Cyclooxygenase-2--specific inhibitors and cardiorenal function: a randomized, controlled trial of celecoxib and rofecoxib in older hypertensive osteoarthritis patients

Current pharmacotherapy for the treatment of severe burns

The pharmacotherapy of burn care has evolved from the first topical antibiotics instituted > 30 years ago. These have helped greatly to reduce the incidence of burn wound sepsis, but a better understanding of the principles of burn care has resulted in earlier burn wound excision and complete coverage with autograft, cadaver skin, synthetic dressings, and amnion. This has markedly reduced septic complications and ameliorated the hypermetabolic response to burn injury. The hypermetabolic response, which is mediated by hugely increased levels of circulating catecholamines, prostaglandins, glucagon and cortisol, causes profound skeletal muscle catabolism, immune deficiency, peripheral lipolysis, reduced bone mineralisation, reduced linear growth, and increased energy expenditure. Supportive therapy and pharmacological manipulation, acutely and during rehabilitation, with growth hormone, insulin and related proteins, oxandrolone and propranolol can ameliorate the hypermetabolic response, improving survival and long-term outcome. Despite judicious use of topical and systemic antibiotics, opportunistic nosocomial bacterial resistance threatens to annul the improved survival of patients with severe burns. Patterns of emerging resistance encountered in burn units need to be considered, in light of a decreasing antibiotic armamentarium. A holistic approach to pharmacotherapy of severely burned patients including current practice in antimicrobial control, analgesia, sedation, and anxiety management is required. Current therapy of frequently encountered problems, such as post-burn pruritus, prophylaxis of deep venous thrombosis and peptic ulceration, and pharmacological manipulation of inhalation injury in the burned patient is described. Current pharmacotherapy to ameliorate psychosocial problems associated with burns such as acute stress disorder, depression and post traumatic stress disorder are discussed. Better analgesics, newer antibiotics and immune stimulating drugs are required to reduce mortality and morbidity in large burns.

Opioid and non-opioid analgesics

Opioids are the most potent analgesics. Toxicity results either from effects mediated by variation in affinity and intrinsic efficacy at specific opioid receptors or, rarely, from a direct toxic effect of the drugs. For some adverse effects, opioids exhibit a 'dual pharmacology' whereby these effects are usually observed only in pain-free individuals, and are not seen in patients in pain. Paracetamol, although generally very safe in therapeutic doses, displays potentially fatal toxicity in overdose requiring specific treatment. Non-steroidal anti-inflammatory drugs (NSAIDs) are known to act by inhibiting COX-1 and COX-2 isoenzymes to various degrees. Toxicity arises primarily from undesired inhibition at these enzyme sites. Knowledge of the mechanism of action of these drugs is fundamental to the understanding of their potential for toxicity, the details of which are still emerging.

Opposite effects of rofecoxib on nuclear factor-kappaB and activating protein-1 activation

Rofecoxib is a selective cyclooxygenase (COX)-2 inhibitor approved for the treatment of pain and inflammation in rheumatoid and osteoarthritis. Daily doses between 12.5 and 50 mg were found to reduce pain and inflammation, however, without a clear dose-effect relationship. Interestingly, rofecoxib treatment is associated with an unexpected incidence of renal adverse events compared with other COX inhibitors. Here, the effects of rofecoxib on the transcription factors nuclear factor-kappaB (NF-kappaB) and activating protein-1 (AP-1) were analyzed to find out whether transcriptional changes might explain the lack of clear dose dependency and the occurrence of renal side effects. In vitro, rofecoxib dose dependently inhibited DNA binding capacity of NF-kappaB at doses of 10 to 100 microM, whereas the binding activity of AP-1 was considerably increased at 100 microM. In vivo, the anti-inflammatory effect of rofecoxib was equal at 1 and 10 mg/kg, whereas 50 mg/kg caused a significant further reduction of a zymosan-induced paw edema. This was associated with a clear decrease of inducible nitric oxide synthase (iNOS) protein expression in the spinal cord at this dose. At 1 and 10 mg/kg, however, iNOS was increased but COX-2 was decreased. Thus, the expression of proinflammatory proteins was similarly inconsistent as transcription factor regulation. In conclusion, the opposite effects of rofecoxib on AP-1 and NF-kappaB may explain the lack of clear dose dependency with rofecoxib in clinical studies or animal experiments. The effects on AP-1 may possibly affect renal sodium transport because certain renal sodium channels are regulated through AP-1. Transcription factor regulation might therefore influence both wanted and unwanted effects of rofecoxib.

[Clinical trials with rofecoxib: analysis of the information from the gender perspective]

BACKGROUND AND OBJECTIVE

There is evidence if the low rate of participation or even exclusion of women in clinical trials (CT), and that sex-differences are not considered in the design and analysis of the CT. The objectives of the study were to determine whether women are properly represented in the CT with rofecoxib and to analyze the information of CT with rofecoxib from a gender perspective.

MATERIAL AND METHOD

Twenty eight rofecoxib CT in adults have been reviewed, all indexed in Medline and published between 1999-2001. The FDA Guideline for the Study and Evaluation of Gender Differences in the Clinical Evaluation Drugs was used to analyze the information.

RESULTS

An 80% of the trials do not describe efficacy results by sex, and only one reports side effects by sex. A 78.3% does not report stratified analysis by sex. In the discussion the possible difference by sex of the results is mentioned in 3 occasions. Only 8% of the CT considers the influence of hormonal variation in the results. The pharmacokinetics issues related specifically to women are poorly followed: in 60% of the CT it is not specified the influence of oral contraceptives in the results of the trial, and in 88.9% of CT it is not specified the influence of estrogen treatment in the results of the trial. Pregnancy as exclusion criteria is only considered in 50% of the trials.

CONCLUSIONS

CT with rofecoxib has included more women than men. Important information on specific situation related to gender, recommends by FDA Guideline for the Study and Evaluation of Gender Differences in the Clinical Evaluation Drugs, have not been followed.

Review article: NSAIDs, gastroprotection and cyclo-oxygenase-II-selective inhibitors

In patients at high risk of NSAID-associated serious upper gastrointestinal complications, gastroprotection with misoprostol or a proton pump inhibitor should be considered. Only misoprostol, 800 micro g/day, has been shown to reduce serious upper gastrointestinal complications in a large clinical outcome trial. The benefit of Helicobacter pylori eradication in reducing NSAID-associated gastrointestinal toxicity is controversial, and routine testing for and eradication of H. pylori in NSAID users are not currently advised. The gastrointestinal safety of rofecoxib and celecoxib has been assessed in large clinical outcome trials which, on first analysis, show benefits over non-selective NSAIDs in the incidence of serious upper gastrointestinal complications. However, longer term gastrointestinal data from the celecoxib study (CLASS) and cardiovascular adverse event data from the rofecoxib study (VIGOR) have questioned the risk-benefit profile of these new drugs and, until they are better understood, it seems sensible not to use them routinely in large numbers of individuals. The gastrointestinal safety of meloxicam and etodolac has not been adequately assessed in such trials. Therefore, evidence for their use instead of non-selective NSAIDs, or instead of celecoxib or rofecoxib, is not robust.

Coxibs--beyond the GI tract: renal and cardiovascular issues

Although the coxibs have demonstrated superior gastrointestinal safety compared to traditional non-selective NSAIDs, questions remain regarding their effects on the renal and cardiovascular systems. In terms of renal function, both Type 1 and Type 2 cyclooxygenase (COX-1 and COX-2) are expressed constitutively in the kidney. Prostaglandins do not play a major role in the maintenance of renal function in healthy individuals but they become profoundly important in certain clinical situations such as renal stress, or volume depletion. In such situations the effects of the coxibs and non-selective NSAIDs are likely to be similar. The incidence of renal side effects is low (1-5%) and the patients at risk of renal complications are well defined and can usually be identified prospectively and followed up as appropriate. From the cardiovascular point of view, questions have been raised as to whether the coxibs have a prothrombotic effect. Here we review the available evidence and consider various hypotheses for an apparent increase in cardiovascular events reported in one coxib study (the VIGOR trial). Because of a lack of anti-platelet activity, coxibs are not suited for the provision of cardiovascular prophylaxis, and in patients at risk of myocardial infarction the prophylactic use of aspirin should always be considered. Although evidence suggests that use of coxibs with low-dose aspirin is safer than the combination of traditional NSAIDs with aspirin, further studies are required to confirm that this is the case.

A model analysis of costs of blood pressure destabilization and edema associated with rofecoxib and celecoxib among older patients with osteoarthritis and hypertension in a Medicare Choice population

BACKGROUND

Economic analyses consider all costs relevant to the use of a particular treatment or treatments. Recently, head-to-head, randomized, controlled trials have shown a significantly higher incidence of blood pressure (BP) destabilization and clinically significant edema with rofecoxib than with celecoxib among older, hypertensive patients with osteoarthritis (OA).

OBJECTIVE

The objective of this analysis was to estimate the COX-2 specific inhibitor medication costs, in addition to the costs of drugs and physicians' fees, for BP destabilization and clinically significant edema associated with the use of rofecoxib 25 mg QD and celecoxib 200 mg QD in patients with OA and hypertension in a Medicare Choice population (aged > or = 65 years).

METHODS

A decision analysis model was constructed to determine the costs (from the payer's perspective) of treating patients in this population with either of the 2 regimens for 6 weeks. The analysis used pooled data from 2 recent, independently conducted, multicenter, double-blind, randomized, controlled trials of OA patients aged > or = 65 years with treated hypertension who received either celecoxib 200 mg QD or rofecoxib 25 mg QD for 6 weeks. In the individual trials, rofecoxib was associated with significantly higher rates of destabilized BP (P < 0.032 and P < 0.001) and edema (P < 0.01 and P = 0.045) than celecoxib.

RESULTS

For a 100,000-member Medicare Choice population, an estimated 25,630 persons would have OA and hypertension (stages I-III), and an estimated 5126 of these patients would use celecoxib or rofecoxib. The estimated costs were 33,938 dollars (6.2%) higher if all hypertensive patients with OA were treated with rofecoxib rather than celecoxib for 6 weeks. The cost per day of use was 0.16 dollars less with celecoxib, and per-patient, per-month costs were 4.79 dollars lower.

CONCLUSION

Celecoxib was a less costly treatment option than rofecoxib among OA patients with hypertension aged > or = 65 years, based on our model of the direct costs of COX-2 specific inhibitor therapy combined with those associated with physician monitoring and treatment of edema and BP destabilization.

Comparison of low-dose rofecoxib versus 1000 mg naproxen in patients with osteoarthritis. Results of two randomized treatment trials of six weeks duration

OBJECTIVE

To compare the efficacy and safety of rofecoxib 12.5 mg once daily to naproxen 500 mg twice daily in patients > or = 40 years of age with knee or hip osteoarthritis (OA).

METHOD

Two identical 6-week, randomized, double-blind studies were conducted (1 in Africa, Australia, Europe, Canada, Mexico, & South America; 1 in Asia). Primary endpoints were pain walking on a flat surface, patient global assessment of response to therapy, and investigator global assessment of disease status.

RESULTS

Overall, 944 patients participated. For all efficacy endpoints, treatment effects for rofecoxib and naproxen were comparable and seen at the first measures of efficacy. Both compounds were generally well-tolerated, with an improved gastrointestinal safety profile for rofecoxib versus naproxen. CONCLUSIONS In these studies, rofecoxib 12.5 mg once daily (the lowest indicated dose) and naproxen 500 mg twice daily showed similar treatment effects in OA patients. Rofecoxib and naproxen were generally well tolerated.

Effects of celecoxib and rofecoxib on blood pressure and edema in patients > or =65 years of age with systemic hypertension and osteoarthritis

Concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs), including the cyclooxygenase-2 (COX-2) specific inhibitors, with antihypertensive medication is common practice for many patients with arthritis. This study evaluated the effects of celecoxib 200 mg/day and rofecoxib 25 mg/day on blood pressure (BP) and edema in a 6-week, randomized, parallel-group, double-blind study in patients > or =65 years of age with osteoarthritis who were treated with fixed antihypertensive regimens. One thousand ninety-two patients received study medication (celecoxib, n = 549; rofecoxib, n = 543). Significantly more patients in the rofecoxib group compared with the celecoxib group developed increased systolic BP (change >20 mm Hg plus absolute value > or =140 mm Hg) at any time point (14.9% vs 6.9%, p <0.01). Rofecoxib caused the greatest increase in systolic BP in patients receiving angiotensin-converting enzyme inhibitors or beta blockers, whereas those on calcium channel antagonists or diuretic monotherapy receiving either celecoxib or rofecoxib showed no significant increases in BP. Clinically significant new-onset or worsening edema associated with weight gain developed in a greater percentage of patients in the rofecoxib group (7.7%) compared with the celecoxib group (4.7%) (p <0.05). Thus, in patients with controlled hypertension on a fixed antihypertensive regimen, careful monitoring of BP is warranted after the initiation of celecoxib or rofecoxib therapy.

The Renal Effects of Traditional Nonsteroidal Anti-Inflammatory Agents Versus Cyclooxygenase-2 Inhibitors

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the management of acute and chronic pain as well as for rheumatoid arthritis and osteoarthritis. Although gastrointestinal complications are the most common adverse events associated with the use of these drugs, the renal adverse effects such as acute renal failure, electrolyte abnormalities, nephrotic syndrome, interstitial nephritis, and papillary necrosis can be serious. The cyclooxygenase-2 (COX-2)- selective NSAIDs (celecoxib, rofecoxib) have been associated with a reduced frequency of gastrointestinal adverse events, but questions still remain as to their renal safety. Recent information has suggested an increased role for COX-2 as a constitutive renal enzyme, thus implying its importance for normal kidney homeostasis. Clinical studies and published case reports of renal adverse events associated with COX-2 inhibitors suggest that patients with decreased effective circulating blood volume, salt depletion, and renal insufficiency have an increased likelihood of renal-related adverse events. Because many older patients have conditions that place them in one of the “at-risk” categories, this population should be monitored closely for the development of renal adverse events from any NSAIDs, including COX-2-selective agents.

Cardiovascular risk profile of antirheumatic agents in patients with osteoarthritis and rheumatoid arthritis

Several new drugs have become available for the treatment of patients with osteoarthritis and rheumatoid arthritis (RA). These agents include selective cyclooxygenase (COX)-2 inhibitors, leflunomide and anti-tumour necrosis factor (TNF)-alpha antagonists. COX-2 inhibitors have a more favourable gastrointestinal adverse effect profile than conventional non-steroidal anti-inflammatory drugs (NSAIDs). However, the COX-2 inhibitors are also associated with hypertension, oedema and congestive heart failure, the well-known adverse effects of conventional NSAIDs. Patients with treated hypertension should be monitored regularly when conventional NSAIDs or COX-2 inhibitors are administered. At present, there is a considerable debate regarding the risk of cardiovascular events with the COX-2 inhibitors. The available literature gives no unequivocal answers. This matter can only be solved by an appropriate trial assessing the cardiovascular risk of these agents. Patients with RA appear to have an enhanced cardiovascular risk which might be related to an unfavourable lipid profile. Corticosteroids induce hypercholesterolaemia in patients other than those with RA. It was recently shown that total and high-density lipoprotein (HDL) cholesterol were low in patients with RA who had a high disease activity. Contrary to the expectation, combination therapy with prednisolone rapidly improved the atherogenic index (total/HDL cholesterol). Ongoing studies investigating this topic are underway. It is not known to what extent corticosteroids induce hypertension in patients with RA. Hence, we advocate blood pressure control for these patients. A small percentage of patients with RA develop hypertension when taking leflunomide, and no other serious cardiovascular adverse effects have been reported in the literature. Blood pressure monitoring is recommended especially in the first months of treatment. TNFalpha antagonists are contraindicated in patients with RA who have congestive heart failure. No specific cardiovascular adverse effects have been reported with the use of these agents in the non-cardiovascular compromised patient. TNFalpha antagonists are the most powerful anti-inflammatory drugs presently available. As inflammation plays an important role in RA as well as in cardiovascular disease and, in view of the increased cardiovascular risk in RA, it is tempting to expect that suppression of inflammation ultimately will lower the cardiovascular morbidity and mortality in patients with RA.

Oral and intra-articular remedies: Review of papers published from March 2001 to February 2002

There have been considerable advances in the drug treatments used to treat osteoarthritis. The development of selective cyclo-oxygenase inhibitors (COX-II) and confirmation of their efficacy and gastrointestinal safety will reduce treatment morbidity in the elderly. Guidelines for safe and appropriate use of COX-II drugs are now available. The role of anti-inflammatory drugs in precipitating cardiorenal events has been highlighted but remains to be fully evaluated. Glucosamine, diacerein, and hyaluronan may all be disease-modifying drugs for osteoarthritis but confirmatory studies are still needed.

Cyclo-oxygenase-2 inhibition increases blood pressure in rats

1 It is known that nonselective cyclo-oxygenase (COX) inhibitors have small but significant effects on blood pressure (BP), most notably in hypertensive patients on antihypertensive medication. Whether selective COX-2 inhibitors also interfere with BP regulation is not well understood. Therefore, we aimed to examine the effect of chronic treatment with a selective COX-2 inhibitor (rofecoxib) on systolic blood pressure (sBP) in normotensive Wistar-Kyoto rats (WKY) and on the developmental changes of sBP in young spontaneously hypertensive rats (SHR). In addition, we investigated a possible influence of salt intake on the effects of COX-2 inhibition on BP in these two rat strains. 2 Rofecoxib dose dependently increased sBP and decreased plasma levels of 6-keto prostaglandin (PG)F(1alpha) in WKY rats fed a normal salt diet (0.6% NaCl, wt wt(-1)), without affecting serum thromboxane (TX)B(2) levels. 3 Rofecoxib significantly elevated sBP in both rat strains fed normal salt or high salt diet (8% NaCl, wt wt(-1)), but not in rats on low salt intake (0.02% NaCl, wt wt(-1)). 4 Rofecoxib significantly decreased plasma levels of 6-keto PGF(1alpha) in both rat strains fed normal or high salt diet, but not in rats during low salt intake. 5 Rofecoxib exerted no influence on the changes of body weight nor on water intake. Plasma renin activity (PRA) and renocortical renin mRNA abundance were not changed by rofecoxib, but plasma aldosterone concentration (PAC) was significantly reduced. 6 These results suggest that chronic inhibition of COX-2 causes an increase of blood pressure that depends on prostacyclin synthesis. Furthermore, this increase is independent on genetic predisposition and can be prevented by salt deprivation. Since water intake and body weight gain were not changed by rofecoxib, fluid retention appears not to be a major reason for the development of hypertension. Similarly, an activation of the renin-angiotensin-aldosterone axis appears to be an unlikely candidate mechanism.

High blood pressure in the geriatric population: treatment considerations

Increases in blood pressure (BP), particularly systolic BP, have traditionally been considered to be a normal or "physiologic" component of the aging process. However, it is now clear that elevated BP, particularly systolic BP, represents a pathophysiologic manifestation of altered cardiovascular physiology and structure, ultimately manifesting as increased cardiovascular morbidity and mortality (myocardial infarction, stroke, and total cardiovascular death rates). More than one half of the population aged 65 or older have hypertension, defined as BP > or = 140/90 mm Hg. Framingham data indicate that the risk of coronary heart disease increases with lower diastolic BP at any level of systolic BP > or = 120 mm Hg, thus further stressing the importance of pressure-induced arterial vascular compliance changes and introducing pulse pressure as an important predictor of cardiovascular risk. Geriatric hypertension is generally of a salt-sensitive nature and often associated with impaired baroreflex function. Reduction in sodium intake is important and effective in older patients, and should be initiated before or together with drug therapy. Encouraging data from clinical trials now strongly support the aggressive anti-hypertensive treatment of elderly patients. A recent meta-analysis of eight outcome trials evaluating the risks of treated and untreated isolated systolic hypertension has demonstrated a 30% reduction in combined fatal and nonfatal stroke, a 26% reduction in fatal and nonfatal cardiovascular events, and a 13% reduction in total mortality. Those drugs effective in younger patients also appear effective in the elderly; low-dose thiazides (alone or in combination with potassium sparing agents), beta blockers, long-acting dihydropyridine calcium antagonists, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers all have demonstrated efficacy. In selecting an agent, it is important to consider comorbid disease states, and to recognize the potential of all nonsteroidal anti-inflammatory drugs, whether conventional or cyclooxygenase-2 specific, to increase BP or interfere with other antihypertensive agents. In general, the elderly should be treated to target BP levels identical to those suggested for younger patients, although a more gradual reduction to target, perhaps with an intermediate BP goal of < 160 mm Hg, may be advisable.

Opposite effects of cyclooxygenase-1 and -2 activity on the pressor response to angiotensin II

Therapeutic use of cyclooxygenase-inhibiting (COX-inhibiting) nonsteroidal antiinflammatory drugs (NSAIDs) is often complicated by renal side effects including hypertension and edema. The present studies were undertaken to elucidate the roles of COX1 and COX2 in regulating blood pressure and renal function. COX2 inhibitors or gene knockout dramatically augment the pressor effect of angiotensin II (Ang II). Unexpectedly, after a brief increase, the pressor effect of Ang II was abolished by COX1 deficiency (either inhibitor or knockout). Ang II infusion also reduced medullary blood flow in COX2-deficient but not in control or COX1-deficient animals, suggesting synthesis of COX2-dependent vasodilators in the renal medulla. Consistent with this, Ang II failed to stimulate renal medullary prostaglandin E(2) and prostaglandin I(2) production in COX2-deficient animals. Ang II infusion normally promotes natriuresis and diuresis, but COX2 deficiency blocked this effect. Thus, COX1 and COX2 exert opposite effects on systemic blood pressure and renal function. COX2 inhibitors reduce renal medullary blood flow, decrease urine flow, and enhance the pressor effect of Ang II. In contrast, the pressor effect of Ang II is blunted by COX1 inhibition. These results suggest that, rather than having similar cardiovascular effects, the activities of COX1 and COX2 are functionally antagonistic.

The demographics of chronic pain management

Pain is the most common symptom for which patients seek care. The management of pain advanced considerably with the development of cyclooxygenase (COX)-2-specific inhibitors (coxibs). The clinical usefulness of nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) is often limited by the occurrence of adverse effects, such as gastric toxicity and bleeding complications, which have been attributed to the inhibition of COX-1. At the recommended dosage by targeting only COX-2, coxibs offer patients anti-inflammatory and analgesic relief with reduced gastrotoxicity compared with traditional NSAIDs. Individualization of therapy based on a careful assessment of risks versus benefits of different agents is an important consideration in pain management. This review summarizes clinical evidence of the comparable efficacy but improved tolerability of the coxibs compared with conventional NSAIDs. Important patient considerations and risk factors involved in the selection of appropriate analgesic/anti-inflammatory treatments are highlighted.

Physician-reported management of edema and destabilized blood pressure in cyclooxygenase-2-specific inhibitor users with osteoarthritis and treated hypertension

BACKGROUND

The addition of a nonsteroidal anti-inflammatory drug to the regimen of a patient with treated hypertension can cause a destabilization of blood pressure.

OBJECTIVE

The aim of this study was to describe physician-reported management of clinically significant edema and/or destabilized blood pressure in patients with osteoarthritis (OA) and hypertension when initiating therapy with rofecoxib or celecoxib.

METHODS

A cross-sectional survey was administered to physicians who attended one of several arthritis consultant programs sponsored by Pharmacia Corporation, with attendees selected by local sales representatives. Each program included a clinical presentation by a physician concerning the cardiorenal safety of celecoxib, followed by a consultative presentation and session led by a Pharmacia Clinical Education Manager.

RESULTS

A total of 828 physicians in the following specialties completed the survey: family practice (33.0%), internal medicine (25.0%), orthopedics (15.2%), and rheumatology (11.4%). Responding physicians expected that the majority of patients who experienced edema would contact them (68.4%). They reported that they schedule follow-up visits for blood pressure monitoring 65.6% of the time after initiating a cyclooxygenase-2 (COX-2)-specific inhibitor, with family practitioners and internists most likely to indicate that they would do so and orthopedists least likely. Responding physicians indicated that the presence of edema and destabilized blood pressure generally led to discontinuation of the COX-2-specific inhibitor (58%-82% of the time). Internists and family practitioners were most likely to report that they treat edema by initiating or modifying diuretic therapy (33%-51% of the time). For destabilized blood pressure, an antihypertensive drug was reported to be initiated or modified 40% to 55% of the time by family practitioners and internists, whereas orthopedists indicated that they referred patients to the primary care provider. The COX-2-specific inhibitor prescribed resulted in management differences: physicians indicated that they were more likely to switch from rofecoxib to celecoxib in the event of edema or destabilized blood pressure, whereas they were more likely to adjust the celecoxib dose than the rofecoxib dose. Because the data were captured from convenience samples of physicians attending sponsored meetings, it is possible that respondents provided the answers they thought the sponsor would want. Because this was a cross-sectional survey, reported behavior was not compared with actual behavior.

CONCLUSIONS

A significant percentage of physicians reported that they monitor patients with OA and hypertension for the occurrence of destabilized blood pressure and edema after initiation of a COX-2-specific inhibitor. Physicians indicated that they would nearly always intervene when either event is identified.

Specific cyclooxygenase-2 inhibitors: what have we learned since they came into widespread clinical use?

Specific inhibitors of cyclooxygenase-2 were introduced into widespread clinical use in 1999. Since that time, celecoxib and rofecoxib have become two of the most commonly prescribed medications in the United States. Clinical trials using these medications for arthritis and pain have uniformly demonstrated efficacy superior to that of placebo and similar to that of nonsteroidal anti-inflammatory drugs. However, controversy surrounding the proper place of cyclooxygenase-2 inhibitors in the hierarchy of treatment for arthritis continues, based primarily on their higher cost compared with that of acetaminophen and nonsteroidal anti-inflammatory drugs. A decreased risk of gastrointestinal toxicity remains the primary justification for using the more expensive cyclooxygenase-2 inhibitors in preference to nonsteroidal anti-inflammatory drugs. The renal and cardiovascular effects of rofecoxib and celecoxib have been investigated in relation to nonsteroidal anti-inflammatory drugs and to one another. The data with respect to alteration in renal function, lower extremity edema, and hypertension indicates that cyclooxygenase-2 inhibitors affect the kidney in a manner similar to that of nonsteroidal anti-inflammatory drugs. The data comparing the cyclooxygenase-2 inhibitors is difficult to interpret because it is not clear that comparable doses have been used in clinical trials. The potential thrombogenic risk of cyclooxygenase-2 inhibitors remains controversial, and conflicting data exist. It remains important to increase our understanding of the place of these agents in clinical practice from the perspective of efficacy, toxicity, and cost.

Areas of emerging interest in analgesia: cardiovascular complications

Many people obtain symptomatic relief from acute, chronic, or recurring pain conditions by using an over-the-counter analgesic. As with the use of any drug, this involves achieving the appropriate balance between potential benefit and risk of harm. The adverse effects of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) in the gastrointestinal (GI) tract are widely appreciated. On the basis of their pharmacology, however, these drugs also have the potential for causing adverse effects in the cardiovascular system. This is particularly the case in certain overlapping populations (eg, the elderly or those with cardiac failure, hypertension, or renal impairment). And the size of the exposed populations and the fact they comprise people likely to require pain management because of concomitant illnesses make the cardiovascular implications of analgesic use potentially a more serious issue for public health than the more widely recognized GI complications of aspirin and NSAID use. This article discusses the impact on the cardiovascular system of different classes of analgesics (NSAIDs, the new cyclooxygenase-2-selective inhibitors [CSIs], and paracetamol) in terms of cardiac function, thrombotic and cardioprotective potential, and hypertension. It identifies patients at risk for analgesic-related cardiovascular adverse events, and considers their options for managing mild-to-moderate pain. Unlike that of the NSAIDs and CSIs, the pharmacology of paracetamol provides no signal for risk of cardiovascular adverse events, and paracetamol should, therefore, be considered as first-line therapy in patients with cardiovascular disease.

Cardiovascular hazard of selective COX-2 inhibitors: myth or reality?

Since 1998, two selective inhibitors of COX-2 have been approved in many countries for the treatment of rheumatoid arthritis, osteoarthritis and acute pain. These new drugs have a significantly reduced gastrointestinal toxicity when compared with non-selective COX inhibitors. However, the results of two large clinical trials conducted in patients with osteoarthritis and rheumatoid arthritis have recently raised some concerns regarding the cardiovascular safety of these new drugs. The purpose of this paper is to review the potential mechanisms whereby selective COX-2 inhibitors could increase the cardiovascular risk of patients and to analyse the data indicating that this clinical risk indeed exists. The authors' analysis shows that even though there are pathophysiological mechanisms which could explain why selective COX-2 inhibition might increase the cardiovascular risk in patients, the actual level of evidence demonstrating that the risk is indeed increased is weak. Because of the importance of the issue, additional studies must be conducted with this class of agents. Meanwhile, it is crucial to emphasise that neither selective COX-2 inhibitors nor conventional NSAIDs replace aspirin in patients with a high cardiovascular risk.

Effects of celecoxib on ambulatory blood pressure in hypertensive patients on ACE inhibitors

Nonselective nonsteroidal anti-inflammatory agents have been shown to attenuate the antihypertensive efficacy of ACE inhibitors with average increases in systolic blood pressure (BP) of 5 to 10 mm Hg. Less is known about the specific cyclooxygenase-2 (COX-2) inhibitors now widely used for the treatment of arthritis. The objective of this study was to determine the effects of celecoxib compared with placebo on 24-hour BP levels in ACE inhibitor-treated patients with hypertension. This was a randomized, double-blind, placebo-controlled, parallel-group clinical trial involving 178 men and women (mean age, 53 years) with essential hypertension who were treated and controlled with lisinopril monotherapy (10 to 40 mg daily). Baseline BP values were obtained using 24-hour ambulatory recordings. Patients received either celecoxib, 200 mg twice daily (twice the recommended dose for osteoarthritis) (n=91), or placebo (n=87) for 4 weeks, and changes in the 24-hour BP, body weight, and clinical laboratory parameters were assessed. Mean changes from baseline in the 24-hour systolic and diastolic BP were 2.6/1.5+/-0.9/0.6 mm Hg on celecoxib versus 1.0/0.3+/-1/0.6 mm Hg on placebo (P=0.34 for systolic BP; P=0.45 for diastolic BP). The proportion of patients whose 24-hour BP increased by at least 5, 10, 15, or 20 mm Hg were also similar on celecoxib and placebo. No changes in body weight, serum creatinine, or potassium occurred in either group. Thus, these data demonstrate that high doses of celecoxib have no significant effect on the antihypertensive effect of the ACE inhibitor lisinopril. The placebo-subtracted changes observed in 24-hour BP (1.6/1.2 mm Hg) are less than what has been reported for nonselective nonsteroidal anti-inflammatory agents in ACE inhibitor-treated patients.

Cox-2 inhibitors: today and tomorrow

The elucidation of inducible cyclooxygenase (Cox-2) dependent inflammatory pathways led to the development of specific Cox-2 inhibitors, the coxibs. These agents include the currently available celecoxib and rofecoxib and such second-generation agents as parecoxib, valdecoxib, and etoricoxib. The therapeutic advantage of coxibs is founded primarily in their lack of significant gastrointestinal (GI) side effects. Clinical trials have demonstrated the efficacy of coxibs to be completely comparable with traditional nonsteroidal anti-inflammatory drugs (NSAIDs), and pharmacoeconomics suggest favorable cost/benefit ratios with these agents compared with traditional NSAIDs, related to their reduced GI complication profiles and lower indirect costs associated with disability. Although several clinical questions remain (eg, use with low-dose aspirin, risk of thrombosis, myocardial infarction, edema, and hypertension), the emergence and clinical utility of coxibs is likely to continue on the basis of their efficacy and relative GI safety advantage. Although newer, more specific Cox-2 inhibitors may alter the choice, it is likely that this class of anti-inflammatories will become (if they have not already) the drugs of first choice in the treatment of acute pain, chronic pain, and most rheumatic conditions in the 21st century. In addition to the treatment of rheumatic conditions, it is possible that coxibs will also be of clinical utility in protection against malignant transformation and Alzheimer disease.

Considerations for the safe prescribing and use of COX-2-specific inhibitors

The majority of the "Australian COX-2-Specific Inhibitor (CSI) Prescribing Group" endorse the following points: CSIs are equivalent to non-steroidal anti-inflammatory drugs (NSAIDs) as anti-inflammatory agents. CSIs and NSAIDs modify symptoms but do not alter the course of musculoskeletal disease. CSIs do not eliminate the occurrence of ulcers or their serious complications, but are associated with considerably fewer peptic ulcers, slightly fewer upper GI symptoms and, according to published reports, fewer serious upper GI complications, notably bleeding, than CSIs and NSAIDs have similar effects on renal function and blood pressure. Whether any CSI poses a risk to cardiovascular safety remains subject to debate. Comorbidities and coprescribed drugs must be considered before initiating CSI (or NSAID) therapy. Patients prescribed CSIs (or NSAIDs) should be reviewed within the first few weeks of therapy to assess effectiveness, identify adverse effects and determine the need for ongoing therapy.

A new role for opioids in the treatment of arthritis

Arthritis, rheumatic diseases, spinal and peripheral joint disorders share in common a legacy of chronic pain. At the turn of the millennium, nonsteroidal anti-inflammatories (NSAIDs) had replaced aspirin as the agents most commonly used to deal with rheumatic symptoms, including pain. Paracetamol (acetaminophen) was the most common alternative analgesic for minor pain. Opioids were most commonly used on an ad-lib basis, usually for 'breakthrough' pain. However, neurobiological research has confirmed the basis for 24-hour around-the-clock complete suppression of chronic nonmalignant pain. This avoids the 'wind up' that leads to intractable pain progression. Proper monitoring, in the absence of the end organ toxicity seen with NSAIDs, allows a change in direction to opioids for arthritis for more severe pain. This requires understanding the responsibilities of maintaining opioids, in properly selected patients, based upon host response and informed consent. Under such circumstances, evidence-based trials support the use of stronger opioids in recalcitrant chronic pain of arthritis. Thus, we endeavour to better fulfill our Oath of Hippocrates: 'to relieve pain and suffering'.

Simple and sensitive method for the determination of celecoxib in human serum by high-performance liquid chromatography with fluorescence detection

A simple method is described for the determination of the cyclooxygenase-2 specific inhibitor celecoxib in human serum by HPLC using the demethylated analogue as internal standard. After protein precipitation with acetonitrile, samples were extracted with chloroform. Separation was achieved on a Prontosil C18 AQ column (150x3 mm I.D., 3-microm particle size) at a flow-rate of 0.35 ml/min using water-acetonitrile (40:60, v/v) as the mobile phase. Using fluorescence detection with excitation at 240 nm and emission at 380 nm, the limit of quantification was 12.5 ng/ml for a sample size of 0.5 ml of serum. The assay was linear in the concentration range of 12.5-1500 ng/ml and showed good accuracy and reproducibility. At all concentrations intra- and inter-assay variabilities were below 11% with less than 9% error. The method was applied to the determination of celecoxib for pharmacokinetic studies in man.

Selective cyclooxygenase-2 (COX-2) inhibitors and potential risk of cardiovascular events

Selective cyclooxygenase-2 (COX-2) inhibitors were developed as a response to the gastrointestinal toxicity of conventional nonsteroidal anti-inflammatory agents (NSAIDs). However, COX-2 inhibitors decrease vascular prostacyclin (PGI(2)) production and may disrupt the homeostatic mechanisms that limit the effects of platelet activation. Basic and clinical data raise concerns about a potential prothrombotic effect of this class of drugs. The widespread popularity of these agents mandates their prospective evaluation in patients with cardiovascular diseases or who are at risk for cardiovascular events.

Recent developments in toxic nephropathy

Toxic nephropathy is an important cause of reversible renal injury if detected early. Renal damage can be due to several different mechanisms affecting different segments of the nephron, renal microvasculature or interstitium. Clinical signs may not be apparent in the early stages and assessment of renal function should include thorough evaluation of glomerular filtration rate, proximal and distal tubular function. A kidney biopsy may be indicated to establish the cause and effect relationship. The presence of comorbid conditions such as older age, diabetes mellitus, hypertension and congestive heart failure have a significant influence on the patient's ability to recover from the toxic effects. A significant degree of drug-induced renal toxicity is only acceptable if the causative agent is used for the curative treatment of an underlying disease but not if the aim is the palliative or supportive therapy. The decision to reduce the dose or to stop the toxic agent must be based on the ultimate goal of therapy and the patient's baseline health status.

Comparison of thromboembolic events in patients treated with celecoxib, a cyclooxygenase-2 specific inhibitor, versus ibuprofen or diclofenac

It has been hypothesized that cyclooxygenase 2 specific inhibitors may increase the risk of cardiovascular (CV) thromboembolic events because of their inhibition of vascular prostacyclin synthesis and lack of an effect on platelet thromboxane A(2) production and aggregation. Thus, we analyzed the data for celecoxib and nonsteroidal anti-inflammatory drugs (NSAIDs) from the Celecoxib Long-term Arthritis Safety Study to determine the incidences of serious CV thromboembolic events. This trial included 3,987 persons randomized to celecoxib 400 mg twice daily (2,320 person-years of exposure) and 3,981 persons randomized to either ibuprofen 800 mg 3 times daily or diclofenac 75 mg twice daily (2,203 person-years). Because acetylsalicylic acid (ASA) use for CV risk prophylaxis (< or =325 mg/day) was permitted, separate analyses were performed for all patients and those not taking ASA. The incidences of serious CV thromboembolic events (myocardial infarction, stroke, CV deaths, and peripheral events) were similar, and not significantly different, between celecoxib and NSAID comparators (combined or individually) for all patients as well as the subgroup of patients not taking ASA. This observation was true both for all serious CV thromboembolic events, as well as for individual events. No increase in myocardial infarction was apparent, even in patients not taking ASA who were candidates for secondary prophylaxis for myocardial infarction. The relative risks for celecoxib versus NSAIDs for serious CV thromboembolic events were 1.1 for all patients and 1.1 for the subgroup of patients not taking ASA (95% confidence interval 0.7 to 1.6 and 0.6 to 1.9, respectively). In addition, the incidences of adverse CV events such as hypertension, edema, and congestive heart failure were similar to, or significantly lower than, NSAID comparators regardless of the use of ASA. Thus, these analyses demonstrate no increased risk of serious CV thromboembolic events associated with celecoxib compared with conventional NSAIDs and therefore do not support the hypothesis of a class adverse effect of cyclooxygenase 2 specific inhibitors on the CV system.

Use of nonopioid analgesics and adjunctive agents in the management of pain in rheumatic diseases

Antirheumatic analgesic medications generally fall into one of the following categories: acetaminophen, corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol, traditional opioids, or adjunctive analgesics. This article does not discuss corticosteroids, opioids, or topical analgesics. Acetaminophen, usually indicated early for mild pain, is often used in combination with other drugs. It has established safety. Traditional NSAIDs are effective in relieving moderate pain in certain inflammatory and noninflammatory conditions. There are many effective choices, but as a class it is fraught with the risk of serious peptic ulcer disease and its complications. Cyclooxygenase-2 specific inhibitors are NSAIDS that reduce the gastrointestinal risk and platelet-mediated bleeding. All NSAIDs may produce peripheral edema, hypertension, and potentiate warfarin. The evidence that coxibs cause thrombotic heart disease is weak. Tramadol is an alternative to musculoskeletal pain management, particularly in patients with moderate to moderately severe pain who do not respond to or who cannot tolerate acetaminophen, NSAIDs, or opioids. The role of analgesic adjuvants is discussed.

Selective Cyclo-Oxygenase-2 Inhibitors and Myocardial Infarction

There are concerns that selective cyclo-oxygenase (COX)-2 inhibitors may be prothrombotic and increase the risk of myocardial infarction. This has largely arisen because of an unexpected finding of a higher rate of myocardial infarction in patients receiving rofecoxib compared with patients receiving naproxen in a study of gastrointestinal toxicity. The results of this study, a similar study of celecoxib versus ibuprofen or diclofenac, and data obtained from a meta-analysis of aspirin (acetylsalicylic acid) primary prevention trials suggest that differences in the rates of myocardial infarction between rofecoxib and naproxen may have been due to an unexpectedly low rate of myocardial infarction in patients receiving naproxen. However, population surveillance data also suggest that rofecoxib may be associated with a greater risk of myocardial infarction than celecoxib and certain nonselective nonsteroidal anti-inflammatory drugs. The magnitude of this increase in risk, if real, is uncertain but it is likely to be relatively small in patients for whom cardiovascular prophylaxis with aspirin is not indicated. Patients who require nonsteroidal anti-inflammatory therapy for arthritis and who are at high risk of cardiovascular disease should receive aspirin, probably in conjunction with selective COX-2 inhibitor therapy, as the risk of gastrointestinal ulceration may be lower than for aspirin plus a nonselective nonsteroidal anti-inflammatory drug. In patients who do not require aspirin for the prevention of cardiovascular events, the lower risk of gastrointestinal ulceration associated with COX-2 inhibitor compared with non-selective nonsteroidal anti-inflammatory drugs would be expected to outweigh any increase in the risk of myocardial infarction, if one exists.

COX-2 inhibitors. Are they nonsteroidal anti-inflammatory drugs with a better safety profile?

In the treatment of arthritis, NSAIDs are some of the most commonly used drugs, although the prescription of such drugs has been questioned due to their inherent risks for gastrointestinal compromise, platelet effects, and the potential for renal toxicity with long-term use. With the availability of celecoxib and rofecoxib, 2 cyclooxygenase (COX-2) inhibitors (or COX-1 sparing agents) as new forms of NSAIDs, these issues have become magnified not only in the context of risk-to-benefit ratios but also interms of pharmacoeconomics because they have been proven to be equally efficacious as the nonselective NSAIDs, with an improved safety profile particularly within the gastrointestinal tract, but at a significantly increased cost.

Renal and cardiovascular effects of selective cyclooxygenase-2 inhibitors

Selective inhibition of cyclooxygenase-2 (COX-2) was proposed as a novel anti-inflammatory and analgesic treatment with a reduced profile of gastrointestinal side effects compared with conventional nonsteroidal anti-inflammatory drugs (NSAIDs). Although perceived as an inducible enzyme by inflammatory and other stimuli, COX-2 is constitutively expressed in the kidney. In this review, we focus on renal and cardiovascular (CV) physiological and pathophysiological characteristics of COX-2 and renal and CV aspects of treatment with selective COX-2 inhibitors. Both clinical and experimental studies have shown that renal and CV effects of COX-2 inhibitors are similar to those of NSAIDs. These effects include sodium, potassium, and water retention and decreases in renal function, as well as mild to modest increases in blood pressure (BP) and edema. These deleterious effects are amplified in patients with volume and/or sodium depletion. The concomitant administration of COX-2 inhibitors may destabilize BP control in hypertensive patients treated with antihypertensive agents. In contrast to the normal kidney, which could constitute a target for adverse actions of COX-2 inhibitors, recent experimental studies showed increased renal COX-2 expression in several models of renal injury, such as the remnant kidney, renovascular hypertension, and diabetes, and implicated COX-2 in the progression of renal failure. This suggests that COX-2 inhibitors may confer a renoprotective effect in diverse renal disorders. These intriguing formulations must be delineated further in appropriately designed prospective clinical trials.

Pharmacological therapies for the treatment of osteoarthritis

Non-pharmacological interventions are the first-line therapy for osteoarthritis. If non-pharmacological therapy fails, paracetamol (up to 4 g daily) should be added. If paracetamol fails, the patient's risk factors for gastrointestinal and renal disease should be assessed. In patients with gastrointestinal risk factors, a COX-2-specific inhibitor (CSI) would be used in preference to a conventional non-steroidal anti-inflammatory drug (NSAID). In patients with renal risk factors, NSAIDs and CSIs should be used with care. In patients who continue to have problems, other treatments should be considered; these might include intra-articular hyaluronan or depot corticosteroid, analgesia or glucosamine.