Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The generation of PGs from arachidonic acid is mediated by cyclooxygenase (COX), which consists of a constitutive (COX-1) and an inducible (COX-2) isoform. The present study evaluated the relative expression and immunoreactive levels of COX-1 and COX-2, by means of RT-PCR, Western blot analysis, and immunohistochemistry, in the renal cortex and medulla of rats with congestive heart failure (CHF), induced by the placement of an aortocaval fistula. In addition, we examined the effects of a COX-1 inhibitor (piroxicam), COX-2 inhibitor (nimesulide), and nonselective COX inhibitor (indomethacin) at a dose of 5 mg/kg, on intrarenal blood flow by laser Doppler flowmetry. COX-1 and COX-2 mRNAs were abundantly expressed in the renal medulla of control and CHF rats and only minimally in the cortex. Moreover, both RT-PCR (32-36 cycles) and Western blot techniques revealed upregulation of medullary COX-2, but not of COX-1, in rats with advanced heart failure. In line with these findings, all three tested COX inhibitors provoked significant and sustained decreases (Delta approximately -20%) in medullary blood flow (MBF), which were similar in magnitude and duration in control animals. However, in CHF rats, indomethacin produced a greater reduction in MBF than that obtained with either piroxicam or nimesulide. Taken together, these results indicate that 1) both COX-1 and COX-2 are predominantly expressed in the renal medulla and 2) experimental CHF is associated with selective overexpression of COX-2. The latter may represent a mechanism aimed at defending MBF in the face of a decrease in renal perfusion pressure during the development of CHF.
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PMID:Intrarenal expression and distribution of cyclooxygenase isoforms in rats with experimental heart failure. 1113 13

Coxibs are a major advance in the therapy of patients with painful and inflammatory conditions. At present, the theoretical harm that derives from inhibiting vascular COX-2 has not emerged as a significant risk, although more research is needed. What has emerged is that some NSAIDs, particularly naproxen, may have an aspirin-like effect in reducing the risk of vascular disease, although more research is needed. Whether this finding is sufficient to recommend naproxen for the management of patients with arthritis who also require vascular protection is intriguing and worth further evaluation. It is widely believed and maintained that coxibs have the greatest potential value in patients with other risk factors for ulcer disease, and this seems likely to be the case for patients taking corticosteroids or anticoagulants and probably those who are elderly. Dosing should be [figure: see text] cautious in old patients, however, because of the ability of NSAIDs and coxibs to cause fluid retention, heart failure, and hypertension. It is less clear that coxibs reduce risk sufficiently in patients with previous ulceration (particularly recent) to make them a better strategy than acid co-therapy. This possibility requires further evaluation, as does the competing value of the 2 strategies for patients infected with H. pylori. If coxibs are used in patients with H. pylori-associated risks, there are grounds to recommend eradication. For patients taking aspirin or drugs [figure: see text] with an aspirin-like effect, the intrinsic risk of these drugs may mandate use of acid suppression and obviate the use of coxibs (Fig. 8). Available data suggest that the risk reduction in patients with no risk factors who use coxibs may be almost as great as in patients with risk factors, with the added advantage that patients may be taken to a state that is virtually free of any risk of ulcer complications that otherwise might require additional therapy. Contrary to current popular truisms, the greatest value of coxibs may be in patients without risk factors because it is in this unconfounded group that the ability of coxibs to free patients of ulcer risk appears to be delivered in full.
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PMID:Gastrointestinal safety of COX-2 specific inhibitors. 1176 35

In the adult mammalian kidney, high levels of cyclooxygenase (COX)-2 expression can be detected in the macula densa and associated cortical thick ascending limb cells and medullary interstitial cells. In the renal cortex, COX-2 expression increases in high renin states, and selective COX-2 inhibitors significantly decrease plasma renin levels. In the medullary region of the kidney, the expression of COX-2 increases in response to a high-salt diet and water deprivation. The most important prostanoids in the kidney are prostaglandin (PG)I(2), or prostacyclin, and PGE(2). PGE(2) diminishes sodium reabsorption; thereby, its inhibition results in sodium retention that can manifest clinically in a variety of ways, such as peripheral edema, increased blood pressure (mainly in treated hypertensive patients), weight gain, and occasionally deterioration of heart failure. PGI(2) increases potassium secretion. As such, its inhibition can result in hyperkalemia, particularly in patients with underlying renal insufficiency. PGI(2) is also a potent vasodilator and helps maintain renal perfusion in conditions of decreased actual or effective circulating volume; its inhibition in such patients can result in acute renal failure. A variety of studies has been conducted to examine the effects of celecoxib and rofecoxib on renal function. These incorporate various study designs directly, making it virtually impossible to compare data across studies. It is apparent from such studies, coupled with published case reports, that the impact of both celecoxib and rofecoxib on renal function (including development of edema and hypertension) is similar to that of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Studies comparing the 2 COX-2 inhibitors conflict in their interpretation. Overall, the data suggest similar effects on renal function among all NSAIDs when used at comparable doses.
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PMID:Cyclooxygenase-2 inhibition and renal physiology. 1190 56

Heart failure constitutes an increasing public health problem because of the growing incidence and prevalence, poor prognosis and high hospital (re)admission rates. Myocardial infarction is the underlying cause in the majority of patients, followed by hypertension, valvular heart disease and idiopathic cardiomyopathy. Nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit the enzymes cyclo-oxygenase (COX) 1 and 2, have been associated with the occurrence of symptoms of heart failure in several case reports and quantitative studies, mainly in patients with a history of cardiovascular disease or left ventricular impairment. NSAIDs may impair renal function in patients with a decreased effective circulating volume by inhibiting prostaglandin synthesis. Consequently, water and sodium retention, and decreases in renal blood flow and glomerular filtration rate may occur, affecting the unstable cardiovascular homeostasis in these patients. In patients with pre-existing heart failure, this may lead to cardiac decompensation. Putative renal-sparing NSAIDs, such as COX-2 selective inhibitors have similar effects on renal function as the traditional NSAIDs, and can likewise be expected to increase the risk of heart failure in susceptible patients. NSAIDs are frequently prescribed to elderly patients, who are particularly at risk for the renal adverse effects. If treatment with NSAIDs in high risk patients cannot be avoided, intensive monitoring and patient education is important.
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PMID:Nonsteroidal anti-inflammatory drugs and heart failure. 1265 51

Our previous work has shown strong expression of COX-2 in the myocardium of patients with end-stage ischemic heart failure. The purpose of this study was to determine the cellular expression of this enzyme in the setting of acute myocardial infarction (AMI) and determine the role of COX-2 in experimental animals using a selective COX-2 inhibitor. Experimental AMI was induced in rats by ligating the left coronary artery. Animals were either treated with a selective COX-2 inhibitor (5 mg x kg(-1) x day(-1)) or vehicle. Three days after ligation, cardiac function was assessed and infarct size was determined. Myocardial specimens were immunostained with antiserum to COX-2. Plasma concentration of prostanoids was measured by enzyme immunoassay. There was strong expression of COX-2 in the myocytes, endocardium, vascular endothelial cells, and macrophages in the infarcted zone of the myocardium. In contrast, little expression was seen in the myocardium of control rats. Animals treated with the COX-2 inhibitor showed a significant improvement in left ventricular (LV) end-diastolic pressure (P < 0.05) and LV systolic pressure (P < 0.01), and a reduction in infarct size (P < 0.05). Inhibition of COX-2 significantly decreased plasma concentration of thromboxane B2 (P < 0.05); however, it did not affect 6-keto-prostaglandin F1alpha. Induction of COX-2 during AMI appears to contribute to myocardial injury, and treatment with the specific inhibitor of the enzyme ameliorated the course of the disease.
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PMID:Cyclooxygenase-2 (COX-2) in acute myocardial infarction: cellular expression and use of selective COX-2 inhibitor. 1271 May 23

The two cyclooxygenase isoforms (COX-1 and COX-2--coxibs) have overlapping functions and both are involved in the regulation of homeostatic and inflammatory processes in the various tissues. Treatment with highly selective COX-2 inhibitors is associated with significantly fewer serious adverse gastrointestinal events than is treatment with the dual inhibitors--the non-selective NSAIDs. Of the two coxibs, rofecoxib was shown to be much more selective than celecoxib and with less interaction with other drugs. Various clinical studies have demonstrated that the coxibs are equivalent, in anti-inflammatory, analgesic and antipyretic efficacy to comparator non-selective NSAIDs in osteoarthritis, rheumatoid arthritis, post surgery pain and dysmenorrhea. Perioperative use of coxibs reduces pain, opioid consumption and the risk of bleeding caused by the non-selective NSAIDs. The coxibs show similar tolerability for renal, liver and cardiothrombotic events as compared to the non-selective NSAIDs. Coxibs are contraindicated in pregnancy, in nursing mothers and pediatric patients and should be used with caution in patients with asthma. The impact of the coxibs on the cardiovascular system is controversial. However, coxibs should be used in caution and at the lowest recommended dose in patients with hypertension, ischemic heart disease and heart failure. These drugs do not interfere with the aspirin anti-platelet aggregation activity. Emerging evidence suggest that the coxibs may also find potential use as supportive therapy in various malignant tumors and intestinal polyps where COX-2 is overly expressed.
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PMID:[Is there a future for COX-2 inhibitors?]. 1560 72

Owing to the selective inhibition of PGI2 synthesis, treatment with COX-2 inhibitors constitutes a potential risk for the increased occurrence of thrombotic cardiovascular incidents and of the first-time occurrence or a deterioration in pre-existing heart failure. Elderly patients, particularly those with a history of ischemic heart disease, hypertension or heart failure, are at risk. One key indication for selective COX-2 inhibitors is the chronic treatment of patients suffering from rheumatoid arthritis or osteoarthritis. However, these patients have an excess cardiovascular mortality, which relates particularly to cardiovascular incidents or heart failure. The use of nonselective antiphlogistic drugs and COX-2 inhibitors is associated with a higher potential risk in these patient groups. In essence, more than 80 million patients worldwide were treated with rofecoxib up to its voluntary withdrawal. The high number of patients who are still being treated with COX-2 inhibitors or for whom the use of COX-2 inhibitors is planned justifies the use of a biochemical marker which, as a screening instrument, is initially designed to recognize the patients who are "ill" despite the lack of symptoms. In asymptomatic patients with NT-proBNP levels below the cut-off, high-risk patients require further work-up. Recognition of these risk factors is easily accomplished considering the case history and the results of an established cardiovascular risk score (e.g. PROCAM score). These risk patients should then also be referred for intensive diagnostic work-up. On the other hand, symptomatic patients or those with high NT-proBNP levels should primarily be referred for more extensive cardiovascular diagnosis before a decision is taken concerning the use of COX-2 inhibitors. As an integral part of this extensive work-up the determination of NT-proBNP can help to improve the accuracy of diagnosis and prognostic assessment. With the exception of patients showing symptoms of an unstable coronary heart disease, imminent cerebral ischemia, uncontrolled arterial hypertension or decompensated heart failure, the use of a COX-2 inhibitor is possible provided special caution is exercised. Termination of treatment is advisable if there is a clinical deterioration of specific symptoms or signs in those patients (product information). Follow-up with NT-proBNP (monitoring) can be helpful in detecting imminent cardiac decompensation at an earlier stage in order to take suitable countermeasures.
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PMID:Rationale for testing the cardiovascular risk for patients with COX-2 inhibitors on the basis of biomarker NT-proBNP. 1571 8

Chronic pain in the elderly is frequently a result of arthritic disorders, particularly osteoarthritis. The cyclo-oxygenase (COX)-2 inhibitors are as effective as standard NSAIDs for the relief of pain and for improving function in elderly patients with osteoarthritis and rheumatoid arthritis. COX-2 inhibitors increase the risk of serious gastroduodenal adverse reactions but there is evidence that they carry a lower risk for these adverse effects than standard NSAIDs, except when there is concurrent aspirin use. Since gastroduodenal disorders are the most frequently reported serious adverse effects of NSAIDs and these disorders occur more frequently in the elderly, COX-2 inhibitors offer an alternative to standard NSAIDs in this age group. However, they are not appropriate for many patients with cardiovascular and renal disease. The adverse reaction profile of the COX-2 inhibitors has confirmed the role of the COX-2 enzyme in renal function, salt and water homeostasis and the vascular endothelium. Thus, like standard NSAIDs, COX-2 inhibitors can cause renal failure, hypertension and exacerbation of cardiac failure. Of note is that these disorders are dose related. Thus, there are good reasons to avoid high doses of COX-2 inhibitors in the elderly. Clinical trials indicate that daily doses of rofecoxib 12.5 mg, celecoxib 100-200 mg, valdecoxib 10mg and etoricoxib 60 mg are the minimum effective doses of these agents. Data from the New Zealand Intensive Medicines Monitoring Programme indicate that celecoxib 200 mg/day and rofecoxib 25 mg/day are/were the most commonly prescribed doses and that 6% of patients had taken rofecoxib 50 mg/day for longer than recommended. Recent research indicates that COX-2 inhibitors have a thrombotic potential, especially in high doses and when use is prolonged, and this further limits the extent to which they can be used in the elderly. Important interactions with COX-2 inhibitors in the elderly include those with warfarin, which can result in loss of control of anticoagulation, and those with ACE inhibitors, angiotensin II type 1 receptor antagonists and diuretics, which can result in loss of control of blood pressure and cardiac failure and, in hypovolaemic conditions, renal failure. The clinical significance of an interaction between celecoxib and aspirin to reduce the antiplatelet effect of the latter drug is unknown. Preliminary information from spontaneous reporting systems indicates that there may be differences in the risk of cardiac failure and hypertension between standard NSAIDs and COX-2 inhibitors and between rofecoxib and celecoxib. More formal studies using equivalent doses are needed to test this observation. Use of COX-2 inhibitors may be considered in the elderly to reduce the risk of gastroduodenal complications associated with standard NSAIDs but only when consideration has first been given to use of less toxic medicines as alternatives or supplements, the appropriate dose of the COX-2 inhibitor or standard NSAID, the presence and possible impact of co-morbidities, and the implications of taking COX-2 inhibitors with any concomitant medications. Equally important is regular monitoring of the patient taking a COX-2 inhibitor for efficacy and adverse effects, and ensuring that the patient has a continuing need to keep taking the drug. Close attention also needs to be paid to intercurrent illnesses and new prescriptions that may reduce the safety of the COX-2 inhibitor. A standard NSAID plus a proton pump inhibitor may be equally effective as a COX-2 inhibitor in reducing the risk of gastroduodenal toxicity and if used the same prescribing advice applies. Current knowledge concerning the thrombotic potential of COX-2 inhibitors suggests that this combination, if tolerated, may be preferable to a COX-2 inhibitor, particularly where prolonged use is required. This knowledge also indicates that for patients with or at high risk of ischaemic heart disease or stroke, COX-2 inhibitors are contraindicated.
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PMID:Cyclo-oxygenase-2 inhibitors: when should they be used in the elderly? 1581 52

Since, their introduction, COX (cyclooxygenase enzyme)-2 specific inhibitors have become a rapidly growing segment of the prescription drug market. Researchers have recently focused on the potentially lethal side effects associated with their. FDA has banned the use of nimesulide (hepatotoxic) in pediatric patients and rofecoxib (cardiovascular complications) in both adults and children. COX-2 inhibitors may decrease vascular prostacyclin production and may tip the balance in favour of prothrombotic eicosanoids (thromboxane A2) and lead to increased cardiovascular thrombotic events. COX-2 inhibitors can also result into increase blood pressure, macular eruptions, urticaria, pseudoporphyria, erythema multiforme, oedema, worsening of heart failure, fatal allergic vasculitis and aggravation of doxorubicin-mediated cardiac injury. The COX-2 enzyme is also involved in the development of many organ systems, and its inhibition may lead to various congenital defects in neonates. It has been reported that COX-2 inhibitors also interfere with implantation, hence their use should be avoided in sexually active women at risk of pregnancy. However, presently the choice of COX-2 selective inhibitors for a particular patient should be based upon their relative efficacy, toxicity, concomitant drug use, concurrent disease states, hepatic and renal function and relative cost.
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PMID:COX-2 selective nonsteroidal anti-inflammatory drugs: current status. 1592 4

Heart failure (HF) is a multifactorial and progressive disease that has been associated with multiple systemic and vascular alterations. Previous reports from our laboratory showed that in 2-month-old Bio-To2 Syrian cardiomyopathic hamsters (SCH) that have not yet developed the clinical manifestations of HF, the vascular contractility induced by 0.1 microM angiotensin II was approximately 35% greater than in control animals. This finding was observed concomitantly with an increased aortic ACE activity. To further evaluate the mechanisms underlying angiotensin II-enhanced vascular contraction, concentration-response curves for angiotensin II (0.01 nM-10 microM) were constructed before and after the addition of prazosin (alpha-1 blocker), NS-398 (selective COX-2 blocker) and BQ-123 (ET-1A-receptor antagonist) in aortic rings from 2-month-old SCH. The binding capacity and affinity of the AT-1 receptors were also evaluated in aortic homogenates using 125I-angiotensin II. Age-matched golden hamsters were used as controls (CT). Our results indicate that incubation with either 10 microM prazosin or 10 microM NS-398 did not modify EC50 or Emax values for angiotensin II indicating that norepinephrine and prostaglandins are not involved in the enhanced contractile action of angiotensin II. However, 10 microM BQ-123 reduced by 40% the contraction induced by 1.0 microM angiotensin II (from 1.05+/-0.04 to 0.6475+/-0.06 g/mg tissue, n = 5, P < 0.05), suggesting that in cardiomyopathic hamsters, the action of angiotensin II is mediated in part by ET-1. At lower angiotensin II concentration (0.1 microM), the ET-1-dependent contraction decreases to 29%. In addition, although dissociation constants for labeled angiotensin II were found to be similar in the aorta of SCH and control animals (K(D): CT = 7.8 nM and SCH = 5.1 nM), 125I-angiotensin II binding capacity was about 2-fold greater in SCH than in controls (Bmax: SCH = 1113 and CT = 605 fmol/mg protein). Altogether these results suggest that in 2-month-old SCH the enhanced response of angiotensin II in the vasculature is mediated both by an increased binding capacity for the hormone and facilitation of the ET-1 action.
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PMID:Increased vascular angiotensin II binding capacity and ET-1 release in young cardiomyopathic hamsters. 1650 5


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