Toxicity Of Nonsteroidal Anti-inflammatory Drugs Research Articles

Phosphatidylcholine Attenuates Aggregation of Nonsteroidal Anti-Inflammatory Drugs with Bile Acid

Prolonged usage of nonsteroidal anti-inflammatory drugs (NSAIDs) causes gastrointestinal injury. Bile acids and phospholipids have been shown to exasperate and attenuate NSAIDs' toxicity, respectively. However, the molecular mechanisms underlying these effects remain undetermined. We have investigated the molecular interactions in various mixtures of indomethacin (Indo), a commonly used NSAID, and cholic acid (CA), a bile acid, in the presence and absence of palmitoyloleylphosphatidylcholine (POPC) lipids. We found that CA and Indo spontaneously form mixed micelles, with the hydrophobic face of CA and hydrophobic region of Indo forming the core. Increasing the Indo concentration resulted in more stable and larger aggregates that contain a progressively larger number of Indo molecules. More dynamic aggregates with a maximum size of 15 were obtained when the relative concentration of CA was higher. The mixture of CA, Indo, and POPC also led to ternary mixed micelles in which CA and Indo distribute almost uniformly on the surface such that intra-CA, intra-Indo, and CA/Indo interactions are minimized. A number of previous reports have shown that Indo perforates the cell membrane in the presence of bile acids (e.g., Petruzzelli et al., (2006) Dig. Dis. Sci., 51, 766-774). We propose that this may be related to the stable, highly charged, large CA/Indo binary micelles observed in our simulations. Similarly, the diminished ability of the CA/Indo mixture to aggregate in the presence of POPC may partly explain the lower toxicity of PC-conjugated NSAIDs.

Evaluation of PIK3CA Mutation As a Predictor of Benefit From Nonsteroidal Anti-Inflammatory Drug Therapy in Colorectal Cancer

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) protect against colorectal cancer (CRC) and are associated with reduced disease recurrence and improved outcome after primary treatment. However, toxicities of NSAIDs have limited their use as antineoplastic therapy. Recent data have suggested that the benefit of aspirin after CRC diagnosis is limited to patients with PIK3CA-mutant cancers. We sought to determine the predictive utility of PIK3CA mutation for benefit from both cyclooxygenase-2 inhibition and aspirin. We performed molecular analysis of tumors from 896 participants in the Vioxx in Colorectal Cancer Therapy: Definition of Optimal Regime (VICTOR) trial, a large randomized trial comparing rofecoxib with placebo after primary CRC resection. We compared relapse-free survival and overall survival between rofecoxib therapy and placebo and between the use and nonuse of low-dose aspirin, according to tumor PIK3CA mutation status. We found no evidence of a greater benefit from rofecoxib treatment compared with placebo in patients whose tumors had PIK3CA mutations (multivariate adjusted hazard ratio [HR], 1.2; 95% CI, 0.53 to 2.72; P = .66; (P)INTERACTION = .47) compared with patients with PIK3CA wild-type cancers (HR, 0.87; 95% CI, 0.64 to 1.16; P = .34). In contrast, regular aspirin use after CRC diagnosis was associated with a reduced rate of CRC recurrence in patients with PIK3CA-mutant cancers (HR, 0.11; 95% CI, 0.001 to 0.832; P = .027; (P)INTERACTION = .024) but not in patients lacking tumor PIK3CA mutation (HR, 0.92; 95% CI, 0.60 to 1.42; P = .71). Although tumor PIK3CA mutation does not predict benefit from rofecoxib treatment, it merits further evaluation as a predictive biomarker for aspirin therapy. Our findings are concordant with recent data and support the prospective investigation of adjuvant aspirin in PIK3CA-mutant CRC.

Pharmacogenetics and pharmacogenomics in rheumatology

Pharmacogenetics and pharmacogenomics deal with possible associations of a single genetic polymorphism or those of multiple gene profiles with responses to drugs. In rheumatology, genes and gene signatures may be associated with altered efficacy and/or safety of anti-inflammatory drugs, disease-modifying antirheumatic drugs (DMARDs) and biologics. In brief, genes of cytochrome P450, other enzymes involved in drug metabolism, transporters and some cytokines have been associated with responses to and toxicity of non-steroidal anti-inflammatory drugs, corticosteroids and DMARDs. The efficacy of biologics may be related to alterations in cytokine, chemokine and FcγR genes. Numerous studies reported multiple genetic signatures in association with responses to biologics; however, data are inconclusive. More, focused studies carried out in larger patient cohorts, using pre-selected genes, may be needed in order to determine the future of pharmacogenetics and pharmacogenomics as tools for personalized medicine in rheumatology.

Rebamipide Helps Defend Against Nonsteroidal Anti-Inflammatory Drugs Induced Gastroenteropathy: A Systematic Review and Meta-Analysis

Gastrointestinal toxicity of nonsteroidal anti-inflammatory drugs (NSAIDs) has been perplexing most clinicians and users of NSAIDs. Rebamipide is increasingly advocated as a candidate option for the prevention of NSAIDs induced gastrointestinal mucosal injury. To assess the efficacy and the safety of rebamipide for the prevention and treatment of NSAID-induced gastroenteropathy. PubMed, Embase, Web of Science, Google Scholar, the Cochrane Library, Japan Science and Technology Information Aggregator, and China Biology Medicine Disc were searched up to December 2011. Randomized controlled trials (RCTs) recruiting subjects with co-prescriptions of NSAIDs and rebamipide were eligible. Efficacy and safety of rebamipide were reevaluated, and dichotomous data were pooled to obtain relative risk (RR) with a 95 % confidence interval. Heterogeneity and publication bias were assessed by the inconsistency index statistic and funnel plot analysis, respectively. The search identified 338 citations, and 15 RCTs including 965 individuals were eligible. In general, rebamipide acted better than placebo against short-term NSAID-induced gastroduodenal injury. Separate studies showed rebamipide was equal to or not superior to traditional strategies (including PPIs, H2RA and misoprostol treatment). Especially, rebamipide showed a beneficial effect against the small bowel damage (total RR = 2.70, 95 % confidence interval = 1.02-7.16, P = 0.045) when compared with placebo group. The average incidence of adverse events was about 36.1 % (0-70.0 %) but no serious event was recorded. Current evidences show rebamipide is effective and safe for defending against NSAID-induced gastroduodenal and lower-gastrointestinal injuries. However, more well-designed trials should be conducted to fully confirm the practical value of rebamipide.

Overuse of Prescription and OTC Non-Steroidal Anti-Inflammatory Drugs in Patients with Rheumatoid Arthritis and Osteoarthritis

Non-steroidal anti-inflammatory drugs (NSAIDs) have been demonstrated to have significant cardiovascular and gastrointestinal toxicity; high dose of intake and concomitant use of multiple compounds or corticosteroids are factors that increase the risk of NSAID toxicity. In this paper we described our experience on NSAIDs misuse (both prescribing and OTC formulations), particularly relevant in the setting of rheumatoid arthritis (39.5 percent of patients) and osteoarthritis (47 percent of patients). We also evaluated causes underlying NSAIDs misuse (e.g. not satisfactory pain control, other painful conditions, etc).

Rheumatology and the Kidney, 2nd Edition

Dwomoa Adu, Paul Emery, Michael Madaio. Oxford: Oxford University Press, April 2012, 466 pages, $78 US This book represents a joint effort by rheumatologists and nephrologists to describe many of the diseases treated by both subspecialties. Although many chapters are devoted to lupus nephritis and vasculitis [especially antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis], the book covers a multitude of topics from nephrotoxicity of drugs used in rheumatology including analgesic nephropathy and nonsteroidal antiinflammatory drug toxicity to gout, …

Aggregation behavior of ibuprofen, cholic acid and dodecylphosphocholine micelles

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used to treat chronic pain and inflammation. However, prolonged use of NSAIDs has been known to result in Gastrointestinal (GI) ulceration/bleeding, with a bile-mediated mechanism underlying their toxicity to the lower gut. Bile acids (BAs) and phosphatidylcholines (PCs), the major components of bile, form mixed micelles to reduce the membrane disruptive actions of monomeric BAs and simple BA micelles. NSAIDs are suspected to alter the BA/PC balance in the bile, but the molecular interactions of NSAID–BA or NSAID–BA–PC remain undetermined. In this work, we used a series of all-atom molecular dynamics simulations of cholic acid (CA), ibuprofen (IBU) and dodecylphosphocholine (DPC) mixtures to study the spontaneous aggregation of CA and IBU as well as their adsorption on a DPC micelle. We found that the size of CA–IBU mixed micelles varies with their molar ratio in a non-linear manner, and that micelles of different sizes adopt similar shapes but differ in composition and internal interactions. These observations are supported by NMR chemical shift changes, NMR ROESY crosspeaks between IBU and CA, and dynamic light scattering experiments. Smaller CA–IBU aggregates were formed in the presence of a DPC micelle due to the segregation of CA and IBU away from each other by the DPC micelle. While the larger CA–IBU aggregates arising from higher IBU concentrations might be responsible for NSAID-induced intestinal toxicity, the absence of larger CA–IBU aggregates in the presence of DPC micelles may explain the observed attenuation of NSAID toxicity by PCs.

Toxicity of non-steroidal anti-inflammatory drugs: a review of melatonin and diclofenac sodium association.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the purpose of anti-inflammation, antipyretic, and analgesia. For this aim, they are used for the alleviation of pain, fever, and inflammation associated with rheumatoid arthritis, sports injuries, and temporary pain. However, treatment with NSAIDs may be accompanied by adverse effects such as gastrointestinal damage and platelet dysfunction. As with the other NSAIDs, diclofenac sodium (sodium-(o-((2,6-dichlorophenyl)-amino)-phenyl)-acetate) (DS), an NSAID, has potent anti-inflammatory, analgesic, and antipyretic effects. However, treatment with DS may cause some adverse cerebral and cerebellar effects such as convulsions, disorientation, hallucination, and loss of consciousness. Melatonin (MLT) is a free-radical scavenger and possesses antioxidant properties. It has been reported to easily cross the blood-brain barrier, and is found in high concentrations in the brain after exogenous administration. It is also a neuroprotector in a wide range of conditions affecting the central nervous system CNS due to its free-radical scavenging activities and lipophilic-hydrophilic properties. Neuroprotective actions of MLT have been discovered in both in vitro and in vivo, and are a powerful scavenger of oxygen and nitrogen free radicals. Thus, MLT can protect the cell membrane, organelles, and core against free-radical damage. Therefore, it has been postulated that exogenous MLT acts as a neuroprotector contrary to DS neurotoxicity. In this review, we aimed to discuss the possible neuroprotective effects of MLT on DS toxicity.

NSAIDs pharmacotherapy and CYP2C9 allele frequency in pediatric sickle cell disease patients

Nonsteroidal, anti-inflammatory drugs (NSAIDs) used to treat prodromal signs and early forms of vaso-occlusive (VOC) pain in pediatric sickle cell disease (SCD) patients are substrates of the polymorphic cytochrome P450 CYP2C9 enzyme. Ethnic variation in CYP2C9 allelic frequency and ontogeny are important considerations for NSAIDs efficacy and toxicity in pediatric patients. Understanding the association between CYP2C9 genotypes and phenotypes and using this information for clinical studies of NSAIDs metabolism could facilitate personalized analgesic therapy.

The role of paracetamol and nonsteroidal anti-inflammatory drugs in addition to WHO Step III opioids in the control of pain in advanced cancer. A systematic review of the literature

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol are used widely in the management of mild to moderate cancer pain and are frequently combined with opioids in the treatment of moderate to severe pain. Aim: To perform a systematic literature review of the evidence of the efficacy and toxicity of NSAIDs or paracetamol added to WHO Step III opioid treatment for cancer pain. Design and data sources: A systematic literature review of MedLine, EMBASE and Cochrane Central register of controlled trials database was carried out using both text words and MeSH/EMTREE terms. Results: Seven eligible papers were retrieved from the new search and five from the Cochrane review. Five of seven studies showed an additive effect of NSAIDs when combined with opioids either by improving analgesia (three studies) or by reducing the opioid dose (two studies). Paracetamol was only marginally effective in one of five trials. The study designs were not adequate to assess differences in side effects between the opioids alone and opioids in combination with NSAIDs or paracetamol. Conclusions: The evidence from the available clinical trials is of limited amount and quality, but it weakly supports the proposal that the addition of an NSAIDs to WHO Step III opioids can improve analgesia or reduce opioid dose requirement. There is insufficient evidence to support the use of paracetamol in combination with Step III opioids. Data on the toxicity of NSAIDs in this indication are insufficient owing to the small number of patients and the short duration of treatment reported in the studies.

Differential involvement of mitochondrial dysfunction, cytochrome P450 activity, and active transport in the toxicity of structurally related NSAIDs

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of pain and inflammation. However, this group of drugs is associated with serious adverse drug reactions. Previously, we studied the mechanisms underlying toxicity of the NSAID diclofenac using Saccharomycescerevisiae as model system. We identified the involvement of several mitochondrial proteins, a transporter and cytochrome P450 activity in diclofenac toxicity. In this study, we investigated if these processes are also involved in the toxicity of other NSAIDs. We divided the NSAIDs into three classes based on their toxicity mechanisms. Class I consists of diclofenac, indomethacin and ketoprofen. Mitochondrial respiration and reactive oxygen species (ROS) play a major role in the toxicity of this class. Metabolism by cytochrome P450s further increases their toxicity, while ABC-transporters decrease the toxicity. Mitochondria and oxidative metabolism also contribute to toxicity of class II drugs ibuprofen and naproxen, but another cellular target dominates their toxicity. Interestingly, ibuprofen was the only NSAID that was unable to induce upregulation of the multidrug resistance response. The class III NSAIDs sulindac, ketorolac and zomepirac were relatively non-toxic in yeast. In conclusion, we demonstrate the use of yeast to investigate the mechanisms underlying the toxicity of structurally related drugs.

Sub-lethal effects induced by a mixture of three non-steroidal anti-inflammatory drugs (NSAIDs) on the freshwater bivalve Dreissena polymorpha

Non-steroidal anti-inflammatory drugs (NSAIDs) are the sixth top-selling drugs worldwide and are commonly found in freshwater ecosystems in the high ng/l to low μg/l range. Recent studies have investigated both the acute and the chronic toxicity of single NSAIDs on different biological models, but these studies have completely neglected the fact that, in the environment, non-target organisms are exposed to mixtures of drugs that have unforeseeable toxicological behavior. This work investigated the sub-lethal effects induced by a mixture of three common NSAIDs, namely, diclofenac, ibuprofen and paracetamol, on the freshwater bivalve, the zebra mussel (Dreissena polymorpha). The mussels were exposed to three different environmental concentrations of the mixture (Low, Mid and High). A multi-biomarker approach was used to highlight cyto-genotoxic effects and the imbalance of the oxidative status of the treated specimens. The Neutral Red Retention Assay (NRRA) was used as a biomarker of cytotoxicity, whereas the activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione S-transferase were measured to assess the role played by the oxidative stress enzymes. In addition, the single cell gel electrophoresis assay, the DNA Diffusion assay and the micronucleus test were used to investigate possible genotoxic effects. According to our NRRA results, each treatment was able to induce a significant cellular stress in bivalves, probably due to the raise of oxidative stress, as indicated by the alteration of enzyme activities measured in treated specimens. Moreover, the mixture induced significant enhancements of DNA fragmentation, which preluded fixed genetic damage, as highlighted by the increase of both apoptotic and micronucleated cells.

The patterns of toxicity and management of acute nonsteroidal anti-inflammatory drug (NSAID) overdose.

The nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for their analgesic, anti-inflammatory and antipyretic actions. They are commonly taken in overdose in many areas of the world. The majority of patients with acute NSAID overdose will remain asymptomatic or develop minor self-limiting gastrointestinal symptoms. However, serious clinical sequelae have been reported in patients with acute NSAID overdose and these include convulsions, metabolic acidosis, coma and acute renal failure. There appear to be some differences between the NSAIDs in terms of the relative risk of these complications; in particular mefenamic acid is most commonly associated with convulsions. The management of these serious clinical features is largely supportive and there are no specific antidotes for acute NSAID toxicity.

Non-surgical treatment of osteoarthritis-related pain in the elderly.

Osteoarthritis (OA), the third most common diagnosis in the elderly [1], causes significant pain leading to disability and decreased quality of life in subjects 65years and older [2]. Traditionally, clinicians have relied heavily on the use of non-steroidal anti-inflammatory drugs (NSAIDs) to treat the pain of OA, as numerous studies have proven these agents to be effective. The cardiovascular, gastrointestinal, renal and hepatic toxicities of NSAIDs have limited their use, particularly in the elderly. Acetaminophen has been recommended as initial therapy due to relative safety. Several other topical, oral and intra-articular agents are available today, with use limited by efficacy and side effect profiles. Many non-pharmacologic approaches are available but underused, and may be attractive choices to avoid poly-pharmacy in older patients. We will attempt to highlight the evidence behind available non-surgical therapies for OA while paying specific attention to issues in geriatric patients.

Comparative Model Studies of Gastric Toxicity of Nonsteroidal Anti-Inflammatory Drugs

A high percentage of people treated with a long-term nonsteroidal anti-inflammatory drug (NSAID) therapy suffer NSAID-induced gastrointestinal-tract-related side effects. A current hypothesis states that the side effects are related to the topical action of NSAID molecules on gastric mucus that lowers its resistance to luminal acid. The main lipids in human mucus are palmitoyloleoylphosphatidylcholine (POPC) and cholesterol (Chol). In this study, both X-ray diffraction and molecular dynamics (MD) simulation methods were employed to investigate the effects of selected NSAIDs in protonated and deprotonated states on the structural parameters of a POPC-Chol bilayer. The drugs were three commonly used NSAIDs with apparently different gastric toxicity: ketoprofen (KET), aspirin (ASP), and piroxicam (PXM). Both methods revealed that the effects of the NSAIDs on the POPC-Chol bilayer parameters were moderate and only slightly differentiated among the drugs. Much larger differences among the drugs were noticed in their interactions with interfacial water and Na(+) as well as with the polar groups of POPC and Chol, mainly via H-bonds. Of the three NSAIDs, KET interacted with POPC and water the most extensively, whereas ASP interacted with Chol and Na(+) more than did the other two. Interactions of PXM with POPC and Chol polar groups as well as with water and Na(+) were limited.

Cardiovascular toxicity of nonsteroidal anti-inflammatory drugs: moving beyond cyclooxygenase selectivity

Cardiovascular toxicity of nonsteroidal anti-inflammatory drugs: moving beyond cyclooxygenase selectivity

Epigallocatechin gallate accelerates healing of indomethacin-induced stomach ulcers in mice

Management of the gastric toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) remains a crucial problem because the commercially available drugs have side effects and are often expensive. Therefore, we examined the potential of the green tea-derived polyphenol epigallocatechin gallate (EGCG) to treat indomethacin-induced stomach ulcers in mice. Administration of indomethacin (18mg/kg, po) to mice induced ulceration in the glandular portion of the gastric mucosa, accompanied by increased lipid peroxidation (LPO) and protein oxidation and reductions in thiol defense, mucin, cyclooxygenase (COX) expression and prostaglandin (PG) synthesis in the gastric tissues. Daily oral administration of EGCG (2mg/kg) or omeprazole (3mg/kg) for 3 days produced similar (~72-75%, p<0.001) beneficial effects on the acute gastric ulceration. Treatment with the test samples partially reversed all the adverse oxidative effects of indomethacin. In addition, EGCG, but not omeprazole, enhanced expression of the COX isoforms and PG synthesis. The results suggest that the non-toxic and inexpensive tea polyphenol EGCG may be an excellent candidate for further evaluation as a potent anti-ulcer drug.

Pain: Not a Normal Part of Aging

Pain: Not a Normal Part of Aging

Effect of indomethacin on bile acid-phospholipid interactions: implication for small intestinal injury induced by nonsteroidal anti-inflammatory drugs.

The injurious effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in the small intestine was not appreciated until the widespread use of capsule endoscopy. Animal studies found that NSAID-induced small intestinal injury depends on the ability of these drugs to be secreted into the bile. Because the individual toxicity of amphiphilic bile acids and NSAIDs directly correlates with their interactions with phospholipid membranes, we propose that the presence of both NSAIDs and bile acids alters their individual physicochemical properties and enhances the disruptive effect on cell membranes and overall cytotoxicity. We utilized in vitro gastric AGS and intestinal IEC-6 cells and found that combinations of bile acid, deoxycholic acid (DC), taurodeoxycholic acid, glycodeoxycholic acid, and the NSAID indomethacin (Indo) significantly increased cell plasma membrane permeability and became more cytotoxic than these agents alone. We confirmed this finding by measuring liposome permeability and intramembrane packing in synthetic model membranes exposed to DC, Indo, or combinations of both agents. By measuring physicochemical parameters, such as fluorescence resonance energy transfer and membrane surface charge, we found that Indo associated with phosphatidylcholine and promoted the molecular aggregation of DC and potential formation of larger and isolated bile acid complexes within either biomembranes or bile acid-lipid mixed micelles, which leads to membrane disruption. In this study, we demonstrated increased cytotoxicity of combinations of bile acid and NSAID and provided a molecular mechanism for the observed toxicity. This mechanism potentially contributes to the NSAID-induced injury in the small bowel.

Assessment and prevention of gastrointestinal toxicity of non-steroidal anti-inflammatory drugs

Abstract Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for analgesic, anti-inflammatory and, in the case of aspirin, for anti-thrombotic actions. The serious gastrointestinal side-effects associated with these drugs are of concern and pose a significant obstacle to their use. This review discusses the pathogenic mechanisms by which the conventional acidic NSAIDs induce gastrointestinal toxicity, with particular emphasis on non-prostaglandin effects. Methods of assessment of NSAID-induced enteropathy are reviewed, with particular emphasis on the use of functional measurement of NSAID-induced changes in the gastrointestinal tract. The advances in our knowledge of the pathogenesis of these effects have resulted in the development of a range of novel NSAIDs. Where functional assessment of the effects of NSAIDs has been employed, it appears to be more useful as an indicator of early-stage changes rather than a predictor of the effects of long-term NSAID exposure. Successful pharmaceutical strategies now offer considerable promise for reducing the severity of NSAID damage to the gastrointestinal tract. The utility of intestinal permeability measurements for selection and assessment of these strategies is discussed.