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

Rheumatic disease in the elderly: rheumatoid arthritis

This review summarizes the different aspects of rheumatoid arthritis and the spectrum of diseases that can present as rheumatoid arthritis-like arthritis in the elderly population. With the aging of Western population, different forms of inflammatory arthritis' prevalence and incidence are increasing in the elderly persons. Difficulties in establishing the diagnosis and introducing new treatment modalities in this patient group poses a great challenge for the clinicians. The management of inflammatory arthritis in the elderly requires special consideration in regard to the comorbidities and increased frequency of adverse events. There is definitely a substantial need for improving different aspects of diagnostic and therapeutic interventions that will reduce the impact of inflammatory arthritis in the growing elderly population.

Resistant hypertension

Hypertension that remains above 140/90 mmHg despite the use of three antihypertensive drugs in a rational combination at full doses and including a diuretic is known as 'resistant'. The percentage of hypertensives whose condition is resistant varies in large part upon the setting: those seen in general practice show a prevalence of perhaps 5%; those seen by nephrologists, probably 50%. This paper reviews the major causes of resistant hypertension and provides specific recommendations for the evaluation and management of patients with this threatening condition.

Cyclo-oxygenase-2 inhibitors: when should they be used in the elderly?

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.

Anti-inflammatory strategies in hypertension: focus on COX-1 and COX-2

An increasing body of evidence suggests that elevated levels of blood pressure may induce a proinflammatory response. Indeed, both C-reactive protein and blood pressure are independent determinants of cardiovascular risk, and, in combination, each parameter has additional predictive value. Hence, strategies targeted to lower blood pressure and reduce vascular inflammation may potentially provide clinical benefit. In this review, we discuss the role of chronic low-grade inflammation in the context of cardiovascular disease with a focus on roles of cyclooxygenase-1 and -2 in potential anti-inflammatory treatment strategies.

Differences in outcomes of patients with congestive heart failure prescribed celecoxib, rofecoxib, or non-steroidal anti-inflammatory drugs: population based study

OBJECTIVES

To compare the risk of death and recurrent congestive heart failure in elderly patients prescribed celecoxib, rofecoxib, or non-steroidal anti-inflammatory drugs (NSAIDs) and to determine whether there are class differences between celecoxib and rofecoxib.

DESIGN

Population based retrospective cohort study.

SETTING

Databases of hospital discharge summaries and prescription drug claims in Quebec.

PARTICIPANTS

2256 patients aged 66 or more prescribed celecoxib, rofecoxib, or an NSAID after an index admission for congestive heart failure between April 2000 and March 2002.

MAIN OUTCOME MEASURES

Time to all cause death and recurrent congestive heart failure, combined and separately.

RESULTS

The risk of death and recurrent congestive heart failure combined was higher in patients prescribed NSAIDs or rofexocib than in those prescribed celecoxib (hazard ratio 1.26, 95% confidence interval 1.00 to 1.57 and 1.27, 1.09 to 1.49, respectively). The findings were similar when the outcomes were assessed separately. In pairwise analysis, the risks of death and recurrent congestive heart failure, combined and separate, were similar between patients prescribed NSAIDs and rofecoxib.

CONCLUSIONS

Celecoxib seems safer than rofecoxib and NSAIDs in elderly patients with congestive heart failure. Differences were found among cyclo-oxygenase-2 inhibitors.

Role of cyclooxygenase-2 inhibitors in postoperative pain management

Cyclooxygenase (COX)-2 inhibitors are as efficacious as nonselective nonsteroidal anti-inflammatory drugs for the treatment of postoperative pain but have the advantages of a better gastrointestinal side-effect profile as well as a lack of antiplatelet effects. There have been recent concerns regarding the cardiovascular side effects of COX-2 inhibitors. Nonetheless, they remain a valuable option for postoperative pain management. The pharmacology of these agents and available studies are reviewed.

Effects of Indomethacin and Celecoxib on Renal Function in Athletes

INTRODUCTION

Strenuous exercise induces a marked reduction in renal hemodynamics. Prostaglandins (PG) play an important role in maintaining renal integrity in the face of hemodynamic changes. Inhibition of cyclooxygenase (COX) and thus PG formation can further compromise renal perfusion. The role of selective COX-2 inhibition on renal hemodynamics during exercise has not been investigated.

METHODS

Twelve healthy males (22-47 yr) took part in a randomized placebo controlled study investigating the effects of nonselective COX inhibition (indomethacin) and COX-2 selective inhibition (celecoxib) on renal hemodynamics during exercise. Renal blood flow (RBF), glomerular filtration rate (GFR), and free water clearance were measured using standard clearance techniques. Each experimental session was performed at least a week apart. The medications were taken for 36 h before study with the last dose at 0700 h on the day of study. Following baseline studies, each participant exercised for 30 min at 80% of their maximal aerobic power. Renal function was monitored for 2 h post-recovery.

RESULTS

RBF and GFR fell by 40% after exercise with no significant difference between placebo, indomethacin, or celecoxib. Indomethacin (-2.43 +/- 0.95 mL x min(-1), P < 0.007) and celecoxib (-3.88 +/- 0.94 mL x min(-1), P < 0.0001) significantly reduced free water clearance compared with placebo during recovery.

CONCLUSION

This study has confirmed that selective and nonselective COX inhibition can induce significant inhibition of free water clearance, indicating that these acute changes are regulated predominantly via COX-2. Acute cerebral edema with hyponatremia has been reported after major endurance sporting events. Identifiable risk factors include excessive hydration and use of NSAID. Impaired free water clearance during exercise potentiated by COX inhibition provides a pathophysiological explanation for these observations.

Blood Pressure in Native Americans Switched from Celecoxib to Rofecoxib

BACKGROUND:

Nonsteroidal antiinflammatory drugs have been associated with exacerbation of hypertension. Differing effects on blood pressure (BP) have been reported in studies comparing celecoxib and rofecoxib. Concern regarding the cardiovascular safety of the cyclooxygenase-2 (COX-2) inhibitor class has intensified since the removal of rofecoxib from the market.

OBJECTIVE:

To evaluate the effect of a formulary change from celecoxib to rofecoxib on the BP of Native American patients at an Indian Health Service medical center.

METHODS:

Medical records of patients switched from celecoxib to rofecoxib were retrospectively reviewed. BP during the respective treatments was compared as follows: measurements recorded while taking celecoxib within 6 months before the index date and while taking rofecoxib from 1 week after the index date through 6 months of treatment were averaged. Differences in systolic and diastolic BP before and after the therapy change were evaluated using a paired Student's t-test. Subgroup analysis was performed for patients with preexisting hypertension.

RESULTS:

During rofecoxib therapy, the mean systolic BP was 2.9 mm Hg higher (p = 0.015) and the mean diastolic BP was 1.5 mm Hg higher (p = 0.042) than during celecoxib therapy. Among hypertensive patients, the respective mean systolic and diastolic BPs were 4.8 mm Hg (p = 0.009) and 2.0 mm Hg (p = 0.063) higher while taking rofecoxib.

CONCLUSIONS:

Switching patients from celecoxib to rofecoxib resulted in an increase in BP, with a larger difference observed in patients with hypertension. Future studies assessing the cardiovascular safety of currently marketed and investigational COX-2 inhibitors should evaluate the possible contribution of BP effects of these agents to overall risk.

Cyclooxygenase-2 inhibitors attenuate angiotensin II-induced oxidative stress, hypertension, and cardiac hypertrophy in rats

Angiotensin II is an important oxidative stress mediator. Our previous studies have indicated that the potent antioxidative properties of acetylsalicylic acid play an important role in its cardiovascular protective effects. There are some ongoing controversies concerning the use of selective cyclooxygenase-2 inhibitors in cardiovascular disease. The aim of this study was to determine whether the cyclooxygenase-2 selective inhibitors rofecoxib and nimesulide possess antioxidative and cardiovascular protective effects against angiotensin II. Chronic subcutaneous angiotensin II infusion increased cardiovascular but not colonic tissue superoxide production, heart/body weight ratio, and blood pressure. Moreover, angiotensin II selectively increased cardiac cyclooxygenase-2 but not cyclooxygenase-1 expression, which was totally prevented by acetylsalicylic acid treatment. Similar to acetylsalicylic acid, rofecoxib or nimesulide treatments significantly attenuated angiotensin II-induced oxidative stress, hypertension, and cardiac NAD(P)H oxidase subunit p47(phox) expression. Rofecoxib also reduced cardiac hypertrophy. Treatment with nonselective anti-inflammatory drugs ibuprofen, indomethacin, or salicylic acid did not show any effect on angiotensin II-induced superoxide production, hypertension, or cardiac hypertrophy. Although acetylsalicylic acid and salicylic acid inhibited angiotensin II-induced nuclear factor kappaB (NF-kappaB) activation, nimesulide did not modify NF-kappaB activation. In conclusion, cyclooxygenase-2 pathway is implicated in angiotensin II-induced oxidative stress and deleterious cardiovascular changes. Rofecoxib and nimesulide produced significant antioxidative effect by reducing NAD(P)H oxidase-dependent superoxide generation. These effects seem to be independent of NF-kappaB inhibition.

Emerging analgesics in cancer pain management

Cancer pain is one of the most frequent symptoms in malignant disease, severely impairing the patients' quality of life. The recommendations of the World Health Organization will provide adequate pain relief for the vast majority of cancer patients. However, some patients will suffer from inadequate analgesia or intolerable side effects. Cyclooxygenase-2 (COX-2)-selective non-steroidal anti-inflammatory drugs (NSAIDs), new anticonvulsants, cannabinoids and NMDA receptor antagonists are being developed for these patients. NSAIDs with nitric oxide-releasing moieties are an interesting addition, as this new class of analgesics combines improved analgesic efficacy with higher tolerability. Conotoxins and other drugs such as nicotinic acetylcholinergic receptor agonists will be advantageous only for a few patients in the near future, as side-effect profile and risk of complications, as well as the burden on the patient, often are not worth the additional analgesic benefit.

Effect of cardiovascular comorbidities and concomitant aspirin use on selection of cyclooxygenase inhibitor among rheumatologists

OBJECTIVE

To evaluate the effects of cardiovascular comorbidities and aspirin coprescription on cyclooxygenase (COX)-2 inhibitor (coxib) prescribing patterns among rheumatologists.

METHODS

A prospective cohort study was carried out with rheumatoid arthritis and osteoarthritis patients in the Consortium of Rheumatology Researchers of North America registry. Medication and comorbidity data were obtained prospectively from physician and patient questionnaires between March 2002 and September 2003. Multivariate adjusted associations between coxib use and specific cardiovascular variables, including aspirin use, were examined.

RESULTS

A total of 3,522 arthritis patients were included. COX inhibitors, including coxibs, nonselective nonsteroidal antiinflammatory drugs (NSAIDs), and meloxicam, were prescribed to a larger proportion of osteoarthritis patients (68.4%) than rheumatoid arthritis patients (47.1%) in our study (P < 0.001). COX inhibitors were prescribed to the majority of aspirin users (51.5%) and a similar proportion of nonusers (49.8%). In multivariate analyses, independent predictors of coxib use versus nonselective NSAID use included diagnoses of osteoarthritis (odds ratio [OR] 2.52, 95% confidence interval [95% CI] 1.81-3.52) and diabetes (OR 1.63, 95% CI 1.06-2.51). Conversely, aspirin use independently predicted selection of a nonselective NSAID rather than a coxib (OR 0.73, 95% CI 0.55-0.98). Neither a history of myocardial infarction nor stroke predicted utilization of a coxib. Similarly, cardiovascular variables did not predict the use of rofecoxib versus celecoxib.

CONCLUSION

Our data indicate that COX inhibitor coprescription among aspirin users is frequent. Despite cardiovascular concerns regarding the coxibs, our data suggest that aspirin use, but not cardiovascular comorbidities, predicted the selection of nonselective NSAIDs over coxibs.

Cardiovascular events associated with rofecoxib in a colorectal adenoma chemoprevention trial

BACKGROUND

Selective inhibition of cyclooxygenase-2 (COX-2) may be associated with an increased risk of thrombotic events, but only limited long-term data have been available for analysis. We report on the cardiovascular outcomes associated with the use of the selective COX-2 inhibitor rofecoxib in a long-term, multicenter, randomized, placebo-controlled, double-blind trial designed to determine the effect of three years of treatment with rofecoxib on the risk of recurrent neoplastic polyps of the large bowel in patients with a history of colorectal adenomas.

METHODS

A total of 2586 patients with a history of colorectal adenomas underwent randomization: 1287 were assigned to receive 25 mg of rofecoxib daily, and 1299 to receive placebo. All investigator-reported serious adverse events that represented potential thrombotic cardiovascular events were adjudicated in a blinded fashion by an external committee.

RESULTS

A total of 46 patients in the rofecoxib group had a confirmed thrombotic event during 3059 patient-years of follow-up (1.50 events per 100 patient-years), as compared with 26 patients in the placebo group during 3327 patient-years of follow-up (0.78 event per 100 patient-years); the corresponding relative risk was 1.92 (95 percent confidence interval, 1.19 to 3.11; P=0.008). The increased relative risk became apparent after 18 months of treatment; during the first 18 months, the event rates were similar in the two groups. The results primarily reflect a greater number of myocardial infarctions and ischemic cerebrovascular events in the rofecoxib group. There was earlier separation (at approximately five months) between groups in the incidence of nonadjudicated investigator-reported congestive heart failure, pulmonary edema, or cardiac failure (hazard ratio for the comparison of the rofecoxib group with the placebo group, 4.61; 95 percent confidence interval, 1.50 to 18.83). Overall and cardiovascular mortality was similar in the two groups.

CONCLUSIONS

Among patients with a history of colorectal adenomas, the use of rofecoxib was associated with an increased cardiovascular risk.

The cyclooxygenase-2 pathway as a target for treatment or prevention of cancer

Cyclooxygenase (COX)-2, an inducible enzyme involved in prostaglandin biosynthesis, has attracted considerable attention recently, due to its role in human cancer biology. Several studies have correlated an increase in the expression of COX-2 with a poor clinical outcome, while epidemiological studies demonstrate a reduced risk of cancer mortality in persons with longterm, chronic ingestion of non-steroidal anti-inflammatory drugs (NSAIDs). Originally, these observations were made in patients with colorectal cancer, and subsequent studies suggest a protective role of NSAIDs in other human cancers as well. With the development of COX-2 specific inhibitors, numerous laboratory and clinical studies are underway to help understand the role of COX-2 in cancer and the potential use of COX-2 selective inhibitors for cancer treatment or prevention. This review focuses on the physiological function of COX, and the clinical rationale for evaluating COX-2 selective inhibitors for use in oncology.

Selective COX-2 Inhibitors and Renal Injury in Salt-Sensitive Hypertension

In view of the ongoing controversy of cardiorenal safety of selective COX-2 inhibitors (coxibs), the present study was designed to examine the effects of 2 different coxibs, celecoxib and rofecoxib, compared with a traditional NSAID, diclofenac, and placebo on renal morphology and function in salt-sensitive hypertension. Salt-sensitive (DS) and salt-resistant (DR) Dahl rats were fed with NaCl-enriched diet (4% NaCl) for 8 weeks. Diclofenac (DS-diclofenac), rofecoxib (DS-rofecoxib), celecoxib (DS-celecoxib), or placebo was added to chow from weeks 6 to 8. Immunostaining for monocytes/macrophages (ED1) and cytotoxic T lymphocytes (CD8) was performed. In addition, renal morphology and proteinuria were assessed. Renal cortex mRNA was isolated for determination of COX-2, eNOS, and CRP mRNA by real-time reverse-transcriptase polymerase chain reaction. Untreated hypertensive animals showed glomerular injury including collapsing glomerulopathy, mesangial sclerosis, mesangiolysis, extracapillary proliferation, protein drops, and an especially high grade of glomerulosclerosis ( P <0.05 versus DR-placebo) and CD8-positive and ED1-positive cells ( P <0.01 versus DR-placebo), which was improved by celecoxib but not by diclofenac and rofecoxib. C-reactive protein mRNA in renal cortex was increased in DS-placebo animals ( P <0.05 versus DR-placebo) and normalized by celecoxib ( P <0.05 versus DS-placebo), whereas eNOS mRNA was decreased in the DS-rofecoxib group ( P <0.05 versus DR-placebo, DS-celecoxib, and DS-diclofenac). Proteinuria was observed in hypertensive animals ( P <0.0001 versus DR-placebo), increased by rofecoxib ( P <0.05 versus DS-placebo), and normalized by celecoxib ( P =0.0015 versus DS-placebo). This head-to-head comparison of selective and nonselective COX inhibitors demonstrates differential effects of coxibs on renal morphology and function in salt-dependent hypertension.

Rofecoxib for osteoarthritis

BACKGROUND

Editor's note: The anti-inflammatory drug rofecoxib (Vioxx) was withdrawn from the market at the end of September 2004 after it was shown that long-term use (greater than 18 months) could increase the risk of heart attack and stroke. Further information is available at www.vioxx.com. Osteoarthritis is a chronic disease of the joints, characterised by joint pain, stiffness and loss of physical function. Its onset is age-related and occurs usually between the ages of 50 and 60. It is the commonest cause of disability in those aged over 65, with OA of the knee and/or hip affecting over 20 per cent of the elderly population.

OBJECTIVES

To establish the efficacy and safety of rofecoxib in the management of OA by systematic review of available evidence.

SEARCH STRATEGY

We searched the following databases up to August 2004: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, National Research Register, NHS Economic Evaluation Database, Health Technology Assessment Database. The bibliographies of retrieved papers and content experts were consulted for additional references.

SELECTION CRITERIA

All eligible randomised controlled trials (RCTs) were included. No unpublished RCTs were included in this edition of the review.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by two reviewers. A validated checklist was used to score the quality of the RCTs. Comparable trials were pooled using fixed effects model.

MAIN RESULTS

Twenty-six RCTs were included. The comparators were placebo, diclofenac, ibuprofen, naproxen, nimesulide, nabumetone, paracetamol, celecoxib and Arthrotec. The evidence reviewed indicated that rofecoxib was more effective than placebo (patient global response RR 1.75 95% CI: 1.35, 2.26) but was associated with more adverse events (RR 1.32 95% CI 1.11, 1.56). There were no consistent differences in efficacy between rofecoxib and any of the active comparators at equivalent doses. Endoscopic studies indicated that compared to ibuprofen 800 mg three times a day, rofecoxib caused fewer erosions and gastric ulcers at doses of 25mg and 50mg; the difference in duodenal ulcers was evident only at a dose of 25mg. Rofecoxib 50mg also caused more endoscopically observed ulcers greater than rofecoxib 25mg (RR 2.48 CI: 1.21, 5.11). Very few of the trials reported overall rates of GI adverse events although rofecoxib was found to cause fewer GI events than naproxen. Only one of the nine trials comparing rofecoxib to celecoxib reported on the overall rates of GI events and this was a comparison of the higher recommended dose of rofecoxib with the lower recommended dose of celecoxib. Similarly, the three trials in older hypertensive patients that examined the cardiovascular safety of rofecoxib and celecoxib used non-comparable doses; the results of these studies indicated that rofecoxib caused more patients to have oedema and a clinically significant increase in systolic blood pressure. This difference between rofecoxib and celecoxib was not evident in studies conducted in more general populations.

AUTHORS' CONCLUSIONS

Rofecoxib was voluntarily withdrawn from global markets in October 2004 therefore there are no implications for practice concerning its use. There remains a number of questions over both the benefits and risks associated with Cox II selective agents and further work is ongoing.

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

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

Treating Osteoarthritis With Cyclooxygenase-2–Specific Inhibitors

Osteoarthritis and hypertension are highly prevalent among older Americans. Anti-inflammatory medications can destabilize blood pressure control. We estimated the decreased cardiovascular risk, premature mortality, and direct health care costs that could be avoided if blood pressure control is not destabilized among hypertensive Americans taking cyclooxygenase-2 (COX-2)-specific inhibitors for osteoarthritis. Data from the Third National Health and Nutrition Examination Survey (NHANES III) provided the distribution of cardiovascular risk factors among American adults with osteoarthritis and hypertension. The Cardiovascular Disease Life Expectancy Model was used to estimate the impact of a 2.26% increase in systolic blood pressure on the basis of results of a randomized trial comparing COX-2-specific inhibitors. A similar analysis was completed for American adults with osteoarthritis and untreated hypertension (> or =140/90 mm Hg). Among 7.3 million Americans with treated hypertension, maintaining blood pressure control would avoid >30,000 stroke deaths and 2,000 coronary deaths resulting in >449,000 person years of life saved and 1.4 billion dollars in direct health care cost savings. When an additional 3.8 million Americans with untreated hypertension are considered, maintaining blood pressure control could prevent >47,000 stroke deaths, 39,000 coronary deaths, and result in 668,000 person years of life saved and >2.4 billion dollars in direct health care cost savings. We conclude that even a small increase in systolic blood pressure among hypertensive Americans with osteoarthritis may substantially increase the clinical and economic burden of cardiovascular disease. Maintaining blood pressure control may be associated with substantial benefits.

Comparison of the COX-inhibiting nitric oxide donator AZD3582 and rofecoxib in treating the signs and symptoms of Osteoarthritis of the knee

OBJECTIVE

To compare the efficacy, safety, and tolerability of AZD3582 with that of rofecoxib, naproxen, and placebo in patients with osteoarthritis (OA) of the knee, and to define the dosage of AZD3582 (125 mg, 375 mg, and 750 mg twice a day) that is noninferior in efficacy to rofecoxib.

METHODS

A double-blind study of 672 patients with OA of the knee was conducted. Patients who experienced increased pain on withdrawal of analgesia were randomized to receive AZD3582 125 mg, 375 mg, or 750 mg twice a day; rofecoxib 25 mg once a day; naproxen 500 mg twice a day; or placebo for 6 weeks. Efficacy, tolerability, and safety were monitored throughout the study. The primary variable was the change in Western Ontario and McMaster Universities Osteoarthritis Index pain subscale from baseline to the mean of weeks 4 and 6, comparing AZD3582 with placebo for superiority and with rofecoxib for noninferiority using a predefined margin of 10 mm.

RESULTS

For the primary variable, AZD3582 375 mg and 750 mg were superior to placebo (least squares mean difference [95% confidence interval] -12 mm [-18, -6], P < 0.001 and -13 mm [-19, -7], P < 0.001, respectively) and were noninferior to rofecoxib (-2 mm [-8, 4], P < 0.001 and -3 mm [-9, 3], P < 0.001, respectively). AZD3582 125 mg was not significantly different from placebo for the primary variable.

CONCLUSION

AZD3582 375 mg and 750 mg twice a day were superior to placebo and as effective as rofecoxib 25 mg/day in treating the signs and symptoms of OA of the knee. AZD3582 125 mg twice a day was not statistically different from placebo.

A Medicare database review found that physician preferences increasingly outweighed patient characteristics as determinants of first-time prescriptions for COX-2 inhibitors

OBJECTIVE

Although innovative drugs may be underprescribed by some physicians, it is possible that rapid adoption after market introduction may lead to prescribing such drugs to patients without a clear indication. We sought to quantify the relative contributions of patient vs. physician factors to the decision to prescribe selective cyclooxygenase-2 (COX-2) inhibitors during the first 2 years of their availability.

METHODS

A cohort of 37,957 Medicare beneficiaries who were enrolled in the Pharmaceutical Assistance Contract for the Elderly in Pennsylvania was identified. All patients had started using nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) or selective COX-2 inhibitors between January 1, 1999, and December 31, 2000, and had no prior NSAID use. All had full prescription drug coverage, including NSAIDs and selective COX-2 inhibitors. Subsequent prescriptions were not considered. We quantified the amount of variation in first-time COX-2 prescribing that could be explained by predictors of gastrointestinal (GI) toxicity, other patient characteristics, or physician preferences. Explained variation was calculated as the R(2) (standardized to range from 0 to 1) from unconditional logistic regression and random intercept mixed effects logistic regression, fitted separately in each of eight consecutive 3-month periods.

RESULTS

COX-2 inhibitors were adopted as the preferred NSAID by 55% of physicians within 180 days after they were marketed. In new NSAID users, COX-2 prescribing was twice as dependent on physician prescribing preferences (R(2)=60%) as on the combined predictors of GI toxicity (R(2)=3%) and other patient factors (R(2)=30%). The ratio of COX-2 prescribing explained by physician preferences over the contribution of patient factors increased from 2 to more than 10 over a 24-month period.

CONCLUSIONS

First-time COX-2 inhibitor prescribing was somewhat dependent on patient factors in the first quarter of marketing, but the proportional influence of physician preferences increased substantially over the following 2 years, raising the question of why physician factors and not patient risk factors influence COX-2 inhibitor prescribing.

Cyclooxygenases: new forms, new inhibitors, and lessons from the clinic

The beneficial actions of nonsteroidal anti-inflammatory drugs (NSAIDs) have been linked to their ability to inhibit inducible COX-2 at sites of inflammation, and their side effects (e.g., gastric damage) to inhibition of constitutive COX-1. Selective inhibitors of COX-2, such as celecoxib, etoricoxib, lumiracoxib, rofecoxib, and valdecoxib have been developed and the greatest recent growth in our knowledge in this area has been come from the clinical use of these compounds. Although clinical data indicate that COX-2 selectivity is associated with a reduction in severe gastrointestinal events, they also reveal there are roles for constitutive COX-2 within tissues such as the brain, kidney, pancreas, intestine, and blood vessels. We now better understand the roles of COX-1 and COX-2 in functions as disparate as the perception of pain and the progression of cancers. Clinical use of COX-2-selective compounds has ignited strong debates regarding potential side effects, most notably those within the cardiovascular system such as myocardial infarctions, strokes, and elevation in blood pressure. This review will discuss how the latest studies help us understand the roles of COX-1 and COX-2 and what clinically proven benefits the newer generation of COX-2-selective inhibitors offer

Comparison of lumiracoxib with naproxen and ibuprofen in the Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET), cardiovascular outcomes: randomised controlled trial

BACKGROUND

The potential for cyclo-oxygenase 2 (COX2)-selective inhibitors to increase the risk for myocardial infarction is controversial. The Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET) aimed to assess gastrointestinal and cardiovascular safety of the COX2 inhibitor lumiracoxib compared with two non-steroidal anti-inflammatory drugs, naproxen and ibuprofen.

METHODS

18325 patients age 50 years or older with osteoarthritis were randomised to lumiracoxib 400 mg once daily (n=9156), naproxen 500 mg twice daily (4754), or ibuprofen 800 mg three times daily (4415) in two substudies of identical design. Randomisation was stratified for low-dose aspirin use and age. The primary cardiovascular endpoint was the Antiplatelet Trialists' Collaboration endpoint of non-fatal and silent myocardial infarction, stroke, or cardiovascular death. Analysis was by intention to treat.

FINDINGS

81 (0.44%) patients did not start treatment and 7120 (39%) did not complete the study. At 1-year follow-up, incidence of the primary endpoint was low, both with lumiracoxib (59 events [0.65%]) and the non-steroidal anti-inflammatory drugs (50 events [0.55%]; hazard ratio 1.14 [95% CI 0.78-1.66], p=0.5074). Incidence of myocardial infarction (clinical and silent) in the overall population in the individual substudies was 0.38% with lumiracoxib (18 events) versus 0.21% with naproxen (ten) and 0.11% with lumiracoxib (five) versus 0.16% with ibuprofen (seven). In the naproxen substudy, rates of myocardial infarction (clinical and silent) did not differ significantly compared with lumiracoxib in the population not taking low-dose aspirin (hazard ratio 2.37 [95% CI 0.74-7.55], p=0.1454), overall (1.77 [0.82-3.84], p=0.1471), and in patients taking aspirin (1.36 [0.47-3.93], p=0.5658). In the ibuprofen substudy, these rates did not differ between lumiracoxib and ibuprofen in the population not taking low-dose aspirin (0.75 [0.20-2.79], p=0.6669), overall (0.66 [0.21-2.09], p=0.4833), and in patients taking aspirin (0.47 [0.04-5.14], p=0.5328).

INTERPRETATION

The primary endpoint, including incidence of myocardial infarction, did not differ between lumiracoxib and either ibuprofen or naproxen, irrespective of aspirin use. This finding suggests that lumiracoxib is an appropriate treatment for patients with osteoarthritis, who are often at high cardiovascular risk and taking low-dose aspirin.

Relationship between COX-2 specific inhibitors and hypertension

There is controversy whether cyclooxygenase-2 (COX-2) specific inhibitors are associated with elevations in blood pressure requiring treatment in typical clinical practice. We examined the risk of new onset hypertension in a retrospective case-control study involving 17 844 subjects aged > or =65 years from 2 US states. Multivariable logistic models were examined to assess the relative risk of new onset hypertension requiring treatment in patients who used celecoxib or rofecoxib compared with patients taking either the other COX-2 specific inhibitor, a nonspecific NSAID, or no NSAID. During the 1999 to 2000 study period, 3915 patients were diagnosed and began treatment for hypertension; 4 controls were selected for every case. In no model was celecoxib significantly associated with the development of hypertension. Rofecoxib users were at a significantly increased relative risk of new onset hypertension compared with patients taking celecoxib (odds ratio [OR] 1.6; 95% confidence interval [CI], 1.2 to 2.1), taking a nonspecific NSAID (OR 1.4; 95% CI, 1.1 to 1.9), or taking no NSAID (OR 1.6; 95% CI, 1.3 to 2.0). There were no clear dosage or duration effects. In patients with a history of chronic renal disease, liver disease, or congestive heart failure, the relative risk of new onset hypertension was twice as high in those taking rofecoxib compared with celecoxib (OR 2.1; 95% CI, 1.0 to 4.3). In this retrospective case-control study of patients aged > or =65 years, rofecoxib use was associated with an increased relative risk of new onset hypertension; this was not seen in patients taking celecoxib.

Cyclo-oxygenase-2 inhibitors versus non-selective non-steroidal anti-inflammatory drugs and congestive heart failure outcomes in elderly patients: a population-based cohort study

BACKGROUND

Non-selective, non-steroidal anti-inflammatory drugs (NSAIDs) are associated with an increased risk of congestive heart failure, but little is known about the cardiovascular effects of a newer group of NSAIDS called selective cyclo-oxygenase (COX)-2 inhibitors. We aimed to compare rates of admission for congestive heart failure in elderly patients who were newly dispensed COX-2 inhibitors or non-selective NSAIDs.

METHODS

In this population-based retrospective cohort study we identified NSAID-naive individuals aged 66 years or older, who were started on rofecoxib (n=14,583), celecoxib (n=18,908), and non-selective NSAIDs (n=5,391), and randomly selected non-NSAID users as controls (n=100,000).

FINDINGS

Relative to non-NSAID users, patients on rofecoxib and non-selective NSAIDS had an increased risk of admission for congestive heart failure (adjusted rate ratio 1.8, 95% CI 1.5-2.2, and 1.4, 1.0-1.9, respectively), but not celecoxib (1.0, 0.8-1.3). Compared with celecoxib users, admission was significantly more likely in users of non-selective NSAIDs (1.4, 1.0-1.9) and rofecoxib (1.8, 1.4-2.4). Risk of admission for rofecoxib users was higher than that for non-selective NSAID users (1.5, 1.1-2.1). Of patients with no admission in the past 3 years, only rofecoxib users were at increased risk of subsequent admission relative to controls (1.8, 1.4-2.3).

INTERPRETATION

These findings suggest a higher risk of admission for congestive heart failure in users of rofecoxib and non-selective NSAIDs, but not celecoxib, relative to non-NSAID controls.

Relationship Between Selective Cyclooxygenase-2 Inhibitors and Acute Myocardial Infarction in Older Adults

Background— Although cyclooxygenase-2 inhibitors (coxibs) were developed to cause less gastrointestinal hemorrhage than nonselective nonsteroidal antiinflammatory drugs (NSAIDs), there has been concern about their cardiovascular safety. We studied the relative risk of acute myocardial infarction (AMI) among users of celecoxib, rofecoxib, and NSAIDs in Medicare beneficiaries with a comprehensive drug benefit.

Methods and Results— We conducted a matched case-control study of 54 475 patients 65 years of age or older who received their medications through 2 state-sponsored pharmaceutical benefits programs in the United States. All healthcare use encounters were examined to identify hospitalizations for AMI. Each of the 10 895 cases of AMI was matched to 4 controls on the basis of age, gender, and the month of index date. We constructed matched logistic regression models including indicators for patient demographics, healthcare use, medication use, and cardiovascular risk factors to assess the relative risk of AMI in patients who used rofecoxib compared with persons taking no NSAID, taking celecoxib, or taking NSAIDs. Current use of rofecoxib was associated with an elevated relative risk of AMI compared with celecoxib (odds ratio [OR], 1.24; 95% CI, 1.05 to 1.46; P =0.011) and with no NSAID (OR, 1.14; 95% CI, 1.00 to 1.31; P =0.054). The adjusted relative risk of AMI was also elevated in dose-specific comparisons: rofecoxib ≤25 mg versus celecoxib ≤200 mg (OR, 1.21; 95% CI, 1.01 to 1.44; P =0.036) and rofecoxib >25 mg versus celecoxib >200 mg (OR, 1.70; 95% CI, 1.07 to 2.71; P =0.026). The adjusted relative risks of AMI associated with rofecoxib use of 1 to 30 days (OR, 1.40; 95% CI, 1.12 to 1.75; P =0.005) and 31 to 90 days (OR, 1.38; 95% CI, 1.11 to 1.72; P =0.003) were higher than >90 days (OR, 0.96; 95% CI, 0.72 to 1.25; P =0.8) compared with celecoxib use of similar duration. Celecoxib was not associated with an increased relative risk of AMI in these comparisons.

Conclusions— In this study, current rofecoxib use was associated with an elevated relative risk of AMI compared with celecoxib use and no NSAID use. Dosages of rofecoxib >25 mg were associated with a higher risk than dosages ≤25 mg. The risk was elevated in the first 90 days of use but not thereafter.

Effects of COX Inhibition on Blood Pressure and Kidney Function in ACE Inhibitor-Treated Blacks and Hispanics

Cyclo-oxygenase (COX) inhibitors attenuate the antihypertensive effects of angiotensin-converting enzyme (ACE) inhibitors and reduce kidney function. The study tests the hypothesis that these two classes of drugs have similar effects on glomerular filtration rate (GFR) and 24-hour blood pressure. The primary endpoint was change in 24-hour systolic blood pressure. Using a randomized crossover design, 25 black and Hispanic hypertensive participants (mean age 58+/-3 years) with osteoarthritis were studied. All participants received an ACE inhibitor at baseline. Once systolic blood pressure was <140 mm Hg, either celecoxib 200 mg/d or diclofenac 75 mg twice daily for 4 weeks was started. After measurements were obtained, all participants underwent a 2-week washout period and crossed over to the other drug for 4 weeks. A significant difference in mean 24-hour systolic blood pressure was noted between groups at 4 weeks (+4.1+/-1.1 mm Hg diclofenac versus +0.6+/-0.6 mm Hg celecoxib; P=0.01). However, because celecoxib has duration of action shorter than 24 hours, we compared ambulatory values at celecoxib trough and peak activities. At peak, no difference in systolic blood pressure was noted between agents (+3.6+/-0.04 mm Hg diclofenac versus +4.2+/-1.9 mm Hg celecoxib; P=0.67). GFR was also differentially affected at 24 hours (-9.9+/-2.4 mL/min diclofenac versus -0.4+/-1.2 mL/min celecoxib; P=0.01). We conclude that diclofenac and celecoxib increase systolic blood pressure at peak levels; however, these agents differ in their 24-hour effects. Differences observed in blood pressure response between COX inhibitors may not be related in their sensitivity but rather their dosing frequency.

Blood Pressure Elevation with Rofecoxib in Older Adults

Objective:

To report blood pressure elevation associated with rofecoxib use in 2 older adults.

Case Summaries:

Two patients, aged 75 and 94 years, were prescribed rofecoxib for osteoarthritis pain. After the initiation of therapy, an elevation in systolic blood pressure measurement ≥17 mm Hg was observed. Upon withdrawal of rofecoxib, blood pressure in one patient returned to baseline measurements. In the second patient, sustained rofecoxib use resulted in blood pressure elevation and change in antihypertensive therapy.

Discussion:

It is well known that even a small elevation in blood pressure can significantly increase a person's risk for cardiovascular events. However, little is known about the potential magnitude of blood pressure elevation with the use of cyclooxygenase-2 inhibitors in the older adult population. In 2 older adults with osteoarthritis and hypertension, rofecoxib potentially led to a substantial elevation in blood pressure. In each case, adjustments of respective therapeutic regimens were made. The Naranjo probability scale indicates a probable relationship in both cases between the rofecoxib and blood pressure elevation.

Conclusions:

These reports suggest that rofecoxib could produce greater elevation in blood pressure in older hypertensive adults than has been previously reported. Therefore, close monitoring of blood pressure for 1–2 months after initiation of rofecoxib therapy is advisable. Further study is needed to determine the true clinical significance of these findings in older hypertensive adults.

Anaesthesia and postoperative analgesia in older patients with chronic obstructive pulmonary disease: special considerations

Chronic obstructive pulmonary disease (COPD) and older age are known to be independent risk factors for severe perioperative adverse outcomes after surgery. A basic understanding of the disease, careful preoperative evaluation and preparation of the patient, as well as a tailored anaesthetic management plan might help to decrease complications in this patient population. Aging affects the pharmacokinetics and pharmacodynamics of almost all drugs and therefore the dosage must be adapted in older patients. The type of anaesthesia (general versus regional anaesthesia) has no substantial effect on perioperative morbidity and mortality. Most patients, even with severe COPD, tolerate general anaesthesia without major problems. One important goal of the anaesthetic management is to prevent reflex-induced bronchoconstriction, which can be accomplished by the use of volatile anaesthetics. Early recovery can be facilitated by the use of short-acting drugs, such as propofol and the new opioid remifentanil. Judicious use of neuromuscular blocking agents is necessary because of the risk of residual paralysis, and those agents associated with histamine liberation should be avoided. Ventilation requires long expiration times to avoid air trapping, and hyperinflation to avoid the possible threat of pneumothorax and a decrease in cardiac output. For postoperative analgesia, a balanced regimen consisting of regional analgesia with local anaesthetics and NSAIDs should be preferred. This will enhance analgesia and reduce opioid toxicity, which is important in patients with COPD, where respiratory depression is especially dangerous.

Renal Cyclooxygenase-2 (Cox-2)

BACKGROUND/AIMS

The role of COX-2 for renal function during renal development, for physiology and pathophysiology of renal diseases and the side effects of available COX-2 inhibitors, has gained increasing interest. We aimed therefore to review the respective role of renal COX-2.

METHODS

Review of relevant recent publications in the field, and in addition of in part unpublished data obtained in our laboratories.

RESULTS

COX-2 is 'constitutively' localized in the kidney i.e. in macula densa, TALH, interstitial cells, and is of utmost importance for normal renal development. Renal COX-2 is regulated by for example sodium and volume intake, angiotensin II, glucocorticoids often involving specific COX-2 promotor response elements. COX-2 derived prostanoids are required for preservation of renal blood flow and glomerular filtration especially in states of fluid deficit, they promote natriuresis, and furthermore may stimulate renin secretion during low-sodium intake/loop diuretic use. Conversely, COX-2 inhibitors decrease glomerular filtration, and renal perfusion, sometimes even causing acute renal failure. In addition, COX-2 inhibitors cause sodium retention, edema formation, cardiac failure and hypertension. The role of COX-2 derived prostanoids in renal inflammation or failure including diabetic nephropathy and renal transplantation remains at present controversial.

CONCLUSION

COX-2 is one of the major players in renal physiology and pathophysiology. One focus of future work should be placed on COX-2 in primary renal diseases.

Cyclooxygenases, the kidney, and hypertension

Selective cyclooxygenase (COX)-2 inhibitors that are in widespread clinical use were developed to avoid side effects of conventional NSAIDs, including gastrointestinal and renal toxicity. However, COX-2 is constitutively expressed in the kidney and is highly regulated in response to alterations in intravascular volume. COX-2 metabolites have been implicated in maintenance of renal blood flow, mediation of renin release, and regulation of sodium excretion. COX-2 inhibition may transiently decrease urine sodium excretion in some subjects and induce mild to moderate elevation of blood pressure. Furthermore, in conditions of relative intravascular volume depletion and/or renal hypoperfusion, interference with COX-2 activity can have deleterious effects on maintenance of renal blood flow and glomerular filtration rate. In addition to physiological regulation of COX-2 expression in the kidney, increased renal cortical COX-2 expression is seen in experimental models associated with altered renal hemodynamics and progressive renal injury (decreased renal mass, poorly controlled diabetes), and long-term treatment with selective COX-2 inhibitors ameliorates functional and structural renal damage in these conditions.

Spontaneous Reports of Hypertension Leading to Hospitalisation in Association with Rofecoxib, Celecoxib, Nabumetone and Oxaprozin

BACKGROUND AND OBJECTIVE

Data on file with the US FDA, and other published studies, suggest that the selective cyclo-oxygenase (COX)-2 inhibitor NSAID rofecoxib has a greater hypertensive adverse effect than other NSAIDs, including celecoxib. In this study we describe a pharmacoepidemiologic analysis of spontaneous adverse event reports of acute, clinically serious hypertension (as defined by hospitalisation) reported in association with rofecoxib, celecoxib, nabumetone and oxaprozin. The objective of this analysis is to assess whether postmarketing data are consistent with results of clinical trials. We also collapse cases into series for the identification of possible risk factors for clinically severe, NSAID-associated hypertension.

METHODS

Domestic (US) cases of apparently unconfounded, acute hypertension leading to hospitalisation were collected and reviewed from the spontaneous adverse events database of the FDA for rofecoxib, celecoxib, nabumetone and oxaprozin for the initial 3 years of marketing. Drug use data for the same intervals enabled calculation of reporting rates.

RESULTS

In an analysis of reporting rates, hospitalisation for acute blood pressure (BP) elevation was reported more frequently (3.8-fold) for rofecoxib compared with celecoxib. A total of 34 cases are collapsed into case series. No cases were identified for either nabumetone or oxaprozin. Inspection of reviewed cases for celecoxib and rofecoxib suggest that these patients (average age 72 years) were potentially high-risk candidates for NSAID therapy.

DISCUSSION AND CONCLUSION

During early marketing, hospitalisation for acute BP elevation appears to have been reported more frequently for rofecoxib compared with celecoxib. This is consistent with clinical trial data on file with the FDA, and other published studies that found rofecoxib to have a greater effect on BP than other NSAIDs, including celecoxib. This finding may be particularly relevant in older patients given the prevalence of hypertension and cardiovascular disease in this age group.

Unexpected Nanomolar Inhibition of Carbonic Anhydrase by COX-2-Selective Celecoxib: New Pharmacological Opportunities Due to Related Binding Site Recognition

By optimizing binding to a selected target protein, modern drug research strives to develop safe and efficacious agents for the treatment of disease. Selective drug action is intended to minimize undesirable side effects from scatter pharmacology. Celecoxib (Celebrex), valdecoxib (Bextra), and rofecoxib (Vioxx) are nonsteroidal antiinflammatory drugs (NSAIDs) due to selective inhibition of inducible cyclooxygenase COX-2 while sparing inhibition of constitutive COX-1. While rofecoxib contains a methyl sulfone constituent, celecoxib and valdecoxib possess an unsubstituted arylsulfonamide moiety. The latter group is common to many carbonic anhydrase (CA) inhibitors. Using enzyme kinetics and X-ray crystallography, we demonstrate an unexpected nanomolar affinity of the COX-2 specific arylsulfonamide-type celecoxib and valdecoxib for isoenzymes of the totally unrelated carbonic anhydrase (CA) family, such as CA I, II, IV, and IX, whereas the rofecoxib methyl sulfone-type has no effect. When administered orally to glaucomatous rabbits, celecoxib and valdecoxib lowered intraocular pressure, suggesting that these agents may have utility in the treatment of this disorder. The crystal structure of celecoxib in complex with CA II reveals part of this inhibition to be mediated via binding of the sulfonamide group to the catalytic zinc of CA II. To investigate the structural basis for cross-reactivity of these compounds between COX-2 and CA II, we compared the molecular recognition properties of both protein binding pockets in terms of local physicochemical similarities among binding site-exposed amino acids accommodating different portions of the drug molecules. Our approach Cavbase, implemented into Relibase, detects similarities between the sites, suggesting some potential to predict unexpected cross-reactivity of drugs among functionally unrelated target proteins. The observed cross-reactivity with CAs may also contribute to differences in the pharmacological profiles, in particular with respect to glaucoma and anticancer therapy and may suggest new opportunities of these COX-2 selective NSAIDs.

Potential cardiovascular effects of COX-2 selective nonsteroidal antiinflammatory drugs

The newly developed nonsteroidal antiinflammatory drugs (NSAIDs) that selectively inhibit cyclooxygenase-2 (COX-2), are effective against pain and inflammation and appear to have less gastrointestinal toxicity than conventional NSAIDs. Their COX-2 selectivity, however, has raised concerns regarding their cardiovascular safety, since they do not inhibit COX-1, the isoform of the enzyme that is active in thrombosis and vasoconstriction. At this point there is no conclusive evidence that COX-2 inhibitors cause ischemic vascular events, because retrospective post hoc analyses conflict one another, and no specific randomized trials have yet been done. Renal effects, edema and hypertension appear to be similar between conventional NSAIDs and COX-2-selective inhibitors. Aspirin is still required for patients with cardiovascular risk who are prescribed a COX-2-selective inhibitor.

Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

The National High Blood Pressure Education Program presents the complete Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Like its predecessors, the purpose is to provide an evidence-based approach to the prevention and management of hypertension. The key messages of this report are these: in those older than age 50, systolic blood pressure (BP) of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP; beginning at 115/75 mm Hg, CVD risk doubles for each increment of 20/10 mm Hg; those who are normotensive at 55 years of age will have a 90% lifetime risk of developing hypertension; prehypertensive individuals (systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg) require health-promoting lifestyle modifications to prevent the progressive rise in blood pressure and CVD; for uncomplicated hypertension, thiazide diuretic should be used in drug treatment for most, either alone or combined with drugs from other classes; this report delineates specific high-risk conditions that are compelling indications for the use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); two or more antihypertensive medications will be required to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg) for patients with diabetes and chronic kidney disease; for patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using two agents, one of which usually will be a thiazide diuretic, should be considered; regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan. Positive experiences, trust in the clinician, and empathy improve patient motivation and satisfaction. This report serves as a guide, and the committee continues to recognize that the responsible physician's judgment remains paramount.

Comparison of Changes in Blood Pressure Measurements and Antihypertensive Therapy in Older, Hypertensive, Ambulatory Care Patients Prescribed Celecoxib or Rofecoxib

STUDY OBJECTIVE

To determine if changes in blood pressure and changes in class or dosing of antihypertensive drugs were significantly different in patients treated with celecoxib versus rofecoxib, two cyclooxygenase (COX)-2 inhibitors.

DESIGN

Retrospective cohort study.

SETTING

Thirty-one ambulatory care practices that shared an electronic medical record.

PATIENTS

Nine hundred sixty men and women over age 55 years with stable hypertension.

INTERVENTION

Patients had to have at least a 30-day supply of celecoxib or rofecoxib (any dose) prescribed between July 1, 1999, and June 30, 2000.

MEASUREMENTS AND MAIN RESULTS

Patients were followed for 6 months, and logistic regression and survival models were used to compare outcomes between groups while adjusting for confounders. Baseline characteristics of 517 patients receiving celecoxib and 443 receiving rofecoxib were similar. No significant differences were observed, regardless of the COX-2 inhibitor prescribed, in the proportion of patients whose systolic blood pressure increased by 20 mm Hg, whose diastolic blood pressure increased by 15 mm Hg, or who were prescribed a new class of antihypertensive drug. Compared with patients taking celecoxib, those taking rofecoxib were significantly more likely (odds ratio 1.68, 95% confidence interval 1.09-2.60) to have had the dosage of their antihypertensive drug increased and also the dosage increased sooner (p<0.05). New-onset cardiac and renal comorbidity, number of physician visits, and changes in body weight and laboratory values were not significantly different between the groups.

CONCLUSION

No significant differences in blood pressure changes or in the proportion of patients who were prescribed a new class of antihypertensive drug were found between rofecoxib- and celecoxib-treated patients. However, significantly more rofecoxib-treated patients had the dosage of their existing antihypertensive drug increased compared with those receiving celecoxib.

Calcium channel blocker-related periperal edema: can it be resolved?

Calcium channel blocker (CCB)-related edema is quite common in clinical practice and can effectively deter a clinician from continued prescription of these drugs. Its etiology relates to a decrease in arteriolar resistance that goes unmatched in the venous circulation. This disproportionate change in resistance increases hydrostatic pressures in the precapillary circulation and permits fluid shifts into the interstitial compartment. CCB-related edema is more common in women and relates to upright posture, age, and the choice and dose of the CCB. Once present it can be slow to resolve without intervention. A number of strategies exist to treat CCB-related edema, including switching CCB classes, reducing the dosage, and/or adding a known venodilator such as a nitrate, an angiotensin-converting enzyme inhibitor, or an angiotensin-receptor blocker to the treatment regimen. Angiotensin-converting enzyme inhibitors have been best studied in this regard. Diuretics may alter the edema state somewhat, but at the expense of further reducing plasma volume. Traditional measures such as limiting the amount of time that a patient is upright and/or considering use of graduated compression stockings are useful adjunctive therapies. Discontinuing the CCB and switching to an alternative antihypertensive therapy will resolve the edema.

The development of COX2 inhibitors

Aspirin, arguably the world's favourite drug, has been around since the late nineteenth century, but it wasn't until the late 1970s that its ability to inhibit prostaglandin production by the cyclooxygenase enzyme was identified as the basis of its therapeutic action. Early hints of a second form of the cyclooxygenase that was differentially sensitive to other aspirin-like drugs ultimately ushered in an exciting era of drug discovery, culminating in the introduction of an entirely new generation of anti-inflammatories. This article reviews the story of this discovery and looks at the future of cyclooxygenase pharmacology.

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.