

METHODS

Sixty-one azathioprine-intolerant patients (31 males, median age at diagnosis 32 years, 31 with Crohn's disease, 30 with ulcerative colitis) who had been treated with mercaptopurine were identified. Intolerances included nausea and vomiting, flu-like illness, neutropenia, hepatotoxicity and pancreatitis.

RESULTS

Mercaptopurine was tolerated by 59% (36 of 61) of azathioprine-intolerant patients (median dose 1.0 mg/kg), 61% (17 of 28) in patients with azathioprine-related nausea and vomiting, 61% (11 of 18) with flu-like illness, 33% (three of nine) with hepatotoxicity, 100% (one of one) with neutropenia, 100% (three of three) with rash and 0% (zero of one) with pancreatitis. Mercaptopurine intolerance was frequently for a different adverse event. Those intolerant of mercaptopurine were younger (28.4 years vs. 37.0 years; P = 0.014) and more frequently female (14/30 vs. 2/29, P = 0.027). Mercaptopurine tolerability was not affected by diagnosis, location, behaviour, surgery, smoking, family history or extra-intestinal manifestations.

CONCLUSION

Mercaptopurine may be tolerated in up to 60% of azathioprine-intolerant patients, and treatment should be considered, particularly if intolerance was due to nausea, vomiting, flu-like illness or rash.

Proton-pump inhibitors are associated with a reduced risk for bleeding and perforated gastroduodenal ulcers attributable to non-steroidal anti-inflammatory drugs: a nested case-control study

Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) is hampered by gastrointestinal ulcer complications, such as ulcer bleeding and perforation. The efficacy of proton-pump inhibitors in the primary prevention of ulcer complications arising from the use of NSAIDs remains unproven. Selective cyclooxygenase-2 (COX-2) inhibitors reduce the risk for ulcer complications, but not completely in high-risk patients. This study determines which patients are especially at risk for NSAID ulcer complications and investigates the effectiveness of different preventive strategies in daily clinical practice. With the use of a nested case-control design, a large cohort of NSAID users was followed for 26 months. Cases were patients with NSAID ulcer complications necessitating hospitalisation; matched controls were selected from the remaining cohort of NSAID users who did not have NSAID ulcer complications. During the observational period, 104 incident cases were identified from a cohort of 51,903 NSAID users with 10,402 patient years of NSAID exposure (incidence 1% per year of NSAID use, age at diagnosis 70.4 ± 16.7 years (mean ± SD), 55.8% women), and 284 matched controls. Cases were characterised by serious, especially cardiovascular, co-morbidity. In-hospital mortality associated with NSAID ulcer complications was 10.6% (incidence 21.2 per 100,000 NSAID users). Concomitant proton-pump inhibitors (but not selective COX-2 inhibitors) were associated with a reduced risk for NSAID ulcer complications (the adjusted odds ratio 0.33; 95% confidence interval 0.17 to 0.67; p = 0.002). Especially at risk for NSAID ulcer complications are elderly patients with cardiovascular co-morbidity. Proton-pump inhibitors are associated with a reduced risk for NSAID ulcer complications.

The problem with NSAIDs: what data to believe?

Patients with rheumatoid arthritis and osteoarthritis have relied upon NSAIDs as a cornerstone of their analgesic regime for decades. The choice of anti-inflammatory agents broadened for this group of patients when the selective inhibitors of cyclooxygenase-2 enzyme were developed. Much has been published in the past few years regarding the superior gastrointestinal safety of this class of drugs when compared with traditional NSAIDs. Their triumphant debut was swiftly followed by the emergence of data detailing their associated increased serious cardiovascular risks. This also led to a reevaluation of data concerning more traditional NSAIDs, and surprisingly, a similar trend was seen. The US Food and Drug Administration has recommended that both classes of drugs carry a black box warning with regard to gastrointestinal and cardiovascular risks.

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.

Bleeding peptic ulcer in the elderly: risk factors and prevention strategies

Peptic ulcer bleeding is a frequent and dramatic event with both a high mortality rate and a substantial cost for healthcare systems worldwide. It has been found that age is an independent predisposing factor for gastrointestinal bleeding, with the risk increasing significantly in individuals aged>65 years and increasing further in those aged>75 years. Indeed, bleeding incidence and mortality are distinctly higher in elderly patients, especially in those with co-morbidities. NSAID therapy and Helicobacter pylori infection are the most prevalent aetiopathogenetic factors involved in peptic ulcer bleeding. The risk of bleeding seems to be higher for NSAID- than for H. pylori-related ulcers, most likely because the antiplatelet action of NSAIDs impairs the clotting process. NSAID users may be classified as low or high risk, according to the absence or presence of one or more of the following factors associated with an increased risk of bleeding: co-morbidities; corticosteroid or anticoagulant co-therapy; previous dyspepsia, peptic ulcer or ulcer bleeding; and alcohol consumption. Different types of NSAIDs have been associated with different bleeding risk, but no anti-inflammatory drug, including selective cyclo-oxygenase (COX)-2 inhibitors, is completely safe for the stomach. Furthermore, even low-dose aspirin (acetylsalicylic acid) [<325 mg/day] and a standard dose of non-aspirin antiplatelet treatment (clopidogrel or ticlopidine) have been found to cause bleeding and mortality. No clear risk factor favouring H. pylori-related ulcer bleeding has been identified. Peptic ulcer bleeding prevention remains a challenge for the physician, but data are now available on use of a safer and cheaper strategy for both low- and high-risk patients. Unfortunately, despite the fact that several society and national guidelines have been formulated, these are poorly followed in clinical practice. Proton pump inhibitor (PPI) or misoprostol therapy and H. pylori eradication in NSAID-naive patients are the most commonly proposed strategies. Selective COX-2 inhibitor therapy in high-risk patients has also been suggested, but concerns over the possible cardiovascular adverse effects of some of these agents should be taken into account. Moreover, switching to selective COX-2 inhibitors in patients with previous bleeding is not completely risk free, and concomitant PPI therapy is also needed. H. pylori eradication is mandatory in all patients with peptic ulcer, and such an approach has been found to be significantly superior to PPI maintenance therapy. H. pylori eradication is frequently achieved with sequential therapy in elderly patients with peptic ulcer. In conclusion, upper gastrointestinal bleeding is a dramatic event with a high mortality rate, particularly in the elderly. Some effective preventative strategies are now available that should be implemented in clinical practice.

The David Y. Graham lecture: use of nonsteroidal antiinflammatory drugs in a COX-2 restricted environment

Recent evidence suggests that both cyclooxygenase-2 (COX-2) inhibitors and nonselective NSAIDs, with the possible exception of naproxen, increase cardiovascular (CV) hazard. Clinicians should assess not only patients' GI risk but also their CV risk before prescribing these drugs. Patients with low CV risk can be managed according to their GI risk-low-risk patients (without risk factors) receive nonselective NSAIDs, medium risk patients (1-2 risk factors) receive COX-2 inhibitors or nonselective NSAIDs plus a proton pump inhibitor (PPI) or misoprostol, whereas high-risk patients (multiple risk factors, previous ulcer complications, or concomitant anticoagulants) receive a COX-2 inhibitor plus a PPI or misoprostol. Among patients with high CV risk (e.g., prior cardiothrombotic events) who require NSAIDs, naproxen is preferred. These patients should receive a prophylactic PPI or misoprostol because the risk of ulcer bleeding is substantially increased with concomitant use of naproxen and low-dose aspirin. Substitution of clopidogrel for aspirin is not recommended in patients at risk for upper GI bleeding who require antiplatelet therapy. Patients with high GI and high CV risk should avoid NSAIDs and COX-2 inhibitors. If antiinflammatory analgesics are required, the choice of therapy depends on the relative importance of GI and CV risks of individual patients. Combination of naproxen, low-dose aspirin, and a PPI or misoprostol is recommended if CV risk is the major concern (e.g., recent myocardial infarction). In contrast, combination of low-dose COX-2 inhibitor, low-dose aspirin, and a PPI or misoprostol is preferred if GI risk outweighs CV risk (e.g., recent ulcer bleeding and stable CV disease).

Meta-analysis: gastrointestinal bleeding due to interaction between selective serotonin uptake inhibitors and non-steroidal anti-inflammatory drugs

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) have been associated with upper gastrointestinal haemorrhage (UGIH) but the magnitude and characteristics of this reaction and possible interaction with concurrent Non-Steroidal Anti-Inflammatory Drug (NSAID) therapy are unknown.

AIM

To evaluate systematically the risk of UGIH with SSRIs, including interaction with NSAIDs.

METHODS

We searched PubMED, Science Citation Index, and trial registries for data on SSRIs, NSAIDs and UGIH. We evaluated spontaneous case reports from pharmacovigilance databases.

RESULTS

Random effects meta-analysis of four observational studies involving 153 000 patients showed an odds ratio of 2.36 (95% CI: 1.44-3.85; P = 0.0006) for SSRI associated UGIH. The odds ratio increased to 6.33 (95% CI: 3.40-11.8; P < 0.00001) with concomitant NSAIDs. In patients aged above 50 years with no UGIH risk factors, the Number-Needed-to-Harm per year is 411 for SSRIs alone, and 106 with concomitant NSAIDs. Analysis of 101 spontaneous reports showed that UGIH occurred after a median of 25 weeks with SSRIs. Around 67% of these patients were on NSAIDs.

CONCLUSIONS

Selective serotonin reuptake inhibitor use, alone and in combination with NSAIDs, substantially increases the risk of UGIH. Clinicians should consider this when managing patients at risk of, or presenting with UGIH.

Are COX-2 inhibitors preferable to non-selective non-steroidal anti-inflammatory drugs in patients with risk of cardiovascular events taking low-dose aspirin?

Cyclo-oxygenase-2 selective inhibitors and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) are associated with increased risk of acute cardiovascular events. Only aspirin offers primary and secondary cardiovascular prophylaxis, but trials have not answered directly whether low-dose aspirin is cardioprotective with COX-2 inhibitors. A large inception cohort study showed that concomitant use of aspirin reduced risk of cardiovascular events when given with rofecoxib, celecoxib, sulindac, meloxicam, and indometacin but not when given with ibuprofen. In large trials assessing gastrointestinal safety, there were fewer gastrointestinal events in patients using both COX-2 inhibitors and aspirin than in those using non-selective NSAIDs and aspirin; significantly fewer uncomplicated upper gastrointestinal events took place in the MEDAL trial. Analysis of VIGOR and two capsule endoscopy studies showed significantly less distal gastrointestinal blood loss with COX-2 inhibitors than with non-selective NSAIDs. Endoscopy trials showed that low-dose aspirin does not diminish the gastrointestinal benefits of COX-2 inibitors over non-selective NSAIDs. In an elderly epidemiological cohort receiving aspirin, both celecoxib and rofecoxib reduced risk of admission for gastrointestinal events. Comparison of the cardiovascular and gastrointestinal risks is difficult: likelihood and severity of cardiovascular events differ between individuals, agents, and exposure. Mortality associated with gastrointestinal events is less frequent than with cardiovascular events, but asymptomatic ulcers can result in severe complications. Data support the conclusion that COX-2 inhibitors are preferable to non-selective NSAIDs in patients with chronic pain and cardiovascular risk needing low-dose aspirin, but relative risks and benefits should be assessed individually for each patient.

Idiosyncratic drug-induced liver injury: an overview

Drug-induced liver injury (DILI) encompasses a spectrum of clinical disease ranging from mild biochemical abnormalities to acute liver failure. The majority of adverse liver reactions are idiosyncratic, occurring in most instances 5-90 days after the causative medication was last taken. The diagnosis of DILI is clinical, based on history, probability of the suspect medication as a cause of liver injury and exclusion of other hepatic disease. DILI can be hepatocellular (predominant rise in alanine transaminase), cholestatic (predominant rise in alkaline phosphatase) or mixed liver injury. An elevated bilirubin level more than twice the upper limit of normal in patients with hepatocellular liver injury implies severe DILI, with a mortality of approximately 10% and with an incidence rate of 0.7-1.3 per 100,000. Although acute liver failure is rare, 13-17% of all acute liver failure cases are attributed to idiosyncratic drug reactions. Response to drug withdrawal may be delayed up to 1 year with cholestatic liver injury with occasional subsequent progressive cholestasis known as the vanishing bile duct syndrome. Overall, chronic disease may occur in up to 6% even if the offending drug is withdrawn. Antibiotics and NSAIDs are the most common cause of DILI. Statins rarely cause significant liver injury whereas antiretroviral therapy is associated with hepatotoxicity in 10% of treated patients. Multiple mechanisms of DILI have been implicated, including TNF-alpha-activated apoptosis, inhibition of mitochondrial function and neoantigen formation. Risk factors for DILI include age, sex and genetic polymorphisms of drug-metabolising enzymes such as cytochrome P450. In patients with human immunodeficiency virus, the presence of chronic viral hepatitis increases the risk of antiretroviral therapy hepatotoxicity. Over the next decade, the combination of accurate case ascertainment of DILI via clinical networks and the application of genomics and proteomics will hopefully lead to accurate prediction of risk of DILI, so that pharmacotherapy can be optimised with avoidance of adverse hepatic events.

Analysis of the risk factors and their combinations in acute gastroduodenal ulcer bleeding: a case-control study

OBJECTIVE

Traditional non-steroidal anti-inflammatory drugs (NSAIDs) including ASA for thrombosis prophylaxis (ASA-TP), for pain medication (ASA-P) or non-ASA NSAIDs (NANSAIDs), Helicobacter pylori infection, CagA strains of H. pylori and smoking are reported risk factors for peptic ulcer bleeding (PUB), but the combined and the dose effects of these factors are controversial. The aim of this study was to estimate the significance of these risk factors and their combinations in PUB.

MATERIAL AND METHODS

PUB patients (n = 94) were compared with an age- (+/- 5 years) and gender-matched control group of non-ulcer patients (n = 94) attending elective endoscopy. A questionnaire on the possible risk factors (previous gastric and duodenal ulcer, use of ASA-TP, ASA-P, NANSAIDs, warfarin, alcohol and smoking) was completed. H. pylori infection was determined as positive if histology and/or urease tests were positive. CagA antibodies of IgG class were determined using an immunoblot method.

RESULTS

H. pylori infection (odds ratio (OR) 8.8), the use of ASA-P (OR 3.5), ASA-TP (OR 4.07), NANSAIDs with > or =1 defined daily dose (OR 6.56), smoking > or =20 cigarettes daily (OR 6.43) and previous duodenal ulcer (DU) (OR 8.96) were independent risk factors for PUB. At least two risk factors were present in 65% of PUB patients. CagA strains were detected in 97% of the H. pylori-positive cases and in 96% of the respective controls. ASA, ibuprofen, ketoprofen and smoking were dose-dependent risk factors for PUB.

CONCLUSIONS

Previous DU, H. pylori, the use of any ASA and smoking explained the majority of the PUB episodes. CagA strains of H. pylori were not associated with PUB. Two-thirds of the PUB patients had at least two risk factors, but their combination did not potentiate the risk.

Elevated B cell-activating factor of the tumour necrosis factor family in coeliac disease

OBJECTIVE

The B cell-activating factor of the tumour necrosis factor (TNF) family (BAFF) was recently described as a critical survival factor for B cells, and its expression is increased in several autoimmune diseases. Abnormal production of BAFF disturbs immune tolerance allowing the survival of autoreactive B cells and participates in the progression of B-cell lymphomas. Coeliac disease (CD) is a common autoimmune disorder induced by gluten intake in genetically predisposed individuals, associated with autoantibody production and with an increased risk of lymphoma at follow-up. The purpose of this study was to investigate the possible implications of BAFF in CD.

MATERIAL AND METHODS

Seventy-three patients with small-bowel biopsies and laboratory-proven diagnosis of CD were included in the study. All serum samples were analysed before the start of a gluten-free diet (GFD). In 12 cases, one or more samples were analysed during follow-up of the GFD. Seventy-seven blood donors were taken as controls. Serum BAFF levels and anti-transglutaminase (a-tTG) antibodies were assessed by ELISA and endomysial antibodies by indirect immunofluorescence.

RESULTS

Serum BAFF levels appeared to be significantly more elevated in CD patients than in controls (p<0.0001) and, compared with other autoimmune diseases where BAFF is increased, a much larger percentage (80.8%) of CD patients presented BAFF levels above the normal range. In addition, serum BAFF levels were found to correlate with a-tTG antibody levels (p =0.0007) and there was a significant reduction of BAFF after introduction of a GFD.

CONCLUSIONS

BAFF may represent a possible pathogenic factor in CD. Its implications for the diagnosis, prognosis and treatment of CD should also be assessed.

Needles in haystacks

Drug-induced liver disease remains a significant problem for physicians caring for patients with this therapeutic complication and for those developing and licensing new drugs. There has been renewed interest recently in drug-induced liver injury (DILI) investigation, with respect to the assessment of causality to permit prompt and accurate diagnosis and the determination of risk factors and the mechanisms by which drugs injure the liver, both in a predictable dose-dependent manner and idiosyncratically. Current investigations focus on determining the true incidence of such adverse drug hepatotoxic reactions, both for drug development and clinical practice, as well as on elucidating the mechanisms of disease and on finding diagnostic biomarkers. The Drug Induced Liver Injury Network (DILIN), supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), includes in its charge the study of four drugs (phenytoin, isoniazid, amoxicillin/clavulanic acid, and valproic acid) that are relatively frequent causes of DILI. In the current study, the authors have attempted to search an institutional diagnostic database of the International Classification of Diseases-9th Edition-Clinical Modification (ICD-9-CM) codes, using three different strategies, to identify patients with DILI due to the four targeted drugs. Unfortunately, the search strategy that yielded the greatest number of specific DILI cases was too insensitive and labor-intensive to be useful for DILI research, whereas strategies that were more specific were also far less sensitive and yielded an inadequate number of cases to study. The findings in this report emphasize the inadequacy of administrative patient diagnosis databases for specific research in DILI and lend support to the DILIN concept that is funded by NIDDK as the most suitable means to further understanding in this burgeoning field.

Upper gastrointestinal bleeding and the changing use of COX-2 non-steroidal anti-inflammatory drugs and low-dose aspirin

BACKGROUND

Rofecoxib was withdrawn in 2004.

AIM

To assess the incidence of upper gastrointestinal bleeding in the context of the changing use of cyclo-oxygenase-2 non-steroidal anti-inflammatory drugs and low-dose aspirin.

METHODS

We examined the characteristics of patients developing upper gastrointestinal bleeding in a defined population in south-west Scotland. The primary comparisons were made between two calendar years, preceding and following the withdrawal of rofecoxib.

RESULTS

The overall incidence of upper gastrointestinal bleeding rose from 98.7 in 2002 to 143 per 10(5) of the population per annum in 2005 (chi(2) = 21.1; P < 0.001). The rise in the incidence was associated with using low-dose aspirin, from 26.6 to 38.4 per 10(5) (chi(2) = 5.4; P = 0.02), other antithrombotic drugs, from 12.1 to 30.2 per 10(5) (chi(2) = 19.6; P < 0.001), and excess alcohol, from 23.5 to 36.4 per 10(5) (chi(2) = 7.1; P = 0.008), but insignificantly with using non-steroidal anti-inflammatory drugs, from 13.3 to 16.1 per 10(5) (chi(2) = 0.64; P = 0.4). After adjustment for the concomitant use of these drugs, there was no significant trend in the incidence of upper gastrointestinal bleeding associated with non-steroidal anti-inflammatory drugs over the period of 1996-2005.

CONCLUSION

The rise in the incidence of upper gastrointestinal bleeding was weakly related to the change in use of non-steroidal anti-inflammatory drugs. Instead, it probably reflected the increasing use of low-dose aspirin, other antithrombotic drugs and alcohol.

Sequential evaluation of thiopurine methyltransferase, inosine triphosphate pyrophosphatase, and HPRT1 genes polymorphisms to explain thiopurines' toxicity and efficacy

AIM

To evaluate the polymorphisms of several genes involved in the azathioprine and mercaptopurine metabolism, in an attempt to explain their toxicity and efficacy in Crohn's disease and ulcerative colitis.

METHODS

In 422 consecutive patients (250 with Crohn's disease and 172 with ulcerative colitis) and 245 healthy controls, single nucleotide polymorphisms of thiopurine methyltransferase, inosine triphosphate pyrophosphatase and hypoxanthine phosphoribosyl transferase (HPRT1) genes were related to the occurrence of adverse drug reactions (ADRs) and efficacy of therapy.

RESULTS

Seventy-three patients reported 81 episodes of ADRs; 45 patients did not respond to therapy. Frequency of thiopurine methyltransferase risk haplotypes was significantly increased in patients with leucopenia (26% vs. 5.7% in patients without ADRs, and 4% of controls) (P < 0.001); no correlation with other ADRs and efficacy of therapy was found. Conversely, the frequency of inosine triphosphate pyrophosphatase and HPRT1 risk genotypes was not significantly different in patients with ADRs (included leucopenia). Non-responders had an increased frequency of inosine triphosphate pyrophosphatase risk genotypes (P = 0.03).

CONCLUSIONS

The majority of azathioprine/mercaptopurine-induced ADRs and efficacy of therapy are not explained by the investigated gene polymorphisms. The combined evaluation of all three genes enhanced the correlation with leucopenia (43.5% vs. 23% in controls) (P = 0.008), at the expense of a reduced accuracy (60%).

Principles of Antimicrobial Use in Older Adults

The fundamental principles of treating infectious diseases apply to elderly patients, but certain aspects of therapy such as the selection of empiric regimens and risk stratification for severe or atypical disease are influenced by comorbidities, lifestyle, and immunosenescence. Knowledge of age-related changes in pharmacokinetic parameters and potential drug-drug interactions assists the clinician in determining appropriate dosing and monitoring parameters. Based on current evidence, the recommended approach includes careful selection and aggressive dosing of initial broad-spectrum antimicrobials followed by de-escalation to appropriate agents to maximize clinical outcomes and minimize toxicity and adverse effects. Greater enrollment of the elderly in therapeutic studies is needed to detect differences in the efficacy and safety of antimicrobials.

Causality assessment of drug-induced hepatotoxicity: promises and pitfalls

Drug-induced liver injury is the leading cause of acute liver failure in the United States, but the ability to ascribe hepatic injury confidently to a specific drug remains a challenging and often difficult pursuit. This article explores the ongoing challenges inherent in what is currently a clinical process of elimination made in the attempt of assigning causality in drug-induced liver injury. In particular, it points out the shortcomings and pitfalls that often limit the applicability of the causality-assessment methodologies currently in use.

Long-term follow-up of patients with mild to moderate drug-induced liver injury

AIM

To evaluate the long-term prognosis of patients diagnosed with drug-induced liver injury, and the nature of the liver injury.

METHODS

Patients with a diagnosis of drug-induced liver injury between 1994 and 2005 were identified in a university hospital clinic. Patients surviving drug-induced liver injury-associated liver failure were excluded.

RESULTS

Seventy-seven cases were identified and those who were alive (69) were invited to attend follow-up. Of those patients who had died, none had died of liver disease. Of those patients who had survived, 59 were reviewed in the clinic. Patients had a median follow-up of 48 months. Before the diagnosis of drug-induced liver injury, nine had a chronic liver disease, four with autoimmune hepatitis, two with non-alcoholic liver disease, one each with non-alcoholic fatty liver disease, primary biliary cirrhosis and primary sclerosing cholangitis. There was no evidence of progression of their liver disease during follow-up. Among 50 patients without a known liver disease prior to the drug-induced liver injury, 10 had abnormal liver tests. Diagnostic work-up revealed alternative cause of liver disease in all except three patients (6%), who had asymptomatic abnormal liver tests (but normal bilirubin in all).

CONCLUSIONS

Chronic abnormalities in liver tests, not explained by an identified liver disease, are very rare in patients previously diagnosed with drug-induced liver injury. This group of patients did not seem to have a clinically significant liver injury at long-term follow-up.

Monitoring liver safety in drug development: the GSK experience

To promptly identify and evaluate liver safety events, an evidence-based liver safety system was created for global Phase I-III clinical trials. The goals of this system included improving clinical trial subject safety, expanding information on liver safety events, and improving data quality across studies by establishing and communicating: Two different algorithms for liver stopping criteria were developed. The most stringent criteria were selected for healthy volunteers in Phase I studies, where no treatment benefit is anticipated and clinical safety data are limited. With an interest in assessing potential liver "tolerance" or adaptation with accruing safety information, slightly higher liver chemistry thresholds were set for Phase II-III studies. This paper will describe the importance of liver safety in drug development, laboratory tests used to monitor liver safety, the rationale for selected liver chemistry subject stopping criteria, and implementation of this safety system.

COX-2 in play at the AHA and the FDA

The inhibition of cyclooxygenase (COX)-2 confers a small but absolute risk of cardiovascular events on patients taking nonsteroidal anti-inflammatory drugs (NSAIDs). This risk has been established by placebo-controlled trials of NSAIDs selective for COX-2; traditional NSAIDs seem to be heterogeneous with respect to cardiovascular risk. The American Heart Association (AHA) has proposed a 'stepped-care' approach to the use of NSAIDs in patients with cardiovascular disease, whereas the Food and Drug Administration (FDA) has failed to approve the COX-2-selective NSAID etoricoxib. In this article, these actions of the AHA and the FDA are interpreted in the light of current knowledge, prompting the formulation of scientific questions that might be addressed.

Inhibition of Human Thiopurine S-Methyltransferase by Various Nonsteroidal Anti-inflammatory Drugs in Vitro: A Mechanism for Possible Drug Interactions

Thiopurine S-methyltransferase (TPMT) is a biotransformation phase II enzyme responsible for the metabolic inactivation of thiopurine drugs. The present study was carried out to investigate the inhibitory potential of 15 nonsteroidal anti-inflammatory drugs (NSAIDs) on human TPMT activity in vitro. TPMT activity was measured in pooled human erythrocytes in the absence and presence of various NSAIDs using the previously published high-performance liquid chromatography-UV method. To determine the inhibition type and K(i) value for each compound, we performed kinetic analysis at five different inhibitor concentrations close to the IC(50) value obtained in preliminary experiments. Naproxen (K(i) = 52 microM), mefenamic acid (K(i) = 39 microM), and tolfenamic acid (K(i) = 50 microM) inhibited TPMT activity in a noncompetitive manner. The estimated K(i) values for the inhibition of TPMT by ketoprofen (K(i) = 172 microM) and ibuprofen (K(i) = 1043 microM) indicated that the propionic acid derivatives were relatively weak inhibitors of TPMT. Our results suggest that coadministration of thiopurines and various NSAIDs may lead to drug interactions.

Review article: drug hepatotoxicity

BACKGROUND

Drug toxicity is the leading cause of acute liver failure in the United States. Further understanding of hepatotoxicity is becoming increasingly important as more drugs come to market.

AIMS

(i) To provide an update on recent advances in our understanding of hepatotoxicity of select commonly used drug classes. (ii) To assess the safety of these medications in patients with pre-existing liver disease and in the post-liver transplant setting. (iii) To review relevant advances in toxicogenomics which contribute to the current understanding of hepatotoxic drugs.

METHODS

A Medline search was performed to identify relevant literature using search terms including 'drug toxicity, hepatotoxicity, statins, thiazolidinediones, antibiotics, antiretroviral drugs and toxicogenomics'.

RESULTS

Amoxicillin-clavulanic acid is one of the most frequently implicated causes of drug-induced liver injury worldwide. Statins rarely cause clinically significant liver injury, even in patients with underlying liver disease. Newer thiazolidinediones are not associated with the degree of liver toxicity observed with troglitazone. Careful monitoring for liver toxicity is warranted in patients who are taking antiretrovirals, especially patients who are co-infected with hepatitis B and C. Genetic polymorphisms among enzymes involved in drug metabolism and HLA types may account for some of the differences in individual susceptibility to drug hepatotoxicity.

CONCLUSIONS

Drug-induced hepatotoxicity will remain a problem that carries both clinical and regulatory significance as long as new drugs continue to enter the market. Future results from ongoing multicentre collaborative efforts may help contribute to our current understanding of hepatotoxicity associated with drugs.

Drug-induced liver disease in 2006

PURPOSE OF REVIEW

To identify the key publications of 2006 dealing with drug-induced liver injury.

RECENT FINDINGS

When given in therapeutic doses over 14 days, acetaminophen produced significant asymptomatic elevations in alanine aminotransferase among healthy volunteers, suggesting that subclinical injury may be more common than previously thought. Acute liver failure in children was shown to differ in several important respects from that seen in adults, notably a much lower incidence of acetaminophen toxicity with nearly half of all cases being indeterminate in origin. The first cases of hepatotoxicity with telithromycin, a new class of ketolide antibiotic, were described along with reports suggesting liver injury from ezetimibe among other agents. The potential for chronic injury to develop after acute drug-induced liver injury was analyzed in a large Swedish database; 5-6% of cases were judged to become chronic, with drugs causing cholestatic injury predominating. Among well described hepatotoxins, new reports appeared with highly active antiretroviral therapy agents, herbal therapies and several antibiotics. Finally, the safe use of pravastatin and pioglitazone was demonstrated in patients with chronic liver disease in controlled clinical trials.

SUMMARY

Drug-induced liver injury remains an important concern for many existing drugs as well as for agents in development.

Assessment of thiopurine methyltransferase enzyme activity is superior to genotype in predicting myelosuppression following azathioprine therapy in patients with inflammatory bowel disease

BACKGROUND

Myelosuppression occurs in 2-7% of inflammatory bowel disease (IBD) patients treated with azathioprine, and can be associated with reduced activity of thiopurine methyltransferase (TPMT) in some patients. It has been proposed that pretreatment assessment of TPMT status reduces the incidence of toxicity and is cost-effective.

AIMS

To determine if screening for TPMT status predicts side-effects to azathioprine in patients with IBD and to ascertain whether screening by TPMT enzyme activity or genotype is superior.

METHODS

Sequential IBD patients were identified and azathioprine tolerance recorded. Blood was collected for measurement of TPMT activity and TPMT*3C, TPMT*3A and TPMT*2 genotypes.

RESULTS

Of 130 patients, 25% stopped azathioprine because of toxicity. Four patients experienced severe myelosuppression (WCC < 2). Eleven of 17 patients with reduced TPMT activity were heterozygotes, including one patient with marked TPMT deficiency who experienced severe myelosuppression. There was no association between intermediate TPMT deficiency and any side-effect.

CONCLUSIONS

Moderate reduction of TPMT activity in heterozygotes was not associated with toxicity, but very low TPMT activity caused severe myelosuppression in one patient. This would have been predicted by measuring TPMT activity but not by genotyping. Measurement of TPMT activity may therefore be superior to genotype in predicting severe myelosuppression.

Adverse drug reactions related to amoxicillin alone and in association with clavulanic acid: data from spontaneous reporting in Italy

OBJECTIVES

To analyse an Italian database of spontaneous reporting of suspected adverse drug reactions in order to compare the safety profile of amoxicillin and amoxicillin/clavulanic acid.

METHODS

Data were retrieved from the spontaneous reports collected by six Italian regions (the GIF database) from January 1988 to June 2005. Drug utilization data were also available for the two drugs. The comparison between amoxicillin and amoxicillin/clavulanic acid was made using the chi(2) or Student's t-test, when appropriate. Disproportionality in reporting of adverse events was assessed using reporting odds ratio methodology.

RESULTS

Up to June 2005, the GIF database collected 37 906 reports, of which 1088 were related to amoxicillin/clavulanic acid and 1095 to amoxicillin. The percentage of skin reactions was statistically higher for amoxicillin (82%) than for amoxicillin/clavulanic acid (76%); on the contrary, the percentage of gastrointestinal, hepatic and haematological reactions was significantly higher for amoxicillin/clavulanic acid (13%, 4% and 2%, respectively) than for amoxicillin (7%, 1% and 1%, respectively). Amoxicillin/clavulanic acid seems to be associated with a higher risk of Stevens-Johnson syndrome, purpura and hepatitis than amoxicillin alone. In particular, the reporting rate of hepatitis is on average 9-fold higher for amoxicillin/clavulanic acid than for amoxicillin.

CONCLUSIONS

Analysis shows a different safety profile for the two selected drugs. The combination of amoxicillin/clavulanic acid has been increasingly used in Italy and now represents the most frequently antibiotic prescribed by Italian general practitioners. Given the documented level of inappropriate use of beta-lactams in Italy, these results should be taken into account by physicians before prescribing amoxicillin/clavulanic acid to patients.

Low-dose aspirin and upper gastrointestinal damage: epidemiology, prevention and treatment

BACKGROUND

Low-dose aspirin (75-325 mg/day) is widely used for the prevention of cardiovascular disease. However, due to its action on cyclo-oxygenase (COX), aspirin is associated with upper gastrointestinal (GI) side effects including ulcers and bleeding.

SCOPE

This was a comprehensive review of the literature available on the side effects associated with low-dose aspirin, together with the available treatment and prevention options, which was based on the authors' expertise in the field and a supplementary PubMed search limited to papers published in English during the last 10 years, up to November 2006.

FINDINGS

Although the risk of upper GI side effects is smaller with low-dose aspirin compared with non-selective, non-steroidal anti-inflammatory drugs (NSAIDs), it is nevertheless a substantial healthcare issue. Factors associated with an increased risk of upper GI complications during low-dose aspirin therapy include aspirin dose, history of ulcer or upper GI bleeding, age > 70 years, concomitant use of NSAIDs (including COX-2-selective NSAIDs), and Helicobacter pylori infection. Co-administration of a gastroprotective agent such as proton pump inhibitors (PPIs) may be useful for alleviating the upper GI side effects associated with use of low-dose aspirin. Eradication of H. pylori also appears to reduce the risk of these side effects, especially in those at high risk. The use of other antiplatelet agents such as clopidogrel does not seem to provide a safer alternative to low-dose aspirin in at-risk patients.

CONCLUSIONS

Prophylactic low-dose aspirin therapy is associated with an increased risk of developing upper GI side effects. Administration of a PPI seems the most effective therapy for the prevention and/or relief of such side effects in at-risk patients. H. pylori eradication therapy further reduces the risk of upper GI bleeding in these patients.

Effect of antisecretory drugs and nitrates on the risk of ulcer bleeding associated with nonsteroidal anti-inflammatory drugs, antiplatelet agents, and anticoagulants

OBJECTIVES

After the withdrawal of some cyclooxygenase-2 (COX-2) selective inhibitors, traditional nonsteroidal anti-inflammatory drug (NSAID) use has increased, but without additional prevention strategies against upper gastrointestinal (GI) complications in many cases. Here, we report the effect of antisecretory drugs and nitrates on the risk of upper GI peptic ulcer bleeding (UGIB) associated with nonselective NSAIDs, aspirin, antiplatelet agents, and anticoagulants.

METHODS

This case-control study matched 2,777 consecutive patients with UGIB (confirmed by endoscopy) with 5,532 controls (2:1). Adjusted relative risks (RR) of UGIB are reported.

RESULTS

Proton pump inhibitors (PPIs) (RR 0.33, 95% confidence interval [CI] 0.27-0.39), H2-receptor antagonists (H2-RAs) (RR 0.65, 95% CI 0.50-0.85), and nitrates (RR 0.52, 95% CI 0.38-0.70) reduced UGIB risk. PPI use was associated with greater reductions among both traditional NSAID (RR 0.13, 95% CI 0.09-0.19 vs RR 0.30, 95% CI 0.17-0.53 with H2-RAs; RR 0.48, 95% CI 0.19-1.24 with nitrates) and low-dose aspirin users (RR 0.32, 95% CI 0.22-0.51 vs RR 0.40, 95% CI 0.19-0.73 with H2-RA; RR 0.69, 95% CI 0.36-1.04 with nitrates), and among patients taking clopidogrel (RR 0.19, 95% CI 0.07-0.49). For patients taking anticoagulants, use of nitrates, H2-RA, or PPIs was not associated with a significant effect on UGIB risk.

CONCLUSION

Antisecretory agent or nitrate treatment is associated with reduced UGIB RR in patients taking NSAID or aspirin. Only PPI therapy was associated with a marked, consistent risk reduction among patients receiving all types of agents (including nonaspirin antiplatelet agents). Protection was not apparent in patients taking anticoagulants.

Nutrigenetics and nutraceuticals: the next wave riding on personalized medicine

The Human Genome Project and subsequent identification of single nucleotide polymorphisms (SNPs) within populations has played a major role in predicting individual response to drugs (pharmacogenetics) leading to the concept of "personalized medicine." Nutritional genomics is a recent off-shoot of this genetic revolution that includes (1) nutrigenomics: the study of interaction of dietary components with the genome and the resulting proteonomic and metabolomic changes; and (2) nutrigenetics: understanding the gene-based differences in response to dietary components and developing nutraceuticals that are most compatible with health based on individual genetic makeup. Despite the extensive data on genetic polymorphisms in humans, its translation into medical practice has been slow because of the time required to accumulate population data on SNP incidence, understand the significance of a given SNP in disease, and develop suitable diagnostic tests. Nutrigenomics revitalized the field by showing that nutrients and botanicals can interact with the genome and modify subsequent gene expression, which has provided a great impetus for nutrigenetic research and nutraceutical development based on nutrigenetics. Polymorphisms in methlyene tetrahydrofolate reductase (MTHFR) (involved in folate metabolism), apolipoprotein E (Apo E) and ApoA1 (in cardiovascular disease), and leptin/leptin receptor (obesity) genes are some good examples for understanding basic nutrigenetics. Developing nutraceuticals to prevent and manage thrombosis risk in women with thrombophilic gene mutations are discussed in the context of the opportunities that exist at the nutrigenetic/pharmacogenetic interphase leading to "personalized nutrition." Further research on individual differences in genetic profiles and nutrient requirements will help establish nutrigenetics as an essential discipline for nutrition and dietetics practice.

Perioperative acute upper gastrointestinal haemorrhage in older patients with hip fracture: incidence, risk factors and prevention

BACKGROUND

No specific preventive strategy exists for acute gastrointestinal haemorrhage in hip fracture patients.

AIMS

To determine the effectiveness of prophylactic use of proton pump inhibitors in patients with risk factors for acute gastrointestinal haemorrhage.

METHODS

Prospective two-stage study of 822 consecutive older (> or =60 years) hip fracture patients.

RESULTS

Acute gastrointestinal haemorrhage occurred in 16 (3.9%) of 407 patients and was associated with increased length of hospital stay (28.7 vs. 15.9; P = 0.0027) and mortality (18.8% vs. 4.3%; P = 0.043). Multiple analysis identified five independent risk factors for acute gastrointestinal haemorrhage: pre-existing peptic ulcer (OR 4.3; P = 0.043), current smoking (OR 3.1; P = 0.023), post-operative use of an antiplatelet agent (OR 6.5; P = 0.046), post-operative use of non-steroidal anti-inflammatory drug/cyclo-oxygenase-2 inhibitor (OR 4.9; P = 0.06) and blood group O (OR 1.7; P = 0.046). These risk factors were highly sensitive and had a negative predictive value of 99.8%. Prophylactic use of proton pump inhibitors in patients with risk factor for acute gastrointestinal haemorrhage significantly reduced the incidence of this complication (0.72% in treated patients vs. 13.4% in untreated; P < 0.001); the number needed to treat was 7.9. Conclusions In older hip fracture patients perioperative acute gastrointestinal haemorrhage occurs in 3.9% and is associated with poor outcome. Preventive proton pump inhibitor therapy in patients at risk of acute gastrointestinal haemorrhage is effective and safe.

Risk of upper gastrointestinal complications among users of traditional NSAIDs and COXIBs in the general population

BACKGROUND & AIMS

Traditional nonaspirin, nonsteroidal anti-inflammatory drugs (tNSAIDs) have been associated with a 3- to 5-fold increased risk in upper gastrointestinal complications (UGIC). Whether use of selective inhibitors of cyclooxygenase-2 (COXIBs) will translate into a clinically relevant reduced toxicity has not been widely investigated in the general population.

METHODS

We conducted a nested case control study using The Health Improvement Network Database identifying 1561 cases of UGIC between January 2000 and 2005. A random sample of 10,000 controls was frequency matched to the cases by age, sex, and calendar year.

RESULTS

The adjusted relative risk (RR) of UGIC associated with current use was 3.7 (95% CI: 3.1-4.3) for tNSAIDs and 2.6 (95% CI: 1.9-3.6) for COXIBs. Daily dose was a predictor of increased risk for both tNSAIDs and COXIBs. Users of tNSAIDs with a prolonged plasma half-life or slow release formulations had an augmented risk of UGIC. Overall, the estimate of RR associated with COXIBs was 0.8 (95% CI: 0.6-1.1) compared with current use of tNSAIDs, and, among nonusers of aspirin, the corresponding estimate of RR associated with COXIBs was 0.6 (95% CI: 0.4-0.9).

CONCLUSIONS

COXIBs present a better upper gastrointestinal safety than tNSAIDs, although the risk of UGIC for an individual drug is determined by its daily dose and plasma drug exposure in addition to its selectivity for cyclooxygenase-2. Also, concomitant use of aspirin is a strong effect modifier of COXIBs that negates the superior gastrointestinal safety over tNSAIDs in the absence of aspirin use.

Assessment of drug-induced hepatotoxicity in clinical practice: a challenge for gastroenterologists

Currently, pharmaceutical preparations are serious contributors to liver disease; hepatotoxicity ranking as the most frequent cause for acute liver failure and post-commercialization regulatory decisions. The diagnosis of hepatotoxicity remains a difficult task because of the lack of reliable markers for use in general clinical practice. To incriminate any given drug in an episode of liver dysfunction is a step-by-step process that requires a high degree of suspicion, compatible chronology, awareness of the drug's hepatotoxic potential, the exclusion of alternative causes of liver damage and the ability to detect the presence of subtle data that favors a toxic etiology. This process is time-consuming and the final result is frequently inaccurate. Diagnostic algorithms may add consistency to the diagnostic process by translating the suspicion into a quantitative score. Such scales are useful since they provide a framework that emphasizes the features that merit attention in cases of suspected hepatic adverse reaction as well. Current efforts in collecting bona fide cases of drug-induced hepatotoxicity will make refinements of existing scales feasible. It is now relatively easy to accommodate relevant data within the scoring system and to delete low-impact items. Efforts should also be directed toward the development of an abridged instrument for use in evaluating suspected drug-induced hepatotoxicity at the very beginning of the diagnosis and treatment process when clinical decisions need to be made. The instrument chosen would enable a confident diagnosis to be made on admission of the patient and treatment to be fine-tuned as further information is collected.

Celiac disease

Celiac disease (CD) is a common autoimmune disorder, induced by the intake of gluten proteins present in wheat, barley and rye. Contrary to common belief, this disorder is a protean systemic disease, rather than merely a pure digestive alteration. CD is closely associated with genes that code HLA-II antigens, mainly of DQ2 and DQ8 classes. Previously, it was considered to be a rare childhood disorder, but is actually considered a frequent condition, present at any age, which may have multiple complications. Tissue transglutaminase-2 (tTG), appears to be an important component of this disease, both, in its pathogenesis and diagnosis. Active CD is characterized by intestinal and/or extra-intestinal symptoms, villous atrophy and crypt hyperplasia, and strongly positive tTG auto-antibodies. The duodenal biopsy is considered to be the "gold standard" for diagnosis, but its practice has significant limitations in its interpretation, especially in adults. Occasionally, it results in a false-negative because of patchy mucosal changes and the presence of mucosal villous atrophy is often more severe in the proximal jejunum, usually not reached by endoscopic biopsies. CD is associated with increased rates of several diseases, such as iron deficiency anemia, osteoporosis, dermatitis herpetiformis, several neurologic and endocrine diseases, persistent chronic hypertransami-nasemia of unknown origin, various types of cancer and other autoimmune disorders. Treatment of CD dictates a strict, life-long gluten-free diet, which results in remission for most individuals, although its effect on some associated extraintestinal manifestations remains to be established.