Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aspirin was developed as a non-steroidal anti-inflammatory drug (NSAID) in 1899. During the century after that, aspirin has been found to show its anti-inflammatory, analgesic and anti-pyretic activities by reducing prostaglandins biosynthesis through inhibition of cyclooxygenase (COX); and then COX was found to be constituted of two isoforms, constitutive COX-1 and inducible COX-2. Currently, novel NSAIDs, acting through selective inhibition of COX-2, that have efficacy as excellent as aspirin with significantly lower incidence of gastrointestinal adverse effects are available in America and some other countries, but not in Japan. Physiological and pathophysiological roles of COX-1 and COX-2 have been explained from studies in experimental animals, but there are many differences in species and diseases between animals and humans. Thus, physiological and pathophysiological roles of COX-2 were considered from the standpoint of clinical effects of the two latest COX-2 selective inhibitors, celecoxib and rofecoxib, on inflammation, pain, fever and colorectal cancer together with their adverse effects on gastrointestinal, renal and platelet functions; and the usefulness and limits of COX-2-selective inhibitors were discussed with the trends of new NSAIDs development.
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PMID:[Cyclooxygenase (COX)-2 selective inhibitors: aspirin, a dual COX-1/COX-2 inhibitor, to COX-2 selective inhibitors]. 1157 63

Tumor growth and angiogenesis are interdependent. Cyclooxygenase (COX) catalyzes the synthesis of prostaglandins from arachidonic acid. Nonsteroidal antiinflammatory drugs (NSAIDs) inhibit COX-mediated synthesis of prostaglandins. COX-1 is constitutively expressed in a wide range of tissues, whereas COX-2 is cytokine inducible. Enhanced COX-2 expression has been attributed a key role in the development of inflammation and related processes observed in pathologically altered disease states. Two specific COX-2 inhibitors, namely rofecoxib (Vioxx) and celecoxib (Celebrex), both oral agents and U.S. Food and Drug Administration approved, have been shown preclinically and clinically to have efficacy comparable to that of NSAIDs for relief of pain and inflammation in osteoarthritis, with decreased risk of gastrointestinal damage. Little is known about how angiogenesis is affected by the combination of rofecoxib and radiation. We have evaluated the combination of rofecoxib, at various concentrations, and radiation on cytokine-induced angiogenesis in vitro. We have found that rofecoxib inhibited endothelial cell proliferation, migration, and tube formation (differentiation) at clinically relevant doses. In combination with radiation, inhibition of endothelial cell function further increased twofold. The combination of rofecoxib and radiation suggests a complementary strategy with clinical ramifications to target angiogenesis-dependent malignancies.
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PMID:Targeting angiogenic processes by combination rofecoxib and ionizing radiation. 1158 92

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely prescribed drugs worldwide owing to their anti-inflammatory, antipyretic and analgesic properties. However, their use is hampered by gastrointestinal (GI) toxicity, the most common drug-related serious adverse event in industrialised nations. Nitric oxide (NO)-releasing NSAIDs, a recently described class of drugs, are generated by adding a nitroxybutyl or a nitrosothiol moiety to the parent NSAID via a short-chain ester linkage. While efficacy of nitrosothiol-NO-NSAIDs still awaits investigation, nitroxybutyl-NO-NSAIDs have been extensively studied in animals, thus the abbreviation NO-NSAIDs used here refers to the latter group of NSAID derivatives. NO-NSAIDs retain the anti-inflammatory and antipyretic activity of original NSAIDs, although they exhibit markedly reduced gastrointestinal toxicity. NO-NSAIDs are nonselective cyclo-oxygenase (COX) inhibitors, and they also exert COX-independent activities that are NO-dependent. Indeed, NO-NSAIDs suppress production of the cytokines interleukin (IL)-1beta, IL-18 and interferon-gamma by causing the S-nitrosilation/inhibition of caspase-1. In acute and chronic animal models of inflammation, it has been demonstrated that NO-NSAIDs abrogated prostaglandin E2 as well as thromboxane B2 generation. In a murine model, NO-naproxen was approximately 10-fold more potent than naproxen in reducing animal writhing after intraperitoneal injection of acetic acid. Similar data have been obtained in chronic models of pain such as rat adjuvant arthritis. In vivo and in vitro studies suggest that NO-aspirin (acetylsalicylic acid) exerts more potent antithrombotic action than aspirin, probably by coupling the ability to inhibit COX-1 with the anti-adhesive effect of NO. Moreover, in a model of renal injury NO-flurbiprofen not only has been demonstrated to be devoid of nephrotoxicity but also to ameliorate renal function. Finally, in an animal model of chronic neurodegenerative disease, NO-flurbiprofen and NO-aspirin attenuated the brain inflammatory response. The GI toxicity of NO-flurbiprofen and NO-naproxen is currently being investigated in healthy individuals.
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PMID:Nitric oxide-releasing NSAIDs: a review of their current status. 1166 68

While non-steroidal anti-inflammatory drugs (NSAIDs) are the mainstay of therapy for the management of acute pain and rheumatoid arthritis, toxicity associated with chronic administration limits their benefit-to-risk relationship in many patients. A series of studies is reviewed that assesses the relationship between cytokines released at the site of tissue injury and NSAID analgesia, and the in vivo selectivity of a selective cyclooxygenase (COX)-2 inhibitor (celecoxib) in comparison to a dual COX-1/COX-2 inhibitor (ketorolac). Three replicate studies in the oral surgery model of acute pain used submucosal microdialysis sample collection for the measurement of prostaglandin E2 (PGE2; a product of both COX-1 and COX-2) and thromboxane B2 (as a biomarker for COX-1 activity) with parallel assessments of pain. The time course of PGE2 production was consistent with early release due to COX-1 activity followed by increased production 2-3 hours after surgery, consistent with COX-2 expression. Ketorolac 30 mg at pain onset suppressed both pain and peripheral PGE2 levels. Ketorolac 1 mg either at the site of injury or intramuscularly also produced analgesia but without any effect on peripheral PGE2 levels. Celecoxib selectively suppressed PGE2 but not TxB2 at time points consistent with COX-2 activity, while producing analgesia. These studies demonstrate the ability to assess the time course and selective effects of COX-2 inhibitors in vivo and suggest that suppression of COX-2 mediated PGE2 is temporally related to NSAID analgesia.
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PMID:Analgesia and COX-2 inhibition. 1169 55

Rheumatic diseases are the most prevalent causes of disability in western countries, and non-steroidal anti-inflammatory drugs (NSAIDs) are still the most commonly used remedies. However, NSAIDs cause several serious adverse effects, the most important being from gastric injury to gastric ulceration and renal damage. Attempts to develop non-steroidal anti-inflammatory remedies devoid of these shortcomings-especially gastrointestinal toxicity-have followed several strategies. Non-steroidal anti-inflammatory drugs have, therefore, been associated with gastroprotective agents that counteract the damaging effects of prostaglandin synthesis suppression; however, a combination therapy introduces other problems of pharmacokinetics, toxicity, and patient's compliance. More recently, incorporation of a nitric oxide (NO)-generating moiety into the molecule of several NSAIDs was shown to greatly attenuate their ulcerogenic activity; however, several findings suggest a possible involvement of NO in the pathogenesis of arthritis and subsequent tissue destruction. A most promising approach seemed to be the preparation of novel NSAIDs, targeted at the inducible isoform of prostaglandin synthase (COX-2); they appear to be devoid of gastrointestinal toxicity, in that they spare mucosal prostaglandin synthesis. However, a number of recent studies have raised serious questions about the two central tenets that support this approach, namely that the prostaglandins that mediate inflammation and pain are produced solely via COX-2 and that the prostaglandins that are important in gastrointestinal and renal function are produced solely via COX-1. So, a growing body of evidence shows that COX-2 (not only COX-1) also plays a physiological role in several body functions and that, conversely, COX-1 (not only COX-2) may also be induced at sites of inflammation. More recent and puzzling data shows that COX-2 is induced during the resolution of an inflammatory response, and at this point it produces anti-inflammatory (PGD2 and PGF2alpha), but not proinflammatory (PGE2) prostaglandins; inhibition of COX-2 at this point thus results in persistence of the inflammation. Moreover, COX-2 selective NSAIDs have lost the cardiovascular protective effects of non-selective NSAIDs, effects which are mediated through COX-1 inhibition (in addition, COX-2 has a role in sustaining vascular prostacyclin production). The generation of other very important products of the arachidonic acid cascade (besides cyclooxygenase-produced metabolites) is inhibited neither by non-selective nor by COX-2 selective NSAIDs. The products generated by the 5-lipoxygenase pathway (leukotrienes) are particularly important in inflammation; indeed, leukotrienes increase microvascular permeability and are potent chemotactic agents. Moreover, inhibition of 5-lipoxygenase indirectly reduces the expression of TNF-alpha (a cytokine that plays a key role in inflammation). These data and considerations explain the efforts to obtain drugs able to inhibit both 5-lipoxygenase and cyclooxygenases, the so-called dual acting anti-inflammatory drugs. Such compounds retain the activity of classical NSAIDs, while avoiding their main drawbacks, in that curtailed production of gastroprotective prostaglandins is associated with a concurrent curtailed production of the gastro-damaging and bronchoconstrictive leukotrienes. Moreover, thanks to their mechanism of action, dual acting anti-inflammatory drugs could not merely alleviate symptoms of rheumatic diseases, but might also satisfy, at least in part, the criteria of a more definitive treatment. Indeed, leukotrienes are pro-inflammatory, increase microvascular permeability, are potent chemotactic agents and attract eosinophils, neutrophils and monocytes into the synovium.
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PMID:Dual acting anti-inflammatory drugs: a reappraisal. 1173 48

Aspirin and the nonsteroidal anti-inflammatory drugs (NSAIDs) have been commercially available for decades, and their ability to reduce pain and inflammation are well known. The ability of these agents to cause adverse effects are also known, and the search for newer NSAIDs with less side effects accelerated after the two isoforms of cyclooxygenase (COX) (COX-1 and COX-2) were discovered. The selective COX-2 inhibitors seem to have equivalent efficacy, but potentially less gastrointestinal adverse effects than the traditional NSAIDs. Recent concern that the selective COX-2 inhibitors could increase cardiovascular events requires more investigation. In the meantime, aspirin continues to receive attention as a potential primary cardiovascular agent because of its antiplatelet effects and past and current clinical trials. Several trials have demonstrated that low-dose aspirin may significantly reduce the risk of myocardial infarction and other cardiovascular events. However, the benefits of aspirin need to be weighed against its primary side effect in these situations (hemorrhagic stroke). Patients at low risk for future cardiovascular events are probably not good candidates for this therapy; however, those individuals with a high risk of a future cardiovascular event may qualify for this therapy. Aspirin has also demonstrated a potential ability to reduce the risk of deep venous thrombosis and pulmonary embolism. A recent large trial of low-dose aspirin after major surgery revealed that this agent could also have some activity in the venous component of the human body. Aspirin may also have some applicability for reducing side effects of oral estrogens in men with advanced prostate cancer. Thus, it seems as if aspirin, NSAIDS, and even the selective COX-2 inhibitors may have therapeutic potential far beyond reducing pain and general inflammation. These overall observations and effects provided some of the impetus to investigate their potential ability to reduce the risk and possibly progression of a number of cancers. A few already available over-the-counter products and prescriptions seem to be receiving attention as possible anticancer agents.
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PMID:An introduction to aspirin, NSAIDs, and COX-2 inhibitors for the primary prevention of cardiovascular events and cancer and their potential preventive role in bladder carcinogenesis: part I. 1176 81

Two cyclooxygenase (COX) isoforms have been identified: COX-1 and COX-2. COX-1 is the constitutively expressed form of the enzyme and is ubiquitous in its distribution. COX-2 is inducible and is present in inflammatory foci, tumors, and neovasculature. Expression of COX-2 appears to be important in tumor promotion, growth, and metastasis. It is up-regulated in a variety of premalignant disorders and malignancies. COX inhibitors have a major role in the treatment of inflammation and pain. Epidemiologic evidence in patients who take nonsteroidal anti-inflammatory drugs links COX inhibition with decreases in malignant esophageal, stomach, colon, lung, and breast tumors. Nonselective COX inhibitors have demonstrated efficacy in control of familial adenomatous polyposis, a disorder associated with the development of thousands of benign intestinal polyps. The selective COX-2 inhibitor celecoxib (Celebrex, Pharmacia) has been shown to reduce the number of adenomatous colorectal polyps in familial adenomatous polyposis as an adjunct to usual care. Celecoxib has recently been approved for this indication and offers the potential for equivalent or greater efficacy than that seen with nonselective COX inhibitors but without the gastrointestinal mucosal toxicity and the inhibition of platelet function associated with those agents. Angiogenesis is a feature of both benign and malignant disease. Because COX-2 is up-regulated in the neovasculature of the rheumatoid pannus and in malignant tumors and their surrounding stroma, selective COX-2 inhibitors may be able to modify the progression of these disorders through the control of angiogenesis.
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PMID:Approach to angiogenesis inhibition based on cyclooxygenase-2. 1177 86

Osteoarthritis (OA) is responsible for more disability of the lower extremities in the elderly than any other disease in the US. The pain associated with OA is the primary symptom leading to disability in these patients. Current ACR guidelines recommend consideration of acetaminophen for mild-to-moderate pain and conventional non-steroidal anti-inflammatory drugs (NSAIDs) or COX-2 specific inhibitors for moderate-to-severe OA symptoms. The aim of this study was to compare the efficacy and safety of the COX-1 sparing, COX-2 specific inhibitor, celecoxib, with the conventional NSAID naproxen, and placebo, in the treatment of OA of the hip. In this multicenter, randomized, placebo-controlled trial, 1061 patients with symptomatic OA of the hip were randomized to receive celecoxib at doses of 100 mg, 200 mg, or 400 mg/day; naproxen 1000 mg/day; or placebo, for 12 weeks. Patients were evaluated using standard measures of efficacy at baseline, 2-4 days after discontinuing previous NSAID or analgesic therapy, and after 2, 6, and 12 weeks of treatment. All doses of celecoxib and naproxen significantly improved the symptoms of OA, at all time points compared with placebo. This sustained treatment effect of celecoxib was dose dependent. In terms of pain relief and improvement in functional capacity, celecoxib 200 mg/day and 400 mg/day were similarly efficacious and were comparable to naproxen. Both drugs were generally well tolerated. Celecoxib at a dose of 200 mg/day is as effective as a standard therapeutic dose of the conventional NSAID, naproxen, in reducing the pain associated with OA of the hip.
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PMID:Comparative efficacy and safety of celecoxib and naproxen in the treatment of osteoarthritis of the hip. 1180 30

The enzyme cyclooxygenase (COX) catalyzes the first step of the synthesis of prostanoids. In the early 1990s, COX was demonstrated to exist as two distinct isoforms. COX-1 is constitutively expressed as a "housekeeping" enzyme in most tissues. By contrast, COX-2 can be up-regulated by various pro-inflammatory agents, including lipopolysaccharide, cytokines, and growth factors. Whereas many of the side effects of nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., gastrointestinal ulceration and bleeding, platelet dysfunctions) are caused by a suppression of COX-1 activity, inhibition of COX-2-derived prostanoids facilitates the anti-inflammatory, analgesic, and antipyretic effects of NSAIDs. During the past few years specific inhibitors of the COX-2 enzyme have emerged as important pharmacological tools for treatment of pain and arthritis. However, although COX-2 was initially regarded as a source of pathological prostanoids only, recent studies have indicated that this isoenzyme mediates a variety of physiological responses within the organism. The present review assesses recent advances in COX-2 research, with particular emphasis on new insights into pathophysiological and physiological functions of this isoenzyme.
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PMID:Cyclooxygenase-2--10 years later. 1180 93

Intrathecal phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2), but not COX-1, inhibitors attenuate facilitated pain states generated by peripheral injury/inflammation and by direct activation of spinal glutamate and substance P receptors. These results are consistent with the constitutive expression of PLA2 and COX-2 in spinal cord, the spinal release of prostaglandins by persistent afferent input, and the effects of prostaglandins on spinal excitability. Whereas the acute actions of COX-2 inhibitors are clearly mediated by constitutively expressed spinal COX-2, studies of spinal COX-2 expression indicate that it is upregulated by neural input and circulating cytokines. Given the intrathecal potency of COX-2 inhibitors, the comparable efficacy of intrathecal versus systemic COX-2 inhibitors in hyperalgesic states not associated with inflammation, and the onset of antihyperalgesic activity prior to COX-2 upregulation, it is argued that a principal antihyperalgesic mechanism of COX-2 inhibitors lies with modulation of constitutive COX-2 present at the spinal level.
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PMID:The spinal phospholipase-cyclooxygenase-prostanoid cascade in nociceptive processing. 1180 83


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