A review of gastric ulcer and gastroduodenal injury in normal volunteers receiving aspirin and other non-steroidal anti-inflammatory drugs

Identification of lignans as selective cyclooxygenase-2 inhibitors from the extract of Acanthopanacis cortex

Acanthopanacis cortex (the dried root bark of Acanthopanax gracilistylus W. W. Smith) has been used for the treatment of rheumatic diseases in China for over 2000 years. Four previously undescribed lignans (1-4) and 12 known lignans (5-16) were isolated from Acanthopanacis cortex. In this study, the inhibitory activities of compounds 1-16 against neutrophil elastase (NE), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) are reported. The results show that compounds 1-16 exhibit weak inhibitory activities against NE and COX-1. However, compounds 2, 6-8 and 13-16 demonstrate better COX-2 inhibitory effects with IC50 values from 0.75 to 8.17 μΜ. These findings provide useful information for the search for natural selective COX-2 inhibitors.

Lonicera japonica Thunb. Ethanol Extract Exerts a Protective Effect on Normal Human Gastric Epithelial Cells by Modulating the Activity of Tumor-Necrosis-Factor-α-Induced Inflammatory Cyclooxygenase 2/Prostaglandin E2 and Matrix Metalloproteinase 9

Gastric inflammation-related disorders are commonly observed digestive system illnesses characterized by the activation of proinflammatory cytokines, particularly tumor necrosis factor-α (TNF-α). This results in the induction of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PEG2) and matrix metallopeptidase-9 (MMP-9). These factors contribute to the pathogenesis of gastric inflammation disorders. We examined the preventive effects of Lonicera japonica Thunb. ethanol extract (Lj-EtOH) on gastric inflammation induced by TNF-α in normal human gastric mucosa epithelial cells (GES-1). The GES-1 cell line was used to establish a model that simulated the overexpression of COX-2/PGE2 and MMP-9 proteins induced by TNF-α to examine the anti-inflammatory properties of Lj extracts. The results indicated that Lj-EtOH exhibits significant inhibitory effects on COX-2/PEG2 and MMP-9 activity, attenuates cell migration, and provides protection against TNF-α-induced gastric inflammation. The protective effects of Lj-EtOH are associated with the modulation of COX-2/PEG2 and MMP-9 through the activation of TNFR-ERK 1/2 signaling pathways as well as the involvement of c-Fos and nuclear factor kappa B (NF-κB) signaling pathways. Based on our findings, Lj-EtOH exhibits a preventive effect on human gastric epithelial cells. Consequently, it may represent a novel treatment for the management of gastric inflammation.

Metabolic, toxicological, chemical, and commercial perspectives on esterification of dietary polyphenols: a review

Molecular modifications have been practiced for more than a century and nowadays they are widely applied in food, pharmaceutical, or other industries to manipulate the physicochemical, bioactivity, metabolic/catabolic, and pharmacokinetic properties. Among various structural modifications, the esterification/O-acylation has been well-established in altering lipophilicity and bioactivity of parent bioactive compounds, especially natural polyphenolics, while maintaining their high biocompatibility. Meanwhile, various classic chemical and enzymatic protocols and other recently emerged cell factory technology are being employed as viable esterification strategies. In this contribution, the main motivations of phenolic esterification, including the tendency to replace synthetic alkyl phenolics with safer alternatives in the food industry to improve the bioavailability of phenolics as dietary supplements/pharmaceuticals, are discussed. In addition, the toxicity, metabolism, and commercial application of synthetic and natural phenolics are briefly introduced. Under these contexts, the mechanisms and reaction features of several most prevalent chemical and enzymatic esterification pathways are demonstrated. In addition, insights into the studies of esterification modification of natural phenolic compounds and specific pros/cons of various reaction systems with regard to their practical application are provided.

Recent Advances in the Synthesis of Ibuprofen and Naproxen

Herein, we review the recent progress in the synthesis of representative nonsteroidal anti-inflammatory drugs (NSAIDs), ibuprofen and naproxen. Although these drugs were discovered over 50 years ago, novel practical and asymmetric approaches are still being developed for their synthesis. In addition, this endeavor has enabled access to more potent and selective derivatives from the key frameworks of ibuprofen and naproxen. The development of a synthetic route to ibuprofen and naproxen over the last 10 years is summarized, including developing methodologies, finding novel synthetic routes, and applying continuous-flow chemistry.

Acetylharpagide Protects Mice from Staphylococcus Aureus-Induced Acute Lung Injury by Inhibiting NF-κB Signaling Pathway

Staphylococcus aureus (S. aureus)-induced acute lung injury (ALI) is a serious disease that has a high risk of death among infants and teenagers. Acetylharpagide, a natural compound of Ajuga decumbens Thunb. (family Labiatae), has been found to have anti-tumor, anti-inflammatory and anti-viral effects. This study investigates the therapeutic effects of acetylharpagide on S. aureus-induced ALI in mice. Here, we found that acetylharpagide alleviated S. aureus-induced lung pathological morphology damage, protected the pulmonary blood-gas barrier and improved the survival of S. aureus-infected mice. Furthermore, S. aureus-induced myeloperoxidase (MPO) activity of lung homogenate and pro-inflammatory factors in bronchoalveolar lavage (BAL) fluid were suppressed by acetylharpagide. Mechanically, acetylharpagide inhibited the interaction between polyubiquitinated receptor interacting protein 1 (RIP1) and NF-κB essential modulator (NEMO), thereby suppressing NF-κB activity. In summary, these results show that acetylharpagide protects mice from S. aureus-induced ALI by suppressing the NF-κB signaling pathway. Acetylharpagide is expected to become a potential treatment for S. aureus-induced ALI.

Gastrointestinal risk factors and patient-reported outcomes of ankylosing spondylitis in Korea

Aim

This study examined the degree of gastrointestinal (GI) risk and patient‐reported outcomes including GI‐related symptoms, adherence to non‐steroidal anti‐inflammatory drugs (NSAIDs), disease activity and quality of life (QoL) in patients with ankylosing spondylitis (AS).

Methods

Cross‐sectional, observational study conducted at six nationwide, university‐based hospitals of Korea. AS patients treated with NSAIDs for at least 2 weeks were included between March and September 2016. Demographic and clinical data were gathered through a medical chart review and patient survey. GI risk was estimated using Standardized Calculator of Risk for Events (SCORE). NSAIDs adherence was investigated with Morisky Medication Adherence Scale‐8 (MMAS‐8). Disease activity and QoL were examined with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and EuroQol‐3L (EQ‐5D, EQ‐visual analog scale [EQ‐VAS]), respectively. Path analysis was implemented to estimate pathways of GI risk, GI symptoms and NSAIDs adherence to QoL.

Results

A total of 596 patients (age: 38.9 ± 12.6 years, male: 82.1%) participated in the study, of which 33.2% experienced GI symptoms during NSAID treatment, and 34.2% of them showed ongoing GI symptoms upon enrollment. According to SCORE, 37.1% of patients showed moderate to very high GI risk. No patient showed high adherence according to MMAS‐8, so 55.3% of patients with moderate adherence were considered adherent. BASDAI and QoL of the total patients were 3.5 ± 2.0, 0.6 ± 0.3 (EQ‐5D), and 67.4 ± 19.8 (EQ‐VAS), respectively. From path analyses, higher GI risk significantly lowered QoL.

Conclusion

This study suggests timely therapeutic strategies should be implemented to manage GI risk during NSAID treatment in order to effectively manage AS.

The efficacy and safety of irsogladine maleate in nonsteroidal anti-inflammatory drug or aspirin-induced peptic ulcer and gastritis

BACKGROUND/AIMS

Irsogladine maleate, an enhancer of gastric mucosal protective factors, has demonstrated its efficacy for various gastric mucosal injuries. The aim of this study was to evaluate the efficacy and safety of irsogladine for prevention of nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin-induced peptic ulcer and gastritis.

METHODS

In this multicenter, randomized, double-blind, exploratory clinical trial, 100 patients over 50 years of age who needed continuous NSAIDs or aspirin for more than 8 weeks were randomly assigned to either test group (irsogladine maleate 2 mg, twice daily, 39 patients for full analysis) or placebo group (37 patients for full analysis). Primary outcomes were incidence of peptic ulcer and ratio of modified Lanza score (MLS) 2 to 4. Secondary outcome was the number of acute erosions confirmed by endoscopy at 8 weeks. Adverse effects were also compared.

RESULTS

There were no significant differences in gastric protective effects between test and placebo groups. However, two cases of peptic ulcer in the placebo group but none in the test group were observed. These two cases of peptic ulcer were Helicobacter pylori-negative. In addition, H. pylori-negative group showed significant changes in MLS score (p = 0.0247) and edema score (p = 0.0154) after the treatment compared to those before treatment in the test group. There was no significant difference in adverse events between the two groups.

CONCLUSION

The efficacy of irsogladine maleate was found in H. pylori-negative group, suggesting its potential as a protective agent against NSAIDs or aspirin-induced peptic ulcer and gastritis.

Effect of Aspirin and ibuprofen either alone or in combination on gastric mucosa and bleeding time and on serum prostaglandin E2 and thromboxane A2 levels in the anaesthetized rats in vivo

There is much evidence that a combination of ibuprofen (IBU) and Aspirin (ASA) can antagonize the irreversible inhibition of platelet function. This study was designed to investigate the degree of gastric damage, bleeding time (BT) and fluctuations in the serum levels of prostaglandin E₂ (PGE₂) and thromboxane A₂ (TXA₂) after oral administration of ASA (200 mg/kg) and IBU (50 mg/kg) either alone or in combination in rats in vivo. The stomach was assessed for any damage either after 6 h, 18 h or 6 days and carboxymethylcellulose (1% CMC) served as a vehicle and control. ELISA was used to measure TXA₂ and PGE₂ in serum. Bleeding time was assessed using tail blood. The results show that ASA and IBU either alone or in combination can cause gastric ulceration in 25-100% of the rats at 6 and 18 h. In contrast, gastric ulceration was seen in 50% of rats with a combination of ASA given before IBU only after 6 days of oral administration. BT was unaffected either by ASA or IBU when administered alone except after 18 h for IBU. In contrast, BT was significantly reduced when IBU was administered before ASA after 18 h and 6 days (P < 0.001). Serum PGE₂ levels decreased significantly after ASA administered either alone or in combination with IBU for 6 h, 18 h and 6 days (P < 0.05). Serum TXA₂ levels were significantly reduced after 6 h, 18 h and 6 days following ASA and IBU administration except for IBU alone which caused a significant increase in serum TXA₂ 6 days after its administration (P < 0.01). It can be concluded that ASA and IBU administered either alone or in combination can cause gastric ulcers in the rat stomach after 6 h and 18 h, but less severe after 6 days. IBU either alone or in combination with ASA reduced BT only after 18 h and 6 days of administration. Together, the results show that gastric ulceration correlated well with the inhibition of serum PGE₂ and TXA₂ levels.

Does Celecoxib Potentiate the Anticoagulant Effect of Warfarin? A Randomized, Double-Blind, Controlled Trial

Background:

The management of patients who are receiving warfarin therapy and have musculoskeletal problems that require treatment with a nonsteroidal antiinflammatory drug (NSAID) is problematic because NSAID use may increase the risk for bleeding. Cyclooxygenase-2 selective NSAIDs such as celecoxib may be less likely to promote gastrointestinal bleeding; however, there are concerns that they could potentiate the anticoagulation effect of warfarin.

Objective:

To determine whether celecoxib potentiates the anticoagulant effect of warfarin, as measured by the international normalized ratio (INR).

Methods:

We performed a randomized, controlled, crossover trial to assess the effect on INR of celecoxib versus codeine (control treatment) in 15 patients who were receiving warfarin therapy and required analgesic treatment for osteoarthritis. During Phase 1 of the study, patients were randomly allocated to receive celecoxib 200 mg/day or codeine phosphate 7–15 mg 3–4 times daily for 5 weeks. During Phase 2 of the study, patients stopped the first study medication and started the other study medication; there was no drug-free interval between phases. Weekly INR testing was performed during the 10 week study period. Adopting the intent-to-treat principle, we used generalized estimating equations to analyze the data.

Results:

There was no significant difference in the mean INR values during each 5 week treatment period when patients received either celecoxib or codeine. There was, therefore, insufficient evidence to reject the hypothesis that these 2 treatments had an equal effect on the INR (mean difference [95% CI] 0.10 [-0.04 to 0.24]; p=0.16) based on mean imputation. This finding was confirmed after we repeated the analysis with multiple imputations (mean difference [95% CI] 0.093 [-0.16 to 0.35]; p = 0.47).

Conclusions:

Our results suggest that treatment with celecoxib does not potentiate the INR when taken with warfarin. Larger randomized trials are warranted to address the effects of coadministered warfarin and celecoxib on clinical outcomes.

Omega-3 polyunsaturated fatty acids as an angelus custos to rescue patients from NSAID-induced gastroduodenal damage

Nonsteroidal anti-inflammat ory drugs (NSAIDs) are one of the drug types frequently prescribed for their analgesic, anti-inflammatory, and antithrombotic actions, but carry a risk of major gastroduodenal damage from mild erosive changes to serious ulceration leading to fatal outcomes. From the long history of willow tree bark and its extracts being applied for the relief of pain and fever, the synthesis of acetylsalicylic acid, the development of selective cyclooxygenase 2 inhibitors (coxibs), and the identification of a G-protein-coupled receptor for prostaglandin, the popular combination regimen of an NSAID and a proton pump inhibitor was invented, but development was continued for further improvement. With regard to major NSAID adverse effects, gastrointestinal (GI) and cardiovascular (CV) risks still remained as problems to be solved. In this review, it is shown that n-3 polyunsaturated fatty acid (PUFA) based NSAIDs can be an angelus custos, supported with facts that an intake of essential n-3 PUFAs orchestrates concerted protective actions against two notorious side effects of NSAIDs, the aforementioned GI risk and CV risk of NSAIDs. Since pills containing n-3 PUFAs, omega-3-acid ethyl ester capsules (Lovaza, Omarcor), have already been safely prescribed to prevent atherosclerosis through lessening lipid burdening, the introduction of a drug delivery system such as a gastroretentive form of n-3 PUFA based NSAIDs will highlight newer hope for GI safety under the guarantee of reduced CV risk. Because n-3 PUFAs have been proven to attenuate cytotoxicity, inhibit lipid-raft-associated harmful signaling, and relieve oxidative stress relevant to NSAIDs, n-3 PUFA based NSAIDs will be next-generation GI-safe NSAIDs.

Pharmacological evidence for the participation of NO-cGMP-KATP pathway in the gastric protective effect of curcumin against indomethacin-induced gastric injury in the rat

Curcumin, main compound obtained from rizhoma of Curcuma longa, shows antitumoral, antioxidant, anticarcinogenic and gastric protective properties. Recently, it has been demonstrated that curcumin exerts its gastric protective action due to an increase in gastric nitric oxide (NO) levels. However, it is unknown whether these increased NO levels are associated with activation of intracellular signaling pathways. Thus, the purpose of this study was to investigate the role of NO-cGMP-KATP pathway in the gastric protective effect of curcumin during indomethacin-induced gastric injury in the rat. Adult female Wistar rats were gavaged with curcumin (3-300mg/kg, p.o.) or omeprazole (30mg/kg, p.o.) 30min before indomethacin insult (30mg/kg, p.o.). Other groups of rats were administered L-NAME (70mg/kg, i.p.; inhibitor of nitric oxide synthase), ODQ (10mg/kg, i.p.; inhibitor of soluble guanylate cyclase) or glibenclamide (1mg/kg, i.p.; blocker of ATP-sensitive potassium (KATP) channels) 30min before curcumin (30mg/kg, p.o.). 3h after indomethacin administration, rats were sacrificed and gastric injury was evaluated by determining total damaged area. A sample of gastric tissue was harvested and processed to quantify organic nitrite levels. Curcumin significantly protected against indomethacin-induced gastric injury and this effect was comparable to gastroprotective effect by omeprazole. L-NAME, ODQ and glibenclamide significantly prevented the curcumin-mediated gastric protective effect in the indomethacin-induced gastric injury model. Furthermore, curcumin administration induced a significant increase in gastric nitric oxide levels as compared to vehicle administration. Our results show for the first time that curcumin activates NO/cGMP/KATP pathway during its gastro protective action.

NSAID is inversely associated with asymptomatic gastric ulcer: local health examination data from the Korean National Health Insurance Corporation

BACKGROUND. Silent peptic ulcer has been considered to be associated with nonsteroidal anti-inflammatory drug (NSAID). The recent studies have reported no relationship between them. AIM. We attempted to investigate an association between asymptomatic peptic ulcer and NSAID in Korean adults. METHODS. The subjects were enrolled from participants visiting Myongji Hospital for health examination program of the Korean National Health Insurance Corporation. The questionnaires were designed to investigate individual medical information and gastroduodenal symptoms. RESULTS. From May 2005 to March 2009, 5459 participants were enrolled and 299 participants were excluded. Of 5160 participants, 3144 (60.9%) participants were asymptomatic and 424 (8.2%) participants had peptic ulcer. Among 3144 asymptomatic participants, NSAID-taking participants had the odds ratio of 1.4 [95% confidence interval (CI): 0.7-2.6, p = 0.339] for the risk of peptic ulcer. Among 424 peptic ulcer patients, 247 (58.3%) were asymptomatic. They had lower prevalence of NSAID use (4.9% vs. 14.7%). The asymptomatic gastric ulcer patients had smaller size and more frequent healing stage than the symptomatic gastric ulcer patients. In multivariable analysis of 424 peptic ulcer patients, NSAID patients had the odds ratio of 0.249 (95%CI: 0.115-0.536, p < 0.05) for asymptomatic peptic ulcer. In subgroup analysis of 284 gastric ulcer patients, NSAID-taking patients had the odds ratio of 0.263 (95% CI: 0.105-0.657, p = 0.004) for asymptomatic peptic ulcer. CONCLUSION. NSAID has an inverse association with asymptomatic patients with gastric peptic ulcer, but has no association with gastroduodenal symptoms in duodenal ulcer patients. These suggest that NSAID may be associated with gastroduodenal symptoms rather than masking symptoms, at least in gastric ulcer patients.

Prevalence and risk factors of asymptomatic peptic ulcer disease in Taiwan

AIM: To investigate the prevalence and risk factors of asymptomatic peptic ulcer disease (PUD) in a general Taiwanese population.

METHODS: From January to August 2008, consecutive asymptomatic subjects undergoing a routine health check-up were evaluated by upper gastrointestinal endoscopy. Gastroduodenal mucosal breaks were carefully assessed, and a complete medical history and demographic data were obtained from each patient. Logistic regression analysis was conducted to identify independent risk factors for asymptomatic PUD.

RESULTS: Of the 572 asymptomatic subjects, 54 (9.4%) were diagnosed as having PUD. The prevalence of gastric ulcer, duodenal ulcer and both gastric and duodenal ulcers were 4.7%, 3.9%, and 0.9%, respectively. Multivariate analysis revealed that prior history of PUD [odds ratio (OR), 2.0, 95% CI: 1.3-2.9], high body mass index [body mass index (BMI) 25-30: OR, 1.5, 95% CI: 1.0-2.2; BMI > 30 kg/m²: OR, 3.6, 95% CI: 1.5-8.7] and current smoker (OR, 2.6, 95% CI: 1.6-4.4) were independent predictors of asymptomatic PUD. In contrast, high education level was a negative predictor of PUD (years of education 10-12: OR, 0.5, 95% CI: 0.3-0.8; years of education > 12: OR, 0.6, 95% CI: 0.3-0.9).

CONCLUSION: The prevalence of PUD in asymptomatic subjects is 9.4% in Taiwan. Prior history of PUD, low education level, a high BMI and current smoker are independent risk factors for developing asymptomatic PUD.

Novel milk-based oral formulations: proof of concept

The aim of this study is to develop milk-based formulations for ionized and unionized lipophilic drugs. Solubility studies of the following non-steroidal anti-inflammatory drugs (NSAIDs): mefenamic acid, tolfenamic acid, ketoprofen, meloxicam, tenoxicam and nimesulide in phosphate- and glycine-NaOH buffers at nominal pH 8-12, were performed. The solubilities of cyclosporine and danazol in water-ethanol solutions were studied. NSAIDs-, cyclosporine-, danazol-, aspirin-milk oral liquid formulations were prepared by adding the appropriate volume of (i) NSAIDs-alkaline buffer solutions, (ii) water-ethanol solutions of cyclosporine and danazol and (iii) aspirin aqueous solution to 150-200ml of milk. All the non-steroidal anti-inflammatory drugs exhibited increased solubility in the alkaline buffers. The actual pH values (range 6.7-7.7) of the final NSAIDs-milk formulations were very close to milk pH. The higher ethanol content in ethanol-water mixtures increased the solubility of danazol and cyclosporine. A 15mg meloxicam-, a 100mg cyclosporine- and a 500mg aspirin-milk formulation was administered orally to healthy volunteers. All these formulations showed a satisfactory in vivo performance. The strong buffering capacity of milk that was observed and the high solubility of unionized drugs in ethanol allow the preparation of drug-milk formulations with enhanced pharmacokinetic properties.

Inhibition of endogenous hydrogen sulfide synthesis by PAG protects against ethanol-induced gastric damage in the rat

Hydrogen sulfide (H(2)S) is a gaseous mediator involved in a multitude of physiological functions; however the role of H(2)S in the gut is far from being understood completely. The aim of this study was to determine the effect of d-l-propargylglycine (PAG), an inhibitor of H(2)S synthesis, on ethanol-induced gastric injury in rat and to examine the role of l-cysteine, exogenous H(2)S, prostaglandins, non-protein sulphydryls groups, nitric oxide and K(ATP) channels in the gastroprotective effect of PAG. Administration of PAG (3.12 to 75mg/kg i.p.) or l-cysteine (0.3 to 300mg/kg, p.o.) exhibited a dose-dependent protective effect after intragastric administration of 1ml of ethanol to induce gastric injury. The gastroprotective effect of PAG (25mg/kg i.p.) was maintained after post-treatment with l-cysteine (10mg/kg p.o.), while NaHS (8.4mg/kg p.o.) inhibited this effect. The levels of gastric hydrogen sulfide were increased after ethanol-induced gastric damage and they were reverted by PAG while prostaglandin E(2) levels in gastric tissue were decreased by ethanol and PAG did not revert to this effect. Pretreatment with indomethacin (10mg/kg i.p.) and N-ethylmaleimide (NEM, 10mg/kg s.c.) resulted in a reversion of the gastroprotective effect of PAG while N(G)-nitro-l-arginine methyl ester (L-NAME, 70mg/kg s.c.), glibenclamide (1mg/kg i.p.) or diazoxide (3mg/kg i.p.) did not induce any changes. These results suggest that ethanol-induced gastric injury is related with an increment of endogenous H(2)S levels, and therefore a decrement of H(2)S levels by PAG is a benefit to protect gastric injury caused by ethanol.

Meta-analysis: incidence of endoscopic gastric and duodenal ulcers in placebo arms of randomized placebo-controlled NSAID trials

BACKGROUND

The safety of NSAIDs is often evaluated by comparison with placebo in clinical trials.

AIM

To investigate the incidence of gastric and duodenal ulcers (GDU) in placebo arms in NSAID trials over the last three decades.

METHODS

Randomized placebo-controlled trials of oral NSAIDs from 1975 to 2006 were systematically reviewed. The pooled incidence of GDU in placebo arms was calculated and compared. Meta-regression was used to identify risk factors related to the incidence of the placebo ulcer at the study level.

RESULTS

Thirty-six studies met inclusion criteria (duration of 6.5 days to 24 weeks). In total, 3.29% GDUs were reported in 36 placebo arms. The incidence of GDU in placebo arms was 0, 4.20% and 3.03% in the studies from 1975-1989, 1990-1999 and 2000-2006 respectively (P > 0.05). Eligible subjects with previous GI events and eligible subjects on co-therapy with low-lose aspirin/corticosteroids were associated with the increase in placebo ulcer incidence after adjusting for other factors.

CONCLUSIONS

The incidence of GDU in placebo arms has not changed significantly over the last three decades, although has decreased in the past 10 years. Studies show that previous GI events and co-therapy with low-dose aspirin/corticosteroids were associated with increasing GDU in placebo arms.

Endoscopic and histopathological evaluation of acute gastric injury in high-dose acetaminophen and nonsteroidal anti-inflammatory drug ingestion with suicidal intent

AIM: To evaluate endoscopic and histopathologic aspects of acute gastric injury due to ingestion of high-dose acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) with respect to some risk factors and patient characteristics.

METHODS: The study group consists of 50 patients admitted to emergency department with high dose analgesic ingestion (group I) with suicidal intent. Thirty patients with or without mild complaints of dyspepsia (group II) were selected as the control group. The study group was stratified according to the use of type and number of analgesics. Endoscopic findings were evaluated according to the Lanza score (LS), expressing the severity of the gastroduodenal damage and biopsies according to a scoring system based on histopathologic findings of acute erosive gastritis.

RESULTS: Gastroduodenal damage was signifi-cantly more severe in group I compared to group II (P < 0.01). The LS was similar in both groups Ia and Ib. However LS was significantly higher in patients who had ingested multiple NSAIDs (group Ic) compared to other patients (P < 0.01). The LS was correlated to age (P < 0.01) and total amount of drug ingested (P < 0.05) in group I; but it was not correlated with Helicobacter pylori (H pylori) infection or duration of exposure (P > 0.05). The biopsy score (BS) was higher in group I than group II (P < 0.01), and higher in group Ib than group Ia (P < 0.05).

CONCLUSION: The histopathologic damage was more severe among NSAID ingesting patients compared to those ingesting only acetaminophen and there is no significant difference in the endoscopic findings between the groups. There is no significant difference in the LS between the groups. This lack of significance is remarkable in terms of the gastric effects of high-dose acetaminophen.

Diclofenac potassium 12.5mg tablets for mild to moderate pain and fever: a review of its pharmacology, clinical efficacy and safety

Non-prescription (over-the-counter [OTC]) analgesics are used for the short-term treatment of acute painful conditions of mild to moderate intensity in everyday life. Well documented safety and efficacy, a rapid onset of action and a flexible daily dosing regimen are essential in this context. Film-coated, immediate-release, low-dose diclofenac potassium, developed for OTC use, offers a flexible daily dosing regimen with an initial dose of two tablets (2 x 12.5mg) followed by one or two tablets up to a maximum daily dose of six tablets (75 mg/day). The maximum plasma drug concentration is reached 30 minutes after administration, and the mean terminal half-life is 1-2 hours, allowing a 4- to 6-hour duration of activity, depending on the condition. Thirteen randomised, double-blind trials with both placebo and active controls have demonstrated the efficacy of diclofenac potassium 12.5mg tablets in conditions suitable for treatment with OTC medication, for example, acute lower back pain, headache, acute pain after dental extraction, symptoms of cold and influenza (including fever), and dysmenorrhoea. A single dose of diclofenac potassium 12.5mg is the lowest recommended effective dose. A two-tablet single dose of 25mg is at least as effective as ibuprofen 400mg. A flexible dosing regimen of an initial two tablets followed by one or two tablets up to a total daily dose of 75 mg is as effective as ibuprofen used in comparable fashion up to a total daily dose of 1200 mg. The incidence of adverse events in patients taking single or multiple doses of diclofenac potassium is similar to that of ibuprofen and placebo. In a safety study conducted to compare diclofenac potassium with ibuprofen for up to 3 months in patients with osteoarthritis of the knee, no differences in the pattern of adverse events were noted. There was no evidence of either hepatic injury or cardiovascular safety-related issues at any time during the study. Patients are generally capable of taking diclofenac potassium appropriately. A maximum OTC treatment duration of 5 days for pain and 3 days for fever is recommended.

Structure-based pharmacophore of COX-2 selective inhibitors and identification of original lead compounds from 3D database searching method

A four-point pharmacophore of COX-2 selective inhibitors was derived from a training set of 16 compounds, using the Catalyst program. It consists of a H bond acceptor, two hydrophobic groups and an aromatic ring, in accordance with SAR data of the compounds and with topology of the COX-2 active site. This hypothesis, combined with exclusion volume spheres representing important residues of the COX-2 binding site, was used to virtually screen the Maybridge database. Eight compounds were selected for an in vitro enzymatic assay. Five of them show COX-2 inhibition close to that of nimesulide and rofecoxib, two reference COX-2 selective inhibitors. As a result, structure-based pharmacophore generation was able to identify original lead compounds, inhibiting the COX-2 isoform.

Nabumetone: therapeutic use and safety profile in the management of osteoarthritis and rheumatoid arthritis

Nabumetone is a nonsteroidal anti-inflammatory prodrug, which exerts its pharmacological effects via the metabolite 6-methoxy-2-naphthylacetic acid (6-MNA). Nabumetone itself is non-acidic and, following absorption, it undergoes extensive first-pass metabolism to form the main circulating active metabolite (6-MNA) which is a much more potent inhibitor of preferentially cyclo-oxygenase (COX)-2. The three major metabolic pathways of nabumetone are O-demethylation, reduction of the ketone to an alcohol, and an oxidative cleavage of the side-chain occurs to yield acetic acid derivatives. Essentially no unchanged nabumetone and < 1% of the major 6-MNA metabolite are excreted unchanged in the urine from which 80% of the dose can be recovered and another 10% in faeces. Nabumetone is clinically used mainly for the management of patients with osteoarthritis (OA) or rheumatoid arthritis (RA) to reduce pain and inflammation. The clinical efficacy of nabumetone has also been evaluated in patients with ankylosing spondylitis, soft tissue injuries and juvenile RA. The optimum oral dosage of nabumetone for OA patients is 1 g once daily, which is well tolerated. The therapeutic response is superior to placebo and similar to nonselective COX inhibitors. In RA patients, nabumetone 1 g at bedtime is optimal, but an additional 0.5-1 g can be administered in the morning for patients with persistent symptoms. In RA, nabumetone has shown a comparable clinical efficacy to aspirin (acetylsalicylic acid), diclofenac, piroxicam, ibuprofen and naproxen. Clinical trials and a decade of worldwide safety data and long-term postmarketing surveillance studies show that nabumetone is generally well tolerated. The most frequent adverse effects are those commonly seen with COX inhibitors, which include diarrhoea, dyspepsia, headache, abdominal pain and nausea. In common with other COX inhibitors, nabumetone may increase the risk of GI perforations, ulcerations and bleedings (PUBs). However, several studies show a low incidence of PUBs, and on a par with the numbers reported from studies with COX-2 selective inhibitors and considerably lower than for nonselective COX inhibitors. This has been attributed mainly to the non-acidic chemical properties of nabumetone but also to its COX-1/COX-2 inhibitor profile. Through its metabolite 6-MNA, nabumetone has a dose-related effect on platelet aggregation, but no effect on bleeding time in clinical studies. Furthermore, several short-term studies have shown little to no effect on renal function. Compared with COX-2 selective inhibitors, nabumetone exhibits similar anti-inflammatory and analgesic properties in patients with arthritis and there is no evidence of excess GI or other forms of complications to date.

Time dependent risk of gastrointestinal complications induced by non-steroidal anti-inflammatory drug use: a consensus statement using a meta-analytic approach

OBJECTIVES

To provide an updated document assessing the global, NSAID-specific, and time dependent risk of gastrointestinal (GI) complications through meta-analyses of high quality studies.

METHODS

An exhaustive systematic search was performed. Inclusion criteria were: RCT or controlled study, duration of 5 days at least, inactive control, assessment of minor or major NSAID adverse effects, publication range January 1985 to January 2003. The publications retrieved were assessed during a specifically dedicated WHO meeting including leading experts in all related fields. Statistics were performed conservatively. Meta-regression was performed by regressing NSAID adjusted estimates against study duration categories.

RESULTS

Among RCT data, indolic derivates provided a significantly higher risk of GI complications related to NSAID use than for non-users: RR = 2.25 (1.00; 5.08) than did other compounds: naproxen: RR = 1.83 (1.25; 2.68); diclofenac: RR = 1.73 (1.21; 2.46); piroxicam: RR = 1.66 (1.14; 2.44); tenoxicam: RR = 1.43 (0.40; 5.14); meloxicam: RR = 1.24 (0.98; 1.56), and ibuprofen: RR = 1.19 (0.93; 1.54). Indometacin users had a maximum relative risk for complication at 14 days. The other compounds presented a better profile, with a maximum risk at 50 days. Significant additional risk factors included age, dose, and underlying disease. The controlled cohort studies provided higher estimates: RR = 2.22 (1.7; 2.9). Publication bias testing was significant, towards a selective publication of deleterious effects of NSAIDs from small sized studies.

CONCLUSION

This meta-analysis characterised the "compound" and "time" aspects of the GI toxicity of non-selective NSAIDs. The risk/benefit ratio of such compounds should thus be carefully and individually evaluated at the start of long term treatment.

[Non-opioid analgesics for perioperative pain therapy. Risks and rational basis for use]

Non-opioid analgesics play a central role in the management of postoperative pain. In this review, the pharmacology, the analgesic efficacy and the side-effects of non-opioid analgesics are summarized. First, the pharmacology of diclofenac, acetyl salicylic acid, dipyrone, acetaminophen and the COX-2 inhibitors is described. Second, the analgesic efficacy of non-opioid analgesics is analyzed for moderate pain (e.g. ambulatory surgery) and for moderate to severe pain (e.g. abdominal surgery-in combination with opioids). There is limited evidence for an additive analgesic effect of two non-opioid analgesics. Third, the major side-effects of non-opioid analgesics are discussed in relation to the pathophysiology, the frequency and the clinical relevance of these effects. In particular, side-effects on the gastrointestinal tract (ulcus formation), on coagulation (bleeding and thrombosis), on the renal (renal insufficiency), the pulmonary (bronchospasm) and the hematopoetic systems (agranulocytosis) are described. Recommendations for the clinical use of non-opioid analgesics for perioperative pain therapy are given.

The gastrointestinal tolerability of the LOX/COX inhibitor, licofelone, is similar to placebo and superior to naproxen therapy in healthy volunteers: results from a randomized, controlled trial

OBJECTIVES

Concerns exist over the safety of conventional nonsteroidal antiinflammatory drugs (NSAIDs) and selective cyclooxygenase (COX)-2 inhibitors. In experimental models, licofelone, a competitive inhibitor of 5-lipoxygenase (5-LOX) and COX-1/-2, has been shown to have good gastrointestinal and general tolerability and analgesic and antiinflammatory properties. The aim of the present endoscopy trial was to investigate the gastroduodenal tolerability of licofelone compared to placebo and naproxen in healthy volunteers.

METHODS

In this randomized, parallel-group trial, healthy volunteers received licofelone 200 mg b.i.d. (n = 30), licofelone 400 mg b.i.d. (n = 30), naproxen 500 mg b.i.d. (n = 30), or placebo (n = 31). Tolerability was assessed by gastro/duodenoscopy following 4 wk of treatment. Laboratory parameters and the incidence of ulcers and adverse events were recorded.

RESULTS

Ulcers were observed in 20% of the naproxen-treated volunteers, compared with 0% of those receiving licofelone 200 mg, licofelone 400 mg, and placebo (p= 0.024). Posttreatment mean gastric Lanza scores were similar for volunteers who received placebo or either dose of licofelone, while Lanza scores were significantly worse following naproxen therapy (p < 0.00001). The gastric mucosa was normal in 93%, 89%, and 90% of volunteers who received licofelone 200 mg, licofelone 400 mg, or placebo, respectively, compared with 37% of volunteers receiving naproxen. The incidence of adverse events did not differ significantly between licofelone 200 mg or naproxen therapy. No clinically relevant changes in laboratory parameters were observed with licofelone or naproxen therapy.

CONCLUSIONS

The results from this trial indicate that licofelone has a potential gastrointestinal safety advantage over conventional NSAID therapy, as licofelone was associated with significantly superior gastric tolerability and a lower incidence of ulcers compared with naproxen in healthy volunteers. Further trials will be required to investigate the safety and efficacy of licofelone in the treatment of diseases such as osteoarthritis.

Épidémiologie des complications gastro-duodénales associées aux anti-inflammatoires non stéroïdiens

Nonsteroidal anti-inflammatory agents (NSAIDs) are among the most widely prescribed drugs worldwide. In France, about 25% of individuals aged 40 years or older are treated with NSAIDs at least one week in the year. Although the therapeutic benefits of these drugs are substantial, their use is limited by their gastroduodenal toxicity. Dyspepsia occurs in about 30% of patients receiving NSAIDs, an approximately two-fold enhancement of risk compared with control subjects. Asymptomatic endoscopic lesions are observed in 20 to 80% of patients, depending on population characteristics, individual NSAIDs and definitions of endoscopic lesions. The risk of symptomatic ulcer, complicated ulcer (haemorrhage, perforation, stenosis) and death related to ulcer complication is multiplied by 4 in patients treated with NSAIDs. Established risk factors for NSAID-induced gastroduodenal complications are age, ulcer history, heavy alcohol consumption, individual NSAIDs, dose, association with corticoid or aspirin or anticoagulants (ulcer haemorrhage) while the role of treatment duration and Helicobacter pylori infection are controversial.

Physiopathologie des lésions gastro-duodénales induites par les anti-inflammatoires non stéroïdiens

The pathogenesis of the gastroduodenal lesions induced by non-steroidal anti-inflammatory drugs and aspirin is primarily caused by a reduction in mucosal blood flow, which is the consequence of inhibition of cyclooxygenase-producing vasodilator prostaglandins. The subsequent phase is adherence of leukocytes to the endothelium, which may depend on cyclooxygenase-2. Endothelial lesions accentuate the fall of mucosal blood flow and promote the inflammatory process in the gastric mucosa. The inflammatory process is amplified by expression of TNFalpha in polymorphonuclears induced by non-steroidal anti-inflammatory drugs. A few days after starting treatment, epithelial proliferation and increased mucosal blood flow, partly dependent on cyclooxygenase-2 and nitric oxide expression, compensates for the damaging process. Selective inhibitors of inducible cyclooxygenase-2 have reduced gastrointestinal toxicity, which could partially be explained by the protection effect of cyclooxygenase-2 on the gastrointestinal mucosa during inflammation or epithelial repair. Selective inhibitors may worsen inflammatory bowel disease. Non-steroidal inflammatory drugs and aspirin, but perhaps not selective inhibitors, increase the mucosal lesions associated with Helicobacter pylori-induced gastritis. Co-administration of selective inhibitors and aspirin leads to gastrointestinal toxicity equivalent to that of non-specific anti-inflammatory drugs.

The therapeutic potential of NO-NSAIDs

NSAIDs, including those that are selective for cyclooxygenase-2, are among the most widely used drugs. However, these drugs produce significant side effects in the gastrointestinal and cardiorenal systems, which greatly limit their utility. In recent years, a new type of anti-inflammatory agent has been developed that appears to offer significant advantages over conventional and Cox-2-selective NSAIDs. No-NSAIDs are derivatives of conventional NSAIDs, which are able to release nitric oxide over prolonged periods of time. The combination of balanced inhibition of the two main isoforms of COX with controlled release of nitric oxide yields a series of drugs that exert anti-inflammatory and analgesic activities in a wide range of settings, and have markedly reduced gastrointestinal and cardiorenal toxicity. Recent clinical trials of NO-NSAIDs have provided a 'proof of concept' that is completely consistent with pre-clinical characterization of these compounds.

Changing rates of Helicobacter pylori testing and treatment in patients with peptic ulcer disease

OBJECTIVES

The aim of this study was to identify temporal trends in the rate of Helicobacter pylori (H. pylori) testing, prevalence, and treatment among patients with peptic ulcer disease in Olmsted County, MN, from 1984 through 1997.

METHODS

All 3317 Olmsted County residents with a clinical diagnosis of peptic ulcer disease at the Mayo Clinic from 1984 through 1997 were identified. The complete medical records of an age-, sex-, and calendar year-stratified random sample were reviewed (n = 720); 298 patients (41%) had confirmed peptic ulcer disease. Changes in proportions of H. pylori testing, infection, and treatment over time were analyzed by logistic regression.

RESULTS

Of the 298 patients with confirmed peptic ulcer disease, 32% were tested for H. pylori; 36% were positive for infection, of whom 66% received antibiotic therapy. The rate of testing for H. pylori increased from 0% in 1984 to 96% in 1997, but the prevalence of infection did not change (36.4% vs 36.5%). The rate of treatment of those infected increased from 0% to 95%. By logistic regression, calendar year was associated with H. pylori testing and treatment but not infection. Recent use of nonsteroidal anti-inflammatory drugs was reported by 58% of patients, and 44% presented with GI bleeding.

CONCLUSIONS

Physicians' practice of testing and treating for H. pylori in patients with confirmed peptic ulcer disease has steadily increased over the past 14 yr. However, in our study, only 36% of these patients were infected with H. pylori, whereas the majority used nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, testing seems to be more appropriate than empiric treatment in patients with peptic ulcer disease.

Chemoprevention of esophageal adenocarcinoma by COX-2 inhibitors in an animal model of Barrett's esophagus

BACKGROUND & AIMS

Carcinogenesis in Barrett's esophagus (BE) is associated with an increased expression of cyclooxygenase (COX) 2. However, there has been no direct evidence that inhibition of COX-2 prevents cancer in BE. We studied the effect of MF-Tricyclic, a selective COX-2 inhibitor, on the development of BE and adenocarcinoma in a rat model.

METHODS

Four weeks after esophagojejunostomy, 105 Sprague-Dawley rats were randomized to a chow containing MF-Tricyclic or Sulindac, or a placebo. Ninety-six (92%) rats completed the study and were sacrificed at 28 +/- 2 weeks. The animals were assessed for the presence of cancer, tumor volume, BE, degree of inflammation, and COX-2 expression and activity.

RESULTS

MF-Tricyclic and Sulindac reduced the relative risk of development of esophageal cancer by 55% (95% confidence interval [CI] = 43%-66%, P < 0.008) and by 79% (95% CI = 68%-87%, P < 0.001), respectively, compared with controls. No significant differences were noted in the risk of esophageal cancer between the MF-Tricyclic and the Sulindac group (P = 0.34). The median tumor volume was not significantly different among the 3 groups (P = 0.081). Moderate to severe degree of inflammation was significantly more common (P = 0.005) in the control compared with the MF-Tricyclic and the Sulindac group; however, the prevalence of BE was not significantly different between groups (P = 0.98). Rats in the control group had higher tissue PGE2 level compared with the MF-Tricyclic and Sulindac groups (P = 0.038).

CONCLUSIONS

Selective and nonselective COX-2 inhibitors can inhibit inflammation, COX-2 activity, and development of adenocarcinoma induced by reflux. This provides direct evidence that COX-2 inhibitors may have chemopreventive potential in BE.

Gastrointestinal toxicity associated with nonsteroidal anti-inflammatory drugs. Epidemiologic and economic issues

The large body of literature on the gastrointestinal side effects of NSAIDs has shown consistently that populations can be identified that have a markedly elevated risk for these iatrogenic conditions. These groups include the elderly, persons with prior history of peptic ulcer disease and its complications, persons receiving anticoagulant and corticosteroid therapy, and persons who require long-term NSAID therapy, especially at high dose. It is possible that several comorbidities (e.g., rheumatoid arthritis) predispose patients to gastrointestinal complications caused by NSAIDs, but few studies have adjusted carefully for the possibility that concomitant medication use (e.g., oral anticoagulants, corticosteroids) or increased NSAID dose may account best for apparent association of comorbidities as a risk factor for serious gastrointestinal events. The role of H. pylori infection in affecting the risk of complicated ulcer disease among NSAID users remains to be fully elucidated. Low-dose aspirin for cardioprotective use is associated with an increased risk for PUBs; when used concomitantly with NSAIDs, this increases the risk of PUBs above that of the NSAID itself. Apart from the physical toll NSAID-related gastrotoxicity places on the patient, there are considerable economic consequences to patients, providers, and society. This cost presents a subject for research for those interested not only in improving the quality of patient care, but also in the prudent use of health care resources.

Pathogenesis of NSAID-induced gastroduodenal mucosal injury

The use of non-steroidal anti-inflammatory drugs (NSAIDs), even in the era of selective COX-2 inhibitors, remains limited by the ability of these agents to cause gastroduodenal ulceration and bleeding. This damage is caused mainly through the ability of these agents to inhibit prostaglandin synthesis, which has a negative impact on several components of mucosal defence. Many NSAIDs also have topical irritant effects on the epithelium which may be particularly important in the production of small intestinal injury. While the presence of acid in the lumen of the stomach may not be a primary factor in the pathogenesis of NSAID-induced gastroenteropathy it can make an important contribution to the chronicity of these lesions and to bleeding by impairing the restitution process, interfering with haemostasis and inactivating several growth factors that are important in mucosal defence and repair. Through better understanding of the pathogenesis of ulcers induced by NSAIDs, some new approaches to the development of more effective and safer anti-inflammatory drugs have been taken in recent years.

The histopathology of non-steroidal anti-inflammatory drug induced gastroduodenal damage: correlation with Helicobacter pylori, ulcers, and haemorrhagic events

AIMS

The spectrum of microscopic lesions resulting from the chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), known as chemical gastritis, remains unclear, and the variable prevalence reported in different studies makes this issue a matter of lively debate. The aim of this study was to evaluate the prevalence and importance of chemical gastritis in patients regularly taking NSAIDs. Owing to the high prevalence of Helicobacter pylori infection, particularly in subjects over 60 years of age, and in view of a possible association with damage, the presence of H pylori infection in the same tissue sample was also determined in all patients.

METHODS

One hundred and ninety seven subjects were enrolled, 118 of whom were receiving chronic treatment with NSAIDs and 79 of whom were controls, pair matched for age, sex, and clinical symptoms (ulcer-like dyspepsia or upper digestive tract haemorrhage). Antral biopsies taken during upper gastroduodenal endoscopy were assessed for chemical gastritis according to a modified version of Dixon's score, and for Helicobacter correlated chronic active gastritis, according to the updated Sydney system.

RESULTS

Chemical gastritis was identified in 11 patients taking NSAIDs (9%) and in four controls (5%) (p < 0.05). Helicobacter pylori was detected in 53 patients taking NSAIDs (45%) and in 34 controls (43%). Patients taking NSAIDs had a significantly higher number of erosions and ulcers and worse endoscores than controls. The presence of H pylori did not appear to increase histological damage, ulcer prevalence, or haemorrhagic events.

CONCLUSIONS

Chemical gastritis is present in a limited number of patients regularly taking NSAIDs, and is not strongly correlated with NSAID induced damage. In many cases of peptic ulcer or upper gastrointestinal bleeding in patients taking NSAIDs, the presence of chemical gastritis or H pylori infection cannot solely account for the development of mucosal damage.

Where is the evidence that cyclooxygenase inhibition is the primary cause of nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal injury? Topical injury revisited

In this commentary, we take a critical look at the concept that the gastrointestinal (GI) side-effects of nonsteroidal anti-inflammatory drugs (NSAIDs) are due to the ability of these drugs to inhibit cyclooxygenase-1 (COX-1) that is constitutively expressed in the GI mucosa. Indeed, development of the new "super aspirins," such as Celebrex and Vioxx, that selectively inhibit the inducible COX-2, expressed in areas of inflammation, is a direct outgrowth of this concept. We discuss evidence from both the laboratory and the clinic that appears to be inconsistent with the above concept, and cite a number of examples where the depletion of mucosal prostaglandin levels and the development of GI injury can be dissociated. Instead, we revisit the possibility that NSAID-induced GI side-effects are mostly due to the ability of these drugs to topically injure the GI mucosa. We devote the remainder of the commentary to presenting evidence from our and other laboratories that NSAIDs can directly attenuate the surface hydrophobic barrier of the GI mucosa due to their ability to bind to zwitterionic phospholipids, and that even systemically administered NSAIDs that are secreted into the bile may induce GI ulceration and/or bleeding due to phospholipid interactions and the development of topical mucosal injury.

Risk of upper gastrointestinal bleeding and perforation associated with low-dose aspirin as plain and enteric-coated formulations

BACKGROUND

The use of low-dose aspirin has been reported to be associated with an increased risk of upper gastrointestinal complications (UGIC). The coating of aspirin has been proposed as an approach to reduce such a risk. To test this hypothesis, we carried out a population based case-control study.

METHODS

We identified incident cases of UGIC (bleeding or perforation) aged 40 to 79 years between April 1993 to October 1998 registered in the General Practice Research Database. Controls were selected randomly from the source population. Adjusted estimates of relative risk (RR) associated with current use of aspirin as compared to non use were computed using unconditional logistic regression.

RESULTS

We identified 2,105 cases of UGIC and selected 11,500 controls. Among them, 287 (13.6%) cases and 837 (7.3%) controls were exposed to aspirin, resulting in an adjusted RR of 2.0 (1.7-2.3). No clear dose-effect was found within the range of 75-300 mg. The RR associated with enteric-coated formulations (2.3, 1.6-3.2) was similar to the one of plain aspirin (1.9, 1.6-2.3), and no difference was observed depending on the site. The first two months of treatment was the period of greater risk (RR= 4.5, 2.9-7.1). The concomitant use of aspirin with high-dose NSAIDs greatly increased the risk of UGIC (13.3, 8.5-20.9) while no interaction was apparent with low-medium doses (2.2, 1.0-4.6).

CONCLUSIONS

Low-dose aspirin increases by twofold the risk of UGIC in the general population and its coating does not modify the effect. Concomitant use of low-dose aspirin and NSAIDs at high doses put patients at a specially high risk of UGIC.

Approaches to nonsteroidal anti-inflammatory drug use in the high-risk patient

Nonsteroidal anti-inflammatory drugs (NSAIDs) are probably the most common cause of gastroduodenal injury in the United States today. Approximately half of patients who regularly take NSAIDs have gastric erosions, and 15%-30% have ulcers when they are examined endoscopically. However, the incidence of clinical gastrointestinal (GI) events caused by NSAIDs is much lower. Clinical upper GI events may occur in 3%-4.5% of patients taking NSAIDs, and serious complicated events develop in approximately 1.5%. However, the risk varies widely in relationship to clinical features such as history of ulcers or GI events, age, concomitant anticoagulant or steroid use, and NSAID dose. This review discusses the risks of clinical GI disease in NSAID users, the predictors of increased risk, and strategies for prevention of NSAID-associated GI disease.

Gastrointestinal bleeding associated with myocardial infarction

Gastrointestinal (GI) bleeding associated with myocardial infarcation (MI) often presents as a distinct syndrome that differs from either disease alone. MI is frequently overlooked in the setting of severe GI bleeding because the symptoms and signs of MI are frequently overshadowed by the severe bleeding. GI bleeding, particularly when massive, may precipitate MI from hypovolemia, hemodynamic compromise, and myocardial hypoperfusion. Esophagogastroduodenoscopy is safe in relatively clinically stable patients after MI and is indicated to evaluate significant upper GI bleeding.

[Digestive complications of aspirin]

INTRODUCTION

This review focuses on aspirin-related gastrointestinal side-effects and the mechanism by which aspirin causes gastrointestinal damage.

CURRENT KNOWLEDGE AND KEY POINTS

Aspirin causes direct gastric damage by topical irritant effects and indirect damage via systemic inhibition of cyclooxygenase synthesis and microcirculation injury. The question of a possible synergistic relation between the presence of Helicobacter pylori infection and aspirin use on gastric damage is not resolved. The pathogenesis of small intestinal and colonic damage is less well understood; an increase in intestinal permeability and free radical synthesis are suggested. Gastric damage predominates. Gastroduodenal lesions from aspirin have been documented in endoscopy studies. The lesions occur rapidly, even for low-dose aspirin. The association of aspirin consumption with upper gastrointestinal bleeding has been well established. The main risk factors are advanced age, concomitant use of nonsteroidal antiinflammatory drugs and history of ulcer. Low-dose aspirin are associated with increased risk of gastrointestinal bleeding and this risk is dose-dependant. Chronic aspirin consumption can cause iron deficiency anaemia. Uncomplicated gastric ulcer (but not uncomplicated duodenal ulcer) is associated with aspirin use, with relative risk 3. Other upper gastrointestinal complications have been reported: stenosis and perforation. Aspirin can also damage other areas of the gastrointestinal tract. Oesophageal injuries (oesophagitis and stricture) have been reported. Aspirin is associated with variceal bleeding episodes in patients with cirrhosis. The adverse effects of aspirin on the small bowel are perforation, bleeding, increasing permeability. The adverse effects of aspirin on the large intestine are perforation, bleeding, collagenous colitis and anorectal stenosis with suppositories containing aspirin. Direct clinical data regarding prophylaxis with co-administration of a protective drug are not yet available for aspirin.

FUTURE PROSPECTS AND PROJECTS

Patients should be made aware of adverse gastrointestinal effects due to aspirin. Further studies regarding prophylactic therapy of low-dose aspirin induced gastroduodenal lesions, which identify a subset of patients who may be at higher risk than the low-dose aspirin population as a whole, are warranted.

Recent nonsteroidal anti-inflammatory drug use increases the risk of early recurrence of bleeding in patients presenting with bleeding ulcer

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use is a well-known risk factor for ulcer formation and ulcer complications. The purpose of this study was to determine whether recent NSAID use increases the risk of early recurrence of bleeding in patients who present with bleeding ulcer.

METHODS

Clinical and endoscopic data were collected prospectively. Dose, frequency, and duration of recent NSAID use were quantified. Recent NSAID use was defined as consumption of over-the-counter or prescription NSAIDs or aspirin for at least 5 days of the 2-week period preceding the index episode of bleeding. Endoscopy was performed within 24 hours of admission to confirm the source of bleeding and endoscopic intervention was applied for stigmata of bleeding. Early recurrence of bleeding was defined as melena, hematochezia or blood per nasogastric tube with a 2 gm or greater decrease in hemoglobin during a period of 48 hours, occurring less than 2 weeks from index episode of bleeding.

RESULTS

One hundred twenty patients (52 NSAID users and 68 nonusers) were enrolled in the study; mean age was 56 years. NSAID users were older than nonusers (p = 0.003); nonusers were more likely to have a history of ulcer disease (p < 0.0005) and higher prevalence of Helicobacter pylori infection (p = 0.05). Recent NSAID use was associated with a significantly higher frequency of early recurrence of bleeding and in-hospital recurrent bleeding compared with nonusers: 19% vs. 6%, p = 0.02, and 17% vs. 6%, p = 0.04, respectively. In multivariate logistic regression analysis, the significant association between recent NSAID use and early recurrence of bleeding persisted (p = 0.0048) while controlling for age and other covariates.

CONCLUSIONS

Recent NSAID use predisposes bleeding ulcer patients to early and in-hospital recurrent bleeding, probably via its effects on platelet function, mucosal prostaglandins, and ulcer healing.

How do NSAIDs cause ulcer disease?

Gastroduodenal ulceration and bleeding are the major limitations to the use of non-steroidal anti-inflammatory drugs (NSAIDs). The development of safer NSAIDs or of effective therapies for the prevention of the adverse effects of existing NSAIDs requires a better understanding of the pathogenesis of NSAID-induced ulcer disease. NSAIDs can cause damage to the gastroduodenal mucosa via several mechanisms, including the topical irritant effect of these drugs on the epithelium, impairment of the barrier properties of the mucosa, suppression of gastric prostaglandin synthesis, reduction of gastric mucosal blood flow and interference with the repair of superficial injury. The presence of acid in the lumen of the stomach also contributes to the pathogenesis of NSAID-induced ulcers and bleeding, by impairing the restitution process, interfering with haemostasis and inactivating several growth factors that are important in mucosal defence and repair. In recent years, a fuller understanding of the pathogenesis of NSAID-induced ulcer disease has facilitated some new, very promising approaches to the development of stomach-sparing NSAIDs.

Comparative toxicity of nonsteroidal anti-inflammatory drugs

To compare the gastrointestinal (GI) toxicities of various nonsteroidal anti-inflammatory drugs (NSAIDs), it is first necessary to dismantle the imprecise entity "NSAID gastropathy" into its component conditions, and understand their pathogenesis. In this article, toxicities are reviewed only in so far as they affect the upper GI tract, the site of approximately 80% of GI injuries caused by NSAIDs. The phenomena discussed are platelet dysfunction, causing hemorrhage from various lesions, including but not confined to ulcers; various mucosal injuries, ranging from small erosions to large ulcers; and "complications," such as bleeding or perforations, causing admission to hospital, that may arise from ulcers but may also arise from other lesions. Ulcers, when complicated, may either be those caused by an NSAID or "peptic" ulcers that preceded NSAID therapy (having a high prevalence in the population) and gave rise to complications resulting from NSAID effects on platelets, tissues, or biologic processes, for example, healing, necrosis/apoptosis, leukocyte adherence, vasoconstriction, or generation of free radicals. NSAIDs have been compared in various ways, including fecal blood loss, endoscopic lesion development, prospective preclinical cohort studies measuring perforations, ulcers, and bleeds, post-marketing surveillance studies, and studies of the incidence of serious adverse events in populations followed in large databases linked to each individual patient record with regard to drug consumption and outcome. All methods show considerable differences between NSAIDs. Modern studies on the relative toxicities of NSAIDs are summarized and reviewed, and a number of marketed and emerging drugs that appear less toxic than classic NSAIDs are identified.

Enteric coating of aspirin significantly decreases gastroduodenal mucosal lesions

BACKGROUND

Low-dose aspirin (acetylsalicylic acid, ASA) increases the risk of developing peptic ulceration.

AIM

To investigate the gastroduodenal mucosal tolerability of enteric-coated ASA (EC-ASA) 100 mg/day compared to either placebo (study 1) or plain ASA 100 mg/day (study 2) in healthy volunteers.

METHODS

Study 1: In this double-blind study 18 volunteers received randomized dosing with either EC-ASA 100 mg or placebo for 15 days. Study 2: 41 volunteers underwent randomized 7-day dosing of either EC-ASA 100 mg or plain ASA 100 mg in this double-blind, parallel-group, comparison study. In both studies acute gastroduodenal mucosal lesions were assessed endoscopically before treatment, on the morning of day 1 after the first dose (only in study 2), and on the morning after the last dose of the test medication.

RESULTS

Study 1 did not reveal any significant differences between the lesion scores of EC-ASA and placebo. In contrast, in study 2 significantly higher total gastroduodenal mucosal lesion scores were observed on day 1 after the first dose and after 7 days of dosing with plain ASA (mean sum of the lesion scores in the gastric fundus, body, antrum and in the duodenal bulb: day 1: plain ASA 3.95+/-3.38 vs. EC-ASA 1.43+/-1.91, P = 0.03; day 7: plain ASA 6.35+/-4.10 vs. EC-ASA 2.00+/-2.02, P = 0.0004). Tolerance of the test drugs was good, and no other adverse events were observed.

CONCLUSIONS

Enteric-coated aspirin 100 mg/day causes significantly less gastroduodenal damage over 7 days than the same dose of plain aspirin, when given to healthy subjects. There was little gastric injury and no significant differences between EC-ASA and placebo in this respect.

Inhibition and uncoupling of oxidative phosphorylation by nonsteroidal anti-inflammatory drugs: study in mitochondria, submitochondrial particles, cells, and whole heart

The effects of the anti-inflammatory drugs diclofenac, piroxicam, indomethacin, naproxen, nabumetone, nimesulide, and meloxicam on mitochondrial respiration, ATP synthesis, and membrane potential were determined. Except for nabumetone and naproxen, the other drugs stimulated basal and uncoupled respiration, inhibited ATP synthesis, and collapsed membrane potential in mitochondria incubated in the presence of either glutamate + malate or succinate. Plots of membrane potential versus ATP synthesis (or respiration) showed proportional variations in both parameters, induced by different concentrations of nimesulide, meloxicam, piroxicam, or indomethacin, but not by diclofenac. The activity of the adenine nucleotide translocase was blocked by diclofenac and nimesulide; diclofenac also slightly inhibited mitochondrial ATPase activity. Naproxen did not affect any of the mitochondrial parameters measured. Nabumetone inhibited respiration, ATP synthesis, and membrane potential in the presence of glutamate + malate, but not with succinate. NADH oxidation in submitochondrial particles also was inhibited by nabumetone. Nabumetone inhibited O2 uptake in intact cells and in whole heart, whereas the other five drugs stimulated respiration. These observations revealed that in situ mitochondria are an accessible target. Except for diclofenac, a negative inotropic effect on cardiac contractility was induced by the drugs. The data indicated that nimesulide, meloxicam, piroxicam, and indomethacin behaved as mitochondrial uncouplers, whereas nabumetone exerted a specific inhibition of site 1 of the respiratory chain. Diclofenac was an uncoupler too, but it also affected the adenine nucleotide translocase and the H+-ATPase.

The use of analgesics in the management of pain in rheumatic diseases

Pain is the most common complaint of patients who see rheumatologists. In this article, the current treatment options for pain are reviewed; these include acetaminophen, nonsteroidal anti-inflammatory drugs, new specific cyclooxygenase-2 inhibitors, opioid analgesics, centrally acting muscle relaxants, antidepressants, and topical analgesics and counterirritants. The doses of medication and known adverse effects of these medications are highlighted.

Effects of alendronate on gastric and duodenal mucosa

OBJECTIVES

This single-center, double-blind, randomized study assessed the effect of alendronate 5 and 10 mg on the gastroduodenal mucosa.

METHODS

Overall, 95 postmenopausal women without a recent history of major upper gastrointestinal (GI) disease and not taking gastric-irritant drugs, were screened with an upper GI endoscopy. Fourteen women (15% of the total) were found to have baseline endoscopic gastric and/or duodenal abnormalities, including mucosal hemorrhages (n = 4), erosions (n = 11), and ulcers (n = 3). Two additional women had baseline esophageal abnormalities. Thus, 79 postmenopausal women (mean age 51 yr, range 41-64 yr), free of esophageal, gastric and/or duodenal erosions or ulcer, were enrolled. Subjects received placebo, alendronate 5 mg/day or 10 mg/day, or aspirin 650 mg q.i.d. for 14 days. Endoscopy was repeated on Day 8 and on Day 15. Gastric and duodenal mucosae were graded separately using a 5-point scale for erosive mucosal injury.

RESULTS

The proportions of subjects with a gastric or duodenal erosion score > or = 2 (presence of at least one mucosal erosion) on either Day 8 or 15 were four of 22 (18.2%) in the placebo group; four of 22 (18.2%) in the alendronate 5 mg group; five of 21 (23.8%) in the alendronate 10 mg group; and 14 of 14 (100.0%) in the aspirin group. Thirty-five of 76 (46%) subjects were H. pylori-positive (Pyloritek test), and were equally distributed across treatment groups.

CONCLUSIONS

Alendronate 5 and 10 mg/day for 2 wk was associated with a lower incidence of gastric erosions than aspirin. The incidence of gastric erosions in the alendronate groups did not differ significantly from the placebo group. In this study, unlike aspirin, alendronate did not induce gastric erosions.

Aspirin-induced gastritis, like Helicobacter pylori-induced gastritis disinhibits acid secretion in humans: relation to cytokine expression

BACKGROUND

Helicobacter pylori infection contributes to hypergastrinemia and hypersecretion of acid by blocking inhibitory reflex pathways to gastrin and parietal cells normally activated by antral distention. Our aim was to investigate whether a similar blockade of inhibitory responses could be provoked by inducing gastritis with aspirin, thus implicating a common inflammatory component, possibly a proinflammatory cytokine(s).

METHODS

We studied the effects of antral distention on stimulated acid secretion and gastrin release in H. pylori-negative volunteers, before and after 3 days of aspirin therapy (2 g daily). Immediately before the examinations, the severity of gastric mucosal injury was evaluated macroscopically and histologically, and the production of interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma was determined by immunohistochemistry.

RESULTS

Most subjects had severe gastric injury after aspirin therapy, resulting in a substantially increased production of IL-1beta, IL-6, and IL-8 but not of TNF-alpha and IFN-gamma in the antral mucosa. In these subjects the acid-inhibitory response was abolished or markedly reduced. Conversely, aspirin therapy failed to affect the gastrin release in all subjects studied.

CONCLUSIONS

The disinhibition of acid secretion in response to antral distention is a joint feature of the gastritis induced by aspirin and H. pylori infection, possibly related to the increased production of IL-1beta, IL-6, and IL-8. The H. pylori-related hypergastrinemia apparently has a different background.

Mechanism of action of nonsteroidal anti-inflammatory drugs

Salicylic acid and salicylates, obtained from natural sources, have long been used as medicaments. Salicylic acid was chemically synthesized in 1860 and was used as an antiseptic, an antipyretic, and an antirheumatic. Almost 40 years later, aspirin was developed as a more palatable form of salicylate. Soon after, other drugs having similar actions to aspirin were discovered, and the group was termed the "aspirin-like drugs" (also now termed the nonsteroidal anti-inflammatory drugs [NSAIDs]). Twenty-five years ago, it was proposed that the mechanism of action of NSAIDs was through their inhibition of prostaglandin biosynthesis. Since then, there has been general acceptance of the concept that these drugs work by inhibition of the enzyme cyclo-oxygenase (COX), which we now know to have at least two distinct isoforms: the constitutive isoform, COX-1, and the inducible isoform, COX-2. COX-1 has clear physiologic functions. Its activation leads, for instance, to the production of prostacyclin, which when released by the endothelium is antithrombogenic and when released by the gastric mucosa is cytoprotective. COX-2, discovered 6 years ago, is induced by inflammatory stimuli and cytokines in migratory and other cells. It is therefore attractive to suggest that the anti-inflammatory actions of NSAIDs are due to inhibition of COX-2, whereas the unwanted side-effects, such as irritation of the stomach lining, are due to inhibition of COX-1. Drugs that have the highest COX-2 activity and a more favorable COX-2: COX-1 activity ratio will have a potent anti-inflammatory activity with fewer side-effects than drugs with a less favorable COX-2: COX-1 activity ratio. The identification of selective inhibitors of COX-2 will therefore lead to advances in therapy.

Selective induction of cyclo-oxygenase-2 activity in the permanent human endothelial cell line HUV-EC-C: biochemical and pharmacological characterization

1. Cyclo-oxygenase (COX), the enzyme responsible for the conversion of arachidonic acid (AA) to prostaglandin H2 (PGH2), exists in two forms, termed COX-1 and COX-2 which are encoded by different genes. COX-1 is expressed constitutively and is known to be the site of action of aspirin and other nonsteroidal anti-inflammatory drugs. COX-2 may be induced by a series of pro-inflammatory stimuli and its role in the development of inflammation has been claimed. 2. Endothelial cells are an important physiological source of prostanoids and the selective induction of COX-2 activity has been described for finite cultures of endothelial cells, but not for permanent endothelial cell lines. 3. The HUV-EC-C line is a permanent endothelial cell line of human origin. We have determined the COX activity of these cells under basal conditions and after its exposure to two different stimuli, phorbol 12-myristate 13-acetate (PMA) and interleukin-1 beta (IL-1 beta). 4. Both PMA and IL-1 beta produced dose- and time-dependent increases of the synthesis of the COX-derived eicosanoids. These increases were maximal after the treatment with 10 nM PMA for 6 to 9 h. Under these conditions, the main eicosanoid produced by the cells was PGE2. 5. The increase of COX activity by PMA or IL-1 beta correlated with an increase of the enzyme's apparent Vmax, whilst the affinity for the substrate, measured as apparent Km, remained unaffected. 6. Treatment of the cells with PMA induced a time-dependent increase in the expression of both COX-1 and COX-2 mRNAs. Nevertheless, this increase was reflected only as an increase of the COX-2 isoenzyme at the protein level. 7. The enzymatic activity of the PMA-induced COX was measured in the presence of a panel of enzyme inhibitors, and the IC50 values obtained were compared with those obtained for the inhibition of human platelet COX activity, a COX-1 selective assay. Classical non-steroidal anti-inflammatory drugs (NSAIDs) inhibited both enzymes with varying potencies but only the three compounds previously shown to be selective COX-2 inhibitors (SC-58125, NS-398 and nimesulide) showed higher potency towards the COX of PMA-treated HUV-EC-C. 8. Overall, it appears that the stimulation of the HUV-EC-C line with PMA selectively induces the COX-2 isoenzyme. This appears to be a suitable model for the study of the physiology and pharmacology of this important isoenzyme, with a permanent endothelial cell line of human origin.