The safety profile, tolerability, and effective dose range of rofecoxib in the treatment of rheumatoid arthritis. Phase II Rofecoxib Rheumatoid Arthritis Study Group

Rheumatiod Arthritis: An Updated Overview of Latest Therapy and Drug Delivery

Rheumatoid arthritis is a severe autoimmune disorder, related to joints. It is associated with serious cartilage destruction. This causes disability and reduces the excellence of life. Numerous treatments are existed to combat this disease, however, they are not very efficient and possess severe side effects, higher doses, and frequent administration. Therefore, newer therapies are developed to overcome all these limitations. These include different monoclonal antibodies, immunoglobulins, small molecules used for immunotherapy and transgenes for gene therapy. One of the main goals of these new generation therapeutics is to address the underlying distressing biological processes by specifically targeting the causative agents with fewer systemic side effects and greater patient console. It is very fortuitous that loads of progressive investigations are going on in this field and many of them have entered into the successful clinical trial. But till date, a limited molecule has got FDA clearance and entered the market for treating this devastating disease. This review highlights the overview of conventional therapy and advancements in newer therapeutics including immunotherapy and gene therapy for rheumatoid arthritis. Further, different novel techniques for the delivery of these therapeutics of active and passive targeting are also described.

Force Fields for Small Molecules

Molecular dynamics (MD) simulations have been widely applied to computer-aided drug design (CADD). While MD has been used in a variety of applications such as free energy perturbation and long-time simulations, the accuracy of the results from those methods depends strongly on the force field used. Force fields for small molecules are crucial, as they not only serve as building blocks for developing force fields for larger biomolecules but also act as model compounds that will be transferred to ligands used in CADD. Currently, a wide range of small molecule force fields based on additive or nonpolarizable models have been developed. While these nonpolarizable force fields can produce reasonable estimations of physical properties and have shown success in a variety of systems, there is still room for improvements due to inherent limitations in these models including the lack of an electronic polarization response. For this reason, incorporating polarization effects into the energy function underlying a force field is believed to be an important step forward, giving rise to the development of polarizable force fields. Recent simulations of biological systems have indicated that polarizable force fields are able to provide a better physical representation of intermolecular interactions and, in many cases, better agreement with experimental properties than nonpolarizable, additive force fields. Therefore, this chapter focuses on the development of small molecule force fields with emphasis on polarizable models. It begins with a brief introduction on the importance of small molecule force fields and their evolution from additive to polarizable force fields. Emphasis is placed on the additive CHARMM General Force Field and the polarizable force field based on the classical Drude oscillator. The theory for the Drude polarizable force field and results for small molecules are presented showing their improvements over the additive model. The potential importance of polarization for their application in a wide range of biological systems including CADD is then discussed.

Application of liposomes in treatment of rheumatoid arthritis: quo vadis

The most common treatments for rheumatoid arthritis include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease modifying antirheumatic drugs (DMARDs), and some biological agents. However, none of the treatments available is able to achieve the ultimate goal of treatment, that is, drug-free remission. This limitation has shifted the focus of treatment to delivery strategies with an ability to deliver the drugs into the synovial cavity in the proper dosage while mitigating side effects to other tissues. A number of approaches like microemulsions, microspheres, liposomes, microballoons, cocrystals, nanoemulsions, dendrimers, microsponges, and so forth, have been used for intrasynovial delivery of these drugs. Amongst these, liposomes have proven to be very effective for retaining the drug in the synovial cavity by virtue of their size and chemical composition. The fast clearance of intra-synovially administered drugs can be overcome by use of liposomes leading to increased uptake of drugs by the target synovial cells, which in turn reduces the exposure of nontarget sites and eliminates most of the undesirable effects associated with therapy. This review focuses on the use of liposomes in treatment of rheumatoid arthritis and summarizes data relating to the liposome formulations of various drugs. It also discusses emerging trends of this promising technology.

Current perspectives in NSAID-induced gastropathy

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most highly prescribed drugs in the world. Their analgesic, anti-inflammatory, and antipyretic actions may be beneficial; however, they are associated with severe side effects including gastrointestinal injury and peptic ulceration. Though several approaches for limiting these side effects have been adopted, like the use of COX-2 specific drugs, comedication of acid suppressants like proton pump inhibitors and prostaglandin analogs, these alternatives have limitations in terms of efficacy and side effects. In this paper, the mechanism of action of NSAIDs and their critical gastrointestinal complications have been reviewed. This paper also provides the information on different preventive measures prescribed to minimize such adverse effects and analyses the new suggested strategies for development of novel drugs to maintain the anti-inflammatory functions of NSAIDs along with effective gastrointestinal protection.

Efficacy and safety of celecoxib versus diclofenac and omeprazole in elderly arthritis patients: a subgroup analysis of the CONDOR trial

OBJECTIVE

To compare the safety and efficacy of celecoxib versus diclofenac slow release (SR) plus omeprazole in elderly arthritis patients.

RESEARCH DESIGN AND METHODS

Patients aged≥65 years, with osteoarthritis and/or rheumatoid arthritis, at high gastrointestinal (GI) risk who participated in the CONDOR trial (Celecoxib vs. Omeprazole and Diclofenac in Patients With Osteoarthritis and Rheumatoid Arthritis) were included in this subanalysis. CONDOR was a 6-month prospective, double-blind, randomized, parallel-group, multicenter, international study comparing treatment with celecoxib 200 mg twice daily (BID) versus diclofenac SR 75 mg BID plus omeprazole 20 mg daily.

MAIN OUTCOME MEASURES

The primary end point was a composite of Clinically Significant Upper and Lower GI Events adjudicated by an independent blinded expert committee. Efficacy was determined by the Patient's Global Assessment of Arthritis.

RESULTS

A total of 2446 patients aged≥65 years were included in the intent-to-treat (ITT) population (n=1219 celecoxib; n=1227 diclofenac). Eight patients in the celecoxib group and 52 in the diclofenac group were adjudicated as having Clinically Significant Upper and Lower GI events (adjusted odds ratio: 6.27; p<0.0001). Clinically significant reductions in hemoglobin (≥2 g/dL) and/or hematocrit (≥10%) were observed in 23 patients in the celecoxib group and in 76 in the diclofenac group (relative risk: 3.22 [95% confidence interval: 2.04-5.07]; p<0.0001). Incidence of moderate-to-severe abdominal symptoms and discontinuation of treatment due to GI adverse events (AEs) were lower in the celecoxib group. The Patient's Global Assessment of Arthritis score least squares mean change from baseline to final visit and percentage of patients rating treatment efficacy as good/very good at baseline and final visit were similar in both groups.

LIMITATIONS

The dose of celecoxib used is consistent with the European label for the management of osteoarthritis and may not reflect what is commonly prescribed in current clinical practice in the United States. The data were obtained in a clinical trial setting where patients were enrolled based on specific inclusion and exclusion criteria; as such, the patients may not be broadly representative of the patient population in a general practice setting.

CONCLUSIONS

Efficacy was comparable in the two treatment groups. There were fewer endpoints as well as fewer GI AEs reported in patients treated with celecoxib compared with diclofenac. These data may help physicians in their treatment decisions for elderly patients with arthritis.

Using clinical trial data and linked administrative health data to reduce the risk of adverse events associated with the uptake of newly released drugs by older Australians: a model process

Background

The study was undertaken to evaluate the contribution of a process which uses clinical trial data plus linked de-identified administrative health data to forecast potential risk of adverse events associated with the use of newly released drugs by older Australian patients.

Methods

The study uses publicly available data from the clinical trials of a newly released drug to ascertain which patient age groups, gender, comorbidities and co-medications were excluded in the trials. It then uses linked de-identified hospital morbidity and medications dispensing data to investigate the comorbidities and co-medications of patients who suffer from the target morbidity of the new drug and who are the likely target population for the drug. The clinical trial information and the linked morbidity and medication data are compared to assess which patient groups could potentially be at risk of an adverse event associated with use of the new drug.

Results

Applying the model in a retrospective real-world scenario identified that the majority of the sample group of Australian patients aged 65 years and over with the target morbidity of the newly released COX-2-selective NSAID rofecoxib also suffered from a major morbidity excluded in the trials of that drug, indicating a substantial potential risk of adverse events amongst those patients. This risk was borne out in post-release morbidity and mortality associated with use of that drug.

Conclusions

Clinical trial data and linked administrative health data can together support a prospective assessment of patient groups who could be at risk of an adverse event if they are prescribed a newly released drug in the context of their age, gender, comorbidities and/or co-medications. Communication of this independent risk information to prescribers has the potential to reduce adverse events in the period after the release of the new drug, which is when the risk is greatest.

Note: The terms 'adverse drug reaction' and 'adverse drug event' have come to be used interchangeably in the current literature. For consistency, the authors have chosen to use the wider term 'adverse drug event' (ADE).

Polarizable empirical force field for sulfur-containing compounds based on the classical Drude oscillator model

Condensed-phase computational studies of molecules using molecular mechanics approaches require the use of force fields to describe the energetics of the systems as a function of structure. The advantage of polarizable force fields over nonpolarizable (or additive) models lies in their ability to vary their electronic distribution as a function of the environment. Toward development of a polarizable force field for biological molecules, parameters for a series of sulfur-containing molecules are presented. Parameter optimization was performed to reproduce quantum mechanical and experimental data for gas phase properties including geometries, conformational energies, vibrational spectra, and dipole moments as well as for condensed phase properties such as heats of vaporization, molecular volumes, and free energies of hydration. Compounds in the training set include methanethiol, ethanethiol, propanethiol, ethyl methyl sulfide, and dimethyl disulfide. The molecular volumes and heats of vaporization are in good accordance with experimental values, with the polarizable model performing better than the CHARMM22 nonpolarizable force field. Improvements with the polarizable model were also obtained for molecular dipole moments and in the treatment of intermolecular interactions as a function of orientation, in part due to the presence of lone pairs and anisotropic atomic polarizability on the sulfur atoms. Significant advantage of the polarizable model was reflected in calculation of the dielectric constants, a property that CHARMM22 systematically underestimates. The ability of this polarizable model to accurately describe a range of gas and condensed phase properties paves the way for more accurate simulation studies of sulfur-containing molecules including cysteine and methionine residues in proteins.

Do COX-2 inhibitors raise blood pressure more than nonselective NSAIDs and placebo? An updated meta-analysis

BACKGROUND

Both COX-2 selective inhibitors (coxibs) and nonselective (ns)-NSAIDs elevate blood pressure (BP) and this may contribute to excess cardiovascular (CV) events. A number of recent large-scale randomized clinical trials (RCTs) comparing coxibs (including newer agents, lumiracoxib and etoricoxib) to both ns-NSAIDs and placebo have been reported, permitting an update to earlier BP analyses of these agents.

DATA SOURCES/SYNTHESIS

Our search yielded 51 RCTs involving coxibs published before April 2008 with a total of 130 541 participants in which BP data were available. The Der Simonian and Laird random effects method for dichotomous variables was used to produce risk ratios (RR) for development of hypertension.

RESULTS

For coxibs versus placebo, there was a RR of 1.49 (1.18-1.88, P = 0.04) in the development of new hypertension. For coxibs versus ns-NSAIDs, the RR was 1.12 (0.93-1.35, P = 0.23). These results were mainly driven by rofecoxib, with a RR of 1.87 (1.63-2.14, P = 0.08) versus placebo, and etoricoxib, with a RR of 1.52 (1.39-1.66, P = 0.01) versus ns-NSAID.

CONCLUSION

On the basis of this updated meta-analysis, coxibs appear to produce greater hypertension than either ns-NSAIDs or placebo. However, this response was heterogeneous, with markedly raised BP associated with rofecoxib and etoricoxib, whereas celecoxib, valdecoxib and lumiracoxib appeared to have little BP effect. The relationship of this increased risk of hypertension to subsequent adverse CV outcomes requires further investigation and prospective RCTs.

Pooled analysis of rofecoxib placebo-controlled clinical trial data: lessons for postmarket pharmaceutical safety surveillance

BACKGROUND

In September 2004, rofecoxib was voluntarily withdrawn from the worldwide market. Our objective was to determine whether and when analysis of published and unpublished placebo-controlled trials could have revealed cardiovascular risk associated with rofecoxib before its withdrawal as an example to inform future postmarket pharmaceutical safety surveillance efforts.

METHODS

We conducted a cumulative subject-level pooled analysis of data from all randomized, placebo-controlled trials of rofecoxib conducted by the manufacturer before September 2004. Our main outcome measurement was incidence of any investigator-reported death from any cause or cardiovascular thromboembolic (CVT) adverse event.

RESULTS

We identified 30 randomized, placebo-controlled trials of rofecoxib that enrolled a combined 20 152 subjects. Trial duration ranged from 4 weeks to 4 years; enrollment ranged from 17 to 2586 subjects prescribed either rofecoxib or placebo; and rofecoxib dose ranged from 12.5 mg to 50 mg. As of December 2000, 21 of these trials had been completed (70%), and the risk of a CVT adverse event or death was greater among subjects assigned to the rofecoxib group (rate ratio [RR], 2.18; 95% confidence interval [CI], 0.93-5.81) (P = .07), raising concerns from a safety standpoint. Subsequently collected data through June 2001 showed that rofecoxib was associated with a 35% increased risk of a CVT adverse event or death (RR, 1.35; 95% CI, 1.00-1.96) (P = .05). Analyzing data available as of April 2002, we found a 39% increased risk (RR, 1.39; 95% CI, 1.07-1.80) (P = .02), and using data available as of September 2004, we found a 43% increased risk (RR,1.43; 95% CI, 1.16-1.76) (P < .001).

CONCLUSION

Cumulative pooled analysis of all randomized, placebo-controlled trials demonstrates a trend toward increased cardiovascular risk associated with rofecoxib compared with placebo as early as December 2000, the comparison reaching a P value of .05 by June 2001, nearly 3(1/2) years before the manufacturer's voluntary market withdrawal.

Prevention of NSAID-related upper gastrointestinal toxicity: a meta-analysis of traditional NSAIDs with gastroprotection and COX-2 inhibitors

Background:

Traditional NSAIDs (tNSAIDs) and COX-2 inhibitors (COX-2s) are important agents for the treatment of a variety or arthritic conditions. The purpose of this study was to systematically review the effectiveness of misoprostol, H2-receptor antagonists (H2RAs), and proton pump inhibitors (PPIs) for the prevention of tNSAID related upper gastrointestinal (GI) toxicity, and to review the upper gastrointestinal (GI) safety of COX-2s.

Methods:

An extensive literature search was performed to identify randomized controlled trials (RCTs) of prophylactic agents used for the prevention of upper GI toxicity, and RCTs that assessed the GI safety of the newer COX-2s. Meta-analysis was performed in accordance with accepted techniques.

Results:

39 gastroprotection and 69 COX-2 RCTs met inclusion criteria. Misoprostol, PPIs, and double doses of H2RAs are effective at reducing the risk of both endoscopic gastric and duodenal tNSAID-induced ulcers. Standard doses of H2RAs are not effective at reducing the risk of tNSAID-induced gastric ulcers, but reduce the risk of duodenal ulcers. Misoprostol is associated with greater adverse effects than the other agents, particularly at higher doses. COX-2s are associated with fewer endoscopic ulcers and clinically important ulcer complications, and have fewer treatment withdrawals due to GI symptoms than tNSAIDS. Acetylsalicylic acid appears to diminish the benefit of COX-2s over tNSAIDs. In high risk GI patients, tNSAID with a PPI or a COX-2 alone appear to offer similar GI safety, but a strategy of a COX-2 with a PPI appears to offer the greatest GI safety.

Conclusion:

Several strategies are available to reduce the risk of upper GI toxicity with tNSAIDs. The choice between these strategies needs to consider patients’ underlying GI and cardiovascular risk.

The safety of celecoxib in ankylosing spondylitis treatment

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) play a crucial role in the treatment of ankylosing spondylitis (AS). Most of the AS patients require a continuous and long-term NSAIDs therapy; therefore the question of NSAIDs safety in this population becomes very important.

OBJECTIVE

to review the safety of celecoxib in ankylosing spondylitis treatment.

METHODS

The PubMed database was searched using the keywords 'ankylosing spondylitis' and 'celecoxib', with the following extraction of clinical trials investigating efficacy and safety of celecoxib in AS.

RESULTS/CONCLUSIONS

Four clinical trials were found: three randomized controlled trials (RCTs) and one open-label extension of a previous RCT. All RCTs showed a good safety profile for celecoxib treatment in AS, similar to that of nonselective NSAIDs. However, long-term (>or= 1 year) celecoxib safety in AS was not investigated in RCTs. Based on the results of long-term non-AS celecoxib studies, most of the AS patients (because of young age and fewer comorbidities) are probably at low risk for cardiovascular and gastrointestinal complications. Celecoxib showed a good efficacy and safety profile in AS, but further investigations are needed to clarify the long-term safety of celecoxib in this group of patients.

COX-2 selective inhibitors in the treatment of osteoarthritis

OBJECTIVES

To assess the efficacy of cyclooxygenase-2 selective inhibitors (coxibs) in osteoarthritis (OA) and their gastrointestinal, cardiovascular, renovascular, and hepatic side effects compared with traditional nonsteroidal antiinflammatory drugs (NSAIDs) and acetaminophen.

METHODS

Bibliographic database searches for randomized controlled trials, meta-analyses, and literature reviews.

RESULTS

Coxibs are comparable to traditional NSAIDs, providing moderate benefit for OA patients in pain and function versus placebo. NSAIDs, including coxibs, are superior to acetaminophen for OA, particularly in patients with moderate to severe pain. Coxibs decrease gastroduodenal ulcers (74% relative risk reduction) and ulcer complications (61% reduction) versus traditional NSAIDs. Meta-analysis of randomized trials indicates that coxibs increase the risk of myocardial infarctions approximately twofold versus placebo and versus naproxen, but do not increase the risk versus nonnaproxen NSAIDs. NSAIDs, including coxibs, commonly cause fluid retention and increase blood pressure and uncommonly induce congestive heart failure or significant renal dysfunction; risk factors include advanced age, hypertension, and heart or kidney disease. NSAIDs are a rare cause of clinical hepatotoxicity (<1 liver-related death per 100,000 NSAID users in clinical studies). Increased rates of aminotransferase elevations occur with rofecoxib (2%) and high-dose lumiracoxib (3%), and postmarketing cases of clinical liver injury with lumiracoxib have been reported recently.

CONCLUSIONS

Coxibs are as effective as traditional NSAIDs and superior to acetaminophen for the treatment of OA. Coxibs cause fewer gastrointestinal complications than traditional NSAIDs. Coxibs increase cardiovascular risk versus placebo and naproxen-but probably not versus nonnaproxen NSAIDs. Blood pressure commonly increases after initiation of selective or nonselective NSAIDs, especially in hypertensive patients.

Non-steroidal anti-inflammatory drugs and myocardial infarctions: comparative systematic review of evidence from observational studies and randomised controlled trials

OBJECTIVE

The comparative risk of myocardial infarction (MI) with cyclo-oxygenase-2-specific drugs and traditional non-steroidal anti-inflammatory drugs (NSAIDs) was determined.

METHODS

The results of studies of a suitable size in colonic adenoma and arthritis-that had been published in English and from which crude data about MIs could be extracted-were evaluated. Medline, Embase and Cinahl (2000-2006) databases, as well as published bibliographies, were used as data sources. Systematic reviews examined MI risks in case-control and cohort studies, as well as in randomised controlled trials (RCTs).

RESULTS

14 case-control studies (74 673 MI patients, 368 968 controls) showed no significant association of NSAIDs with MI in a random-effects model (OR 1.17; 95% CI 0.99 to 1.37) and a small risk of MI in a fixed-effects model (OR 1.32; 95% CI 1.29 to 1.35). Sensitivity analyses showed higher risks of MI in large European studies involving matched controls. Six cohort studies (387 983 patient years, 1 120 812 control years) showed no significant risk of MI with NSAIDs (RR 1.03; 95% CI 1.00 to 1.07); the risk was higher with rofecoxib (RR 1.25; 95% CI 1.17 to 1.34) but not with any other NSAIDs. Four RCTs of NSAIDs in colonic adenoma (6000 patients) showed an increased risk of MI (RR 2.68; 95% CI 1.43 to 5.01). Fourteen RCTs in arthritis (45 425 patients) showed more MIs with cyclo-oxygenase-2-specific drugs (Peto OR 1.6; 95% CI 1.1 to 2.4), but fewer serious upper gastrointestinal events (Peto OR 0.40; 95% CI 0.31 to 0.53).

CONCLUSION

The overall risk of MI with NSAIDs and cyclo-oxygenase-2-specific drugs was small; rofecoxib showed the highest risk. There was an increased MI risk with cyclo-oxygenase-2-specific drugs compared with NSAIDs, but less serious upper gastrointestinal toxicity.

Gastrointestinal safety of cyclooxygenase-2 inhibitors: a Cochrane Collaboration systematic review

BACKGROUND & AIMS

Nonselective non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase-2 inhibitors (COX-2s) are used to treat a variety of arthritic and inflammatory conditions. The aim of this study was to assess the upper gastrointestinal (GI) harms of the long-term use of COX-2s, compared with nonselective NSAIDs and placebo, in arthritis sufferers.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted. Searches were conducted in (1) Cochrane Central Register of Controlled Trials (CENTRAL), (2) the Cochrane Collaboration Library (2005), (3) MEDLINE (to December 2006), and (4) Excerpta Medica Database (EMBASE) (to June 2005). Reference lists from trials and abstracts of conference proceedings were searched by hand, and experts were contacted to identify further relevant trials. RCTs of celecoxib, rofecoxib, etoricoxib, valdecoxib, and lumiracoxib were included if they reported on endoscopic ulcers, clinically important ulcer complications, or adverse gastrointestinal (GI) symptoms with the use of these COX-2s, compared with placebo or with nonselective NSAIDs. Study selection and data extraction were performed in duplicate by independent reviewers. Data were analyzed by using Review Manager 4.2 in accordance with accepted meta-analysis techniques.

RESULTS

Compared with nonselective NSAIDs, COX-2s produced significantly fewer gastroduodenal ulcers (relative risk, 0.26; 95% confidence interval, 0.23-0.30) and clinically important ulcer complications (relative risk, 0.39; 95% confidence interval, 0.31-0.50), as well as fewer treatment withdrawals caused by GI symptoms. The co-administration of acetylsalicylic acid appears to reduce the GI safety of COX-2s in subgroup analyses.

CONCLUSIONS

COX-2s appear to offer greater upper GI safety and are better tolerated than nonselective NSAIDs. The co-administration of acetylsalicylic acid might reduce the safety advantage of COX-2s over that of nonselective NSAIDs.

Open-Label Extension Studies

The number of open-label extension studies being performed has increased enormously in recent years. Often it is difficult to differentiate between these extension studies and the double-blind, controlled studies that preceded them. If undertaken primarily to gather more patient-years of exposure to the new drug in order to understand and gain confidence in its safety profile, open-label extension studies can play a useful and legitimate role in drug development and therapeutics. However, this can only occur if the open-label extension study is designed, executed, analysed and reported competently. Most of the value accrued in open-label extension studies is gained from a refinement in the perception of the expected incidence of adverse effects that have most likely already been identified as part of the preclinical and clinical trial programme. We still have to rely heavily on post-marketing safety surveillance systems to alert us to type B (unpredictable) adverse reactions because open-label extension studies are unlikely to provide useful information about these types of often serious and relatively rare adverse reactions. Random allocation into test and control groups is needed to produce precise incidence data on pharmacologically expected, or type A, adverse effects. Some increased confidence about incidence rates might result from the open-label extension study; however, as these studies are essentially uncontrolled and biased, the data are not of great value. Other benefits have been proposed to be gained from open-label extension studies. These include ongoing access to an effective but otherwise unobtainable medicine by the volunteers who participated in the phase III pivotal trials. However, there are unappreciated ethical issues about the appropriateness of enrolling patients whose response to previous treatment is uncertain, largely because treatment allocation in the preceding randomised, double-blind, controlled trial has not been revealed at the time of entry into the open-label extension study. Negative aspects of open-label extension studies revolve around their use as a marketing tool, as they build a market for the drug and generate pressure for subsidised access to the drug from consumers and their physicians. Consumers, institutions where these studies are conducted and research ethics committees need to be convinced of the motives, as well as the quality, of the open-label extension study and its execution before supporting such studies. Open-label extension studies do have a legitimate but limited place in the clinical development of new medicines. The negative perceptions about these studies have arisen because of perversion of acceptable rationales for this type of study and a failure to recognise (or disclose) the limitations resulting from the inherent weaknesses in their design. Increased human exposure to a new medicine under reasonably controlled circumstances to increase confidence in the safety of the medicine is an acceptable rationale for an open-label extension study, and a useful activity to increase the knowledge of the safety profile of a new medicine. However, this goal is increasingly being achieved by means other than open-label extension studies.

Expectations from patients with rheumatoid arthritis regarding COX-2s: cutting to the heart of the matter

Before the withdrawal of 2 COX-2 selective agents (COX-2s) from the market, many rheumatoid arthritis patients were using these products regularly, with disease-modifying antirheumatic agents. Clinical trials have shown benefit of COX-2s equivalent to nonselective nonsteroidal anti-inflammatory drugs (NS-NSAIDs) in rheumatoid arthritis. Better gastrointestinal (GI) safety has been demonstrated with COX-2s; numerical but not statistical benefit with concomitant use of cardiovascular (CV) doses of aspirin. COX-2 benefit may extend to lower GI blood loss against which proton pump inhibitors are not protective. COX-2s are associated with hypertension and edema of similar magnitude to NS-NSAIDs in predisposed individuals. Epidemiologic studies and clinical trials have confirmed the association of serious thromboembolic (CV) events and congestive heart failure with rofecoxib>25 mg daily, celecoxib, and NS-NSAIDs, although there is a paucity of long-term data. Important questions remain regarding relative GI and CV risks: is concomitant aspirin protective when coadministered with COX-2s? Does this abrogate their GI benefit? As identified many years ago with NS-NSAIDs, patients may respond to one and not another; COX-2s should be considered individually and not as a single "class." Patients deserve the opportunity to make a choice about the perceived benefit/risk assessment when using these therapies, with the collaboration of their physician.

Update on guidelines for the treatment of chronic musculoskeletal pain

Chronic musculoskeletal pain is a major - and growing - burden on today's ageing populations. Professional organisations including the American College of Rheumatology (ACR), American Pain Society (APS) and European League Against Rheumatism (EULAR) have published treatment guidelines within the past 5 years to assist clinicians achieve effective pain management. Safety is a core concern in all these guidelines, especially for chronic conditions such as osteoarthritis that require long-term treatment. Hence, there is a consensus among recommendations that paracetamol should be the first-line analgesic agent due to its favourable side effect and safety profile, despite being somewhat less effective in pain relief than anti-inflammatory drugs. Cyclooxygenase-2 (COX-2)-selective anti-inflammatory drugs were developed with the goal of delivering effective pain relief without the serious gastrointestinal (GI) side effects linked with traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs). Clinical trial evidence supported these benefits, and COX-2 inhibitors were widely adopted, both in clinical practice and in official guidelines. Recently, accumulating data have linked COX-2 inhibitors with serious cardiovascular and/or cardiorenal effects and/or serious cutaneous adverse reactions (SCARs), particularly at anti-inflammatory doses or when used long term. Regulatory authorities in both Europe and the USA have responded to these data with the withdrawal of rofecoxib and valdecoxib, and the strengthening of prescribing advice on all anti-inflammatory drugs. COX-2 inhibitors and non-selective NSAIDs should now be used with increased caution in patients at increased cardiovascular and/or cardiorenal risk, e.g., patients with congestive heart failure, hypertension, etc. Regulatory advice and good clinical practice are to use anti-inflammatory drugs at the lowest effective dose and for the shortest possible time. There are as yet no updated official guidelines that incorporate these new data and regulatory advice. An international multidisciplinary panel, the Working Group on Pain Management, has generated new recommendations for the treatment of moderate-to-severe musculoskeletal pain. These guidelines, formulated in response to recent developments concerning COX-2 inhibitors and other NSAIDs, focus on paracetamol as the baseline drug for chronic pain management; when greater analgesia is desired, the addition of weak opioids is recommended based on a preferable GI and cardiovascular profile, compared with non-steroidal anti-inflammatory drugs.

Cardiovascular risk with cyclooxygenase inhibitors: general problem with substance specific differences?

Randomised clinical trials and observational studies have shown an increased risk of myocardial infarction, stroke, hypertension and heart failure during treatment with cyclooxygenase inhibitors. Adverse cardiovascular effects occurred mainly, but not exclusively, in patients with concomitant risk factors. Cyclooxygenase inhibitors cause complex changes in renal, vascular and cardiac prostanoid profiles thereby increasing vascular resistance and fluid retention. The incidence of cardiovascular adverse events tends to increase with the daily dose and total exposure time. A comparison of individual selective and unselective cyclooxygenase inhibitors suggests substance-specific differences, which may depend on differences in pharmacokinetic parameters or inhibitory potency and may be contributed by prostaglandin-independent effects. Diagnostic markers such as N-terminal pro brain natriuretic peptide (NT-proBNP) or high-sensitive C-reactive protein might help in the early identification of patients at risk, thus avoiding the occurrence of serious cardiovascular toxicity.

Prescriptions for chronic high-dose cyclooxygenase-2 inhibitors are often inappropriate and potentially dangerous

OBJECTIVE

To describe the use of coxibs outside of licensed indications and recommended dosing ranges including rofecoxib 50 mg, valdecoxib 20 to 40 mg, and celecoxib 400 mg.

DESIGN

Cross-sectional study of coxib utilization in 2002 and 2003 and retrospective cohort analysis of new users.

PARTICIPANTS

Patients with known age and sex enrolled in Tennessee's Medicaid program.

MEASUREMENTS

The prevalence of coxib use by dose and duration, and the proportion of persons initially prescribed a high-dose coxib and indications for such use.

RESULTS

The estimated daily prevalence of nonaspirin prescription nonsteroidal anti-inflammatory drugs (NSAIDs) was 8.7% in 2002 to 2003 (45.7% coxibs). NSAID use peaked at age 65 to 74 with a prevalence of 19.8% (56.3% coxibs). Doses above the recommended daily dose for osteoarthritis accounted for 33.2% (95% confidence intervals [CIs] 32.4%, 33.9%) of celecoxib use, 14.9% (95% CI 14.4%, 15.5%) of rofecoxib use, and 52.2% (95% CI 50.6%, 53.8%) of valdecoxib use. Most of these prescriptions were for a month's supply. For new coxib users, 13.5% were given a month's supply for the highest dose category, and 28% refilled their prescriptions within 7 days of the end of the original prescription. Of these new chronic high-dose users, 17.2% had ischemic heart disease and 7.1% had heart failure.

CONCLUSIONS

A substantial portion of coxib prescriptions were for a month's supply at doses above those recommended for most chronic indications. New users were also prescribed high doses despite evidence for cardiovascular comorbidity. These prescribing patterns at doses outside licensed indications are both inappropriate and potentially dangerous.

Rofecoxib for rheumatoid arthritis

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. Rheumatoid arthritis (RA) is a systemic auto-immune disorder, in which the synovial lining of many joints and tendon sheaths are persistently inflamed.

OBJECTIVES

To assess the efficacy and toxicity of rofecoxib for treating RA.

SEARCH STRATEGY

We searched the following electronic databases up to December 2000: 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 were scanned for additional references. The manufacturers of rofecoxib, MSD, were also approached by the UK National Institute for Clinical Excellence to submit additional evidence to inform it's appraisal on the use of cyclo-oxygenase inhibitors for arthritis.

SELECTION CRITERIA

We included randomised controlled trials of parallel group design evaluating the efficacy and/or toxicity of rofecoxib in RA, both placebo based and comparative trials were eligible. Relevant outcome criteria had to be available to evaluate efficacy and/or toxicity, such as the OMERACT outcomes.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by two reviewers and the results were compared for the degree of agreement. A validated tool (Jadad 1996) was used to score the quality of the randomised controlled trials. The planned analysis was to pool, where appropriate, continuous outcome measures using mean or standardized mean differences, and dichotomous outcome measures using relative risk ratios.

MAIN RESULTS

Two randomised controlled trials evaluating rofecoxib for the treatment of RA were identified and met the inclusion criteria. One compared rofecoxib to placebo and was designed to assess the safety and efficacy of several doses of rofecoxib. The second trial compared rofecoxib to naproxen and was primarily designed to assess the safety of rofecoxib so did not include all the recommended RA efficacy measures. The overall number of ACR 20 responders who had received 25mg (82/ 171 = 48%) or 50mg (86/161 = 53%) was statistically significantly more than those receiving placebo (58/168 = 35% ) (RR 1.39 CI: 1.07, 1.80 and RR 1.55 CI: 1.20, 1.99 respectively) with no statistically significant differences between the 25 and 50 mg doses. The safety profile of rofecoxib was similar to that of placebo. In the comparative trial, rofecoxib at a dosage of 50 mg/day demonstrated similar efficacy to naproxen at a dosage of 500 mg twice daily. However, the combined rate of clinically significant complicated gastro-intestinal events (GI) (perforations, ulcers, bleeds, or obstructions) was lower with rofecoxib than with naproxen (RR 0.46, 95% CI, 0.34 to 0.63) due to a reduction in the number of ulcers and bleeds. Compared to patients taking naproxen, patients taking rofecoxib had a greater risk of having any cardiovascular event (45/4047 = 1.1% vs 19/4029 =0.47%) (RR 2.36 CI 1.38 to 4.02) and had greater risk of having a non-fatal myocardial infarction (MI) (18/4047 =0 .44% and 4/4029 =0.1%) (RR 4.48, 95% CI, 1.52 to 13.23).

AUTHORS' CONCLUSIONS

In patients with RA, rofecoxib demonstrates a greater degree of efficacy than placebo, while having a comparable safety profile. Rofecoxib demonstrates a similar degree of efficacy as naproxen, but with a significantly lower rate of ulceration and gastrointestinal bleeding. Rofecoxib was associated with a greater risk for MI, but the exact significance and pathophysiology of this possible relationship is unclear. Rofecoxib was voluntarily withdrawn from global markets in October 2004. It cannot therefore be prescribed and therefore there are no implications for practice concerning its use. None the less when considering which NSAID to use, it must be borne in mind that the toxicity of NSAIDs is variable amongst patients and drugs and it tends to be dose related and associated with variation in the mode of action, absorption, distribution and metabolism. There remains a number of questions over both the benefits and risks associated with Cox II selective agents and further work is ongoing. It is likely that this issue will not be resolved until research has enabled a fuller understanding of the complex mechanism by which the Cox system operates.

Risk of cardiovascular events and rofecoxib: cumulative meta-analysis

BACKGROUND

The cyclo-oxygenase 2 inhibitor rofecoxib was recently withdrawn because of cardiovascular adverse effects. An increased risk of myocardial infarction had been observed in 2000 in the Vioxx Gastrointestinal Outcomes Research study (VIGOR), but was attributed to cardioprotection of naproxen rather than a cardiotoxic effect of rofecoxib. We used standard and cumulative random-effects meta-analyses of randomised controlled trials and observational studies to establish whether robust evidence on the adverse effects of rofecoxib was available before September, 2004.

METHODS

We searched bibliographic databases and relevant files of the US Food and Drug Administration. We included all randomised controlled trials in patients with chronic musculoskeletal disorders that compared rofecoxib with other non-steroidal anti-inflammatory drugs (NSAIDs) or placebo, and cohort and case-control studies of cardiovascular risk and naproxen. Myocardial infarction was the primary endpoint.

FINDINGS

We identified 18 randomised controlled trials and 11 observational studies. By the end of 2000 (52 myocardial infarctions, 20742 patients) the relative risk from randomised controlled trials was 2.30 (95% CI 1.22-4.33, p=0.010), and 1 year later (64 events, 21432 patients) it was 2.24 (1.24-4.02, p=0.007). There was little evidence that the relative risk differed depending on the control group (placebo, non-naproxen NSAID, or naproxen; p=0.41) or trial duration (p=0.82). In observational studies, the cardioprotective effect of naproxen was small (combined estimate 0.86 [95% CI 0.75-0.99]) and could not have explained the findings of the VIGOR trial.

INTERPRETATION

Our findings indicate that rofecoxib should have been withdrawn several years earlier. The reasons why manufacturer and drug licensing authorities did not continuously monitor and summarise the accumulating evidence need to be clarified.

The upper gastrointestinal safety of rofecoxib vs. NSAIDs: an updated combined analysis

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are nonspecific cyclo-oxygenase (COX-1/COX-2) inhibitors and are associated with gastrointestinal (GI) toxicity attributable to COX-1 inhibition. Rofecoxib, a COX-2 specific inhibitor, was developed to provide similar efficacy and less GI toxicity than NSAIDs.

OBJECTIVE

To update the results of a previously performed analysis of the incidence of upper GI perforations, symptomatic gastroduodenal ulcers, and upper GI bleeding (PUBs) with rofecoxib compared with non-selective NSAIDs.

RESEARCH DESIGN AND METHODS

We compared the incidence of PUBs in a combined analysis of 20 randomized, double-blind, clinical trials of rofecoxib versus NSAIDs. Men and women (N = 17,072) from multinational trial sites with osteoarthritis or rheumatoid arthritis were studied. There was no upper age limit in any of the trials. Investigator-reported PUBs were reviewed by a blinded, external adjudication committee using pre-specified criteria. The incidence of confirmed PUBs, the main outcome measure, among patients treated with rofecoxib 12.5 mg, 25 mg, or 50 mg (combined, N = 10 026) was compared to that among patients treated with ibuprofen, diclofenac, nabumetone, or naproxen (combined, N = 7046).

RESULTS

The incidence of PUBs over 24.8 months was significantly lower with rofecoxib vs. NSAIDs (cumulative incidence 1.6% vs. 3.1%, p < 0.001; rate/100 patient-years 0.74 vs. 1.87; relative risk 0.36, 95% CI 0.24, 0.54). Results of subgroup analyses and comparisons of rofecoxib with individual NSAID comparators were consistent with the primary result, as was an analysis in patients with no PUB risk factors.

DISCUSSION

The analysis demonstrated a consistently lower incidence of confirmed PUBs with rofecoxib than with NSAIDs over 24.8 months. These results confirm those of a previous smaller combined analysis of clinical trials with rofecoxib vs. non-selective NSAIDs in OA patients only, in which the risk reduction for confirmed PUBs was approximately 50%. In addition, this analysis demonstrated risk reductions with rofecoxib vs. NSAIDs in risk subgroups and in patients who did not have any known risk factors for PUBs consistent with the primary result. Some of the studies in this analysis required scheduled endoscopies. Asymptomatic upper GI ulcers or bleeding diagnosed during scheduled procedures were not included in the primary endpoint, which may have caused a bias against rofecoxib.

CONCLUSIONS

Treatment with rofecoxib was associated with a statistically significantly (p < 0.001) lower incidence of PUBs than was treatment with NSAIDs. The difference was maintained in subgroups of patients with risk factors, as well as in those with no risk factors, for PUBs.

Cyclooxygenase isozymes: the biology of prostaglandin synthesis and inhibition

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most highly utilized classes of pharmaceutical agents in medicine. All NSAIDs act through inhibiting prostaglandin synthesis, a catalytic activity possessed by two distinct cyclooxygenase (COX) isozymes encoded by separate genes. The discovery of COX-2 launched a new era in NSAID pharmacology, resulting in the synthesis, marketing, and widespread use of COX-2 selective drugs. These pharmaceutical agents have quickly become established as important therapeutic medications with potentially fewer side effects than traditional NSAIDs. Additionally, characterization of the two COX isozymes is allowing the discrimination of the roles each play in physiological processes such as homeostatic maintenance of the gastrointestinal tract, renal function, blood clotting, embryonic implantation, parturition, pain, and fever. Of particular importance has been the investigation of COX-1 and -2 isozymic functions in cancer, dysregulation of inflammation, and Alzheimer's disease. More recently, additional heterogeneity in COX-related proteins has been described, with the finding of variants of COX-1 and COX-2 enzymes. These variants may function in tissue-specific physiological and pathophysiological processes and may represent important new targets for drug therapy.

Postoperative pain management in obstetric anesthesia–new challenges and solutions

The current understanding of pain processing mechanisms, the different pharmacologic drugs, and other nonpharmacologic means that can be used to manage postobstetric operation pain are reviewed.

Selective COX-2 inhibition and cardiovascular effects: a review of the rofecoxib development program

See related Editorials on pages 561 and 563. Cyclo-oxygenase-2 (COX-2) inhibitors appear to alter the balance of vasoactive eicosanoids (prostacyclin and thromboxane) and to suppress the inflammatory mediators implicated in the progression of atherogenesis and ischemic myocardial injury. Neutral, harmful, and beneficial cardiovascular (CV) effects have all been postulated to result from these changes. Investigations conducted with rofecoxib, a selective COX-2 inhibitor, have substantially contributed to our understanding of this scientific area. Rofecoxib had little or no effect on platelet aggregation or platelet-derived thromboxane synthesis but reduced systemic prostacyclin synthesis by 50% to 60%. These findings prompted extensive analyses of CV thrombotic events within the rofecoxib development program. Among 5435 osteoarthritis trial participants, similar rates of CV thrombotic events were reported with rofecoxib, placebo, and comparator, nonselective NSAIDs (ibuprofen, diclofenac, and nabumetone). In the VIGOR gastrointestinal outcomes trial of >8000 patients, naproxen (an NSAID with aspirin-like sustained antiplatelet effects throughout its dosing interval) was associated with a significantly lower risk of CV events than was rofecoxib. A subsequent pooled analysis from 23 studies (including VIGOR) encompassing multiple disease states and including more than 14,000 patient-years at risk also demonstrated that rofecoxib was not associated with excess CV thrombotic events compared with either placebo or nonnaproxen NSAIDs. Again, naproxen appeared to be the outlier, suggesting a cardioprotective benefit of naproxen. Finally, among the predominantly elderly, male population participating in Alzheimer trials, both rofecoxib- and placebo-treated patients had similar rates of CV thrombotic events. The totality of data is not consistent with an increased CV risk among patients taking rofecoxib.

[Cyclooxygenase 2 selective antirheumatic analgesics]

Because of Cyclooxygenase-2 selective non steroidal anti-inflammatory drugs (NSAIDs), the therapy of articular pain has become safer and more convenient. Currently, two highly Cyclooxygenase-2 selective drugs, celecoxib and rofecoxib, are available. Both are effective for patients with osteoarthritis (at daily dosages of 200 mg and 12.5 mg, respectively) and rheumatoid arthritis (RA) (at twice the above dosages). At higher daily dosages of 800 mg and 50 mg these substances still appear safe with regard to life-threatening gastrointestinal complications (perforation, obstruction, bleeding), if not given with concomitant aspirin. However, Cyclooxygenase-2 selective non steroidal anti-inflammatory drugs do not confer protection against platelet aggregation and aspirin must be given where required for cardiovascular prophylaxis. Most patients will then routinely need gastroprotective agents such as proton pump inhibitors or misoprostol; it is unclear whether coxibs confer any benefit under such circumstances. Although not a coxib, Meloxicam does not appear to cause serious gastrointestinal complications if the low daily dosage of 7.5 mg is sufficient for the control of less pronounced pain and thus not exceeded. The gastrointestinal safety of nimesulide can not be sufficiently evaluated based on the available clinical data.

Current drug therapy for rheumatoid arthritis

The etiology of rheumatoid arthritis (RA) remains unclear at present, but advances have been made in the drug therapy for RA. Recent attention has been focused on selective cyclooxygenase-2 (COX-2) inhibitors, nonsteroidal antiinflammatory drugs (NSAIDs) that inhibit a subtype of cyclooxygenase. Various clinical studies have confirmed that the selective COX-2 inhibitors cause fewer severe gastrointestinal complications, although an increased incidence of myocardial infarction was suggested. Terminal enzymes of the arachidonic acid cascade, such as membrane-associated prostaglandin E synthase, might be a target for new NSAIDs in the near future. Low-dose glucocorticoid treatment for RA has been reconsidered possibly to prevent articular destruction of RA. Special attention for glucocorticoid-induced osteoporosis by concomitant administration of bisphosphonates might be necessary. Disease-modifying antirheumatic drugs should be effective in delaying the progression of joint destruction and physical disability. Methotrexate, sulfasalazine, and leflunomide have shown such an effect. Inhibition of articular destruction was also proven by administration of the biologic agents etanercept and infliximab plus methotrexate. Tuberculosis complicated with infliximab therapy is one of the most important concerns in Japan. Agents that improve the quality of life of patients with RA are still needed.

Rofecoxib: an update on physicochemical, pharmaceutical, pharmacodynamic and pharmacokinetic aspects

Rofecoxib (MK-966) is a new generation non-steroidal anti-inflammatory agent (NSAID) that exhibits promising anti-inflammatory, analgesic and antipyretic activity. It selectively inhibits cyclooxygenase (COX)-2 isoenzyme in a dose-dependent manner in man. No significant inhibition of COX-1 is observed with rofecoxib up to doses of 1000 mg. The pharmacokinetics of rofecoxib has been found to be complex and variable. Mean oral bioavailability after single dose of rofecoxib (12.5, 25 or 50 mg) is 93% with t(max) varying widely between 2 and 9 h. It is highly plasma-protein bound and is metabolized primarily by cytosolic reductases to inactive metabolites. Rofecoxib is eliminated predominantly by hepatic metabolism with a terminal half-life of approximately 17 h during steady state. Various experimental models and clinical studies have demonstrated rofecoxib to be superior, or at least equivalent, in anti-inflammatory, analgesic and antipyretic efficacy to comparator nonselective NSAIDs in osteoarthritis, rheumatoid arthritis and other pain models. Emerging evidence suggests that rofecoxib may also find potential use as supportive therapy in various pathophysiologic conditions like Alzheimer's disease, and in various malignant tumours and polyps, where COX-2 is overly expressed. Rofecoxib is generally well-tolerated. Analysis of data pooled from several trials suggests that rofecoxib is associated with fewer incidences of clinically symptomatic gastrointestinal ulcers and ulcer complications vis-à-vis conventional NSAIDs. However, this gastropreserving effect may be negated by concurrent use of low-dose aspirin for cardiovascular risk reduction. Rofecoxib tends to show similar tolerability for renal and cardiothrombotic events as compared with nonnaproxen nonselective NSAIDs. No clinically significant drug interaction has been reported for rofecoxib except with diuretics, where it reverses their salt-wasting effect and thus can be clinically exploited in electrolyte-wasting disorders. There is only modest information about the physicochemical and pharmaceutical aspects of rofecoxib. Being poorly water soluble, its drug delivery has been improved using varied formulation approaches. Although it is stable in solid state, rofecoxib is photosensitive and base-sensitive in solution form with its degradation mechanistics elucidated. Analytical determinations of rofecoxib and its metabolites in biological fluids employing HPLC with varied types of detectors have been reported. Isolated studies have also been published on the chromatographic and spectrophotometric assay of rofecoxib and its degradants in bulk samples and pharmaceutical dosage forms. The current article provides an updated overview on the physicochemical, pharmaceutical, pharmacokinetic and pharmacodynamic vistas of rofecoxib.

Effects of renal insufficiency and hemodialysis on the pharmacokinetics of rofecoxib

Rofecoxib (VIOXX, Merck & Co., West Point, PA) is a COX-2-selective inhibitor that combines anti-inflammatory and analgesic efficacy with improved gastrointestinal (GI) safety. The present open-label study investigated the pharmacokinetics, safety, and tolerability of a single, oral dose of rofecoxib (50 mg) in patients with end-stage renal failure (creatinine clearance <5 mL/min/1.73 m(2)) requiring hemodialysis. Rofecoxib AUC(0-48 h), AUC(0- infinity), C(max), T(max), and t(1/2) obtained from renal failure patients on hemodialysis were not significantly different from those obtained from healthy subjects. With hemodialysis initiated 48 hours postdose, rofecoxib AUC(0-48 h) adjusted mean ratio (renal failure/healthy subjects) was 0.81, with a corresponding 90% confidence interval (CI; 0.66, 1.00). Hemodialysis per se had no clinically meaningful effect on rofecoxib pharmacokinetics: plasma rofecoxib concentration-time curves were virtually superimposable when hemodialysis was initiated at 4 or 48 hours following rofecoxib dosing, although mean rofecoxib C(max) was 18% lower during the former (325 versus 395 ng/mL; P = 0.014). Overall, rofecoxib was well tolerated in end-stage renal disease patients. In this study, end-stage renal disease and hemodialysis had little effect on rofecoxib pharmacokinetics. Although there are no clinical data to support the use of rofecoxib in patients with severe renal insufficiency (creatinine clearance, 5-30 mL/min/1.73 m(2)), these data suggest that dosage adjustment of rofecoxib is not needed for patients with impaired renal function.

Effects of selective COX-2 inhibitors on the gastric permeability of sucrose: a controlled study with placebo and ibuprofen

OBJECTIVE

Acute and chronic use of non-steroidal anti-inflammatory drugs can increase gastrointestinal permeability. Celecoxib, which selectively inhibits the enzyme cyclooxygenase-2, is a novel anti-inflammatory drug with minimal gastrointestinal toxic effects while retaining anti-inflammatory efficacy. Our aim was to assess the potential effects of celecoxib on gastric permeability in comparison with placebo and ibuprofen.

DESIGN

We conducted a prospective, double-blind, cross-over study.

SETTING

This study is carried out at Marmara University Hospital.

PARTICIPANTS

Twenty-five healthy subjects entered the study but 19 subjects completed the treatment.

INTERVENTION

Subjects were randomized to celecoxib 100 mg twice daily, ibuprofen 600 mg twice daily or placebo for 7 days in pre-defined sequences. Treatments were separated by a 7 day washout period.

MAIN OUTCOME MEASURE

Gastric permeability was assessed by measuring urinary excretion of sucrose spectrophotometrically.

RESULTS

Ibuprofen 600 mg twice daily produced greater increases in gastric permeability compared with placebo or celecoxib (geometric mean of urinary sucrose recovery was 59.15, 32.65 and 33.11 mg/h for ibuprofen, placebo and celecoxib, respectively) (P < 0.001). Celecoxib was generally better tolerated than ibuprofen.

CONCLUSIONS

When compared with ibuprofen, celecoxib 100 mg twice daily has no significant effect on gastric mucosa in healthy subjects.

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.

Advances in rheumatology: coxibs and beyond

Arthritis is a growing health concern in the US with approximately 70 million Americans currently affected. This figure will inevitably rise as the population ages. The pain and decreased mobility associated with arthritis have a significant impact on quality of life and because patients with arthritis are less active than the general population, they are at risk of additional conditions such as obesity, heart disease, diabetes, and hypertension. There are currently no disease modifying osteoarthritis (OA) drugs available; therefore anti-inflammatory, and/or analgesic medications such as acetaminophen and NSAIDs and simple analgesics form the mainstay of treatment. Coxibs may be preferred to traditional NSAIDs because of their improved gastrointestinal (GI ) safety and tolerability profile. The use of topical agents may also be beneficial in some patients. In rheumatoid arthritis (RA) where disease modifying drugs (DMARDs) are available, anti-inflammatory agents such as NSAIDs and coxibs are used as adjuncts to disease modifying therapy. However, patients with RA are at increased risk of NSAID-related GI injury, particularly if they are also on corticosteroid medication. Pharmacological treatment of both RA and OA should be combined with appropriate nonpharmacological modalities such as patient education, exercise programs, and joint motion and strengthening exercises. Such activities may delay joint degradation and help maintain physical function.

Improved control of osteoarthritis pain and self-reported health status in non-responders to celecoxib switched to rofecoxib: results of PAVIA, an open-label post-marketing survey in Spain

METHODS

An open-label multicentre study was conducted in primary care centres in Spain to investigate the effect of a switch from celecoxib to rofecoxib among patients with osteoarthritis and to identify factors associated with a good response to rofecoxib treatment. Patients were eligible to participate in this study if their physicians considered that they might benefit from such a change of therapy. A total of 2,228 patients (1481 women) were enrolled in the study: participants' mean age was 66.37 years (SD 9.04). Mean duration of OA was 7.44 (6.38) years. Predominant sites of OA included the knee (1,132 patients, 50.8%), lumbar spine (977 patients, 43.9%) and cervical spine (739 patients, 33.2%). At baseline, most patients (77%) were being prescribed celecoxib 200 mg/day; during the study most (92.5%) received rofecoxib 25 mg/day. The mean interval between switch to rofecoxib and follow-up interview was 33 days.

PRINCIPAL RESULTS

Patients considered the therapeutic response to rofecoxib substantially and significantly superior to that previously obtained with celecoxib for the management of OA-related pain and OA-related health status (p < 0.001). Seventy-two percent of patients classified their response to rofecoxib therapy as 'good' or 'very good' (vs 6.6% of patients at baseline with celecoxib) and 89.3% of patients expressed satisfaction with rofecoxib (vs 28.9% at baseline with celecoxib). Improvements reported in patient self-assessments following rofecoxib therapy were complemented by similar changes in physician perceptions. The number of patients considered by their doctors to have 'good' or 'very good' OA-related health status rose from 10.1% at baseline to 80.0% on completion of rofecoxib therapy. Ancillary indices such as the proportion of patients with self-reported depression were also favourably influenced by the switch to rofecoxib from celecoxib. Determinants of response: Patient characteristics identified in multivariate analysis as predictive of a favourable response to rofecoxib comprised age, obesity, depression, diabetes and OA-related overall health status.

CONCLUSIONS

The results of this observational study indicate that rofecoxib 25 mg/day is likely to be more effective in patients with OA who do not respond well to celecoxib 200 mg/day and satisfies a large proportion of both patients and physicians. These data are of practical interest because they indicate that, at the doses most often used in primary practice in Spain to treat OA, many patients who are dissatisfied with the effects of celecoxib 200 mg/day may benefit from a switch to rofecoxib 25 mg/day. The data obtained in this study also reveal that younger OA patients with relatively uncomplicated clinical circumstances (a population in which use of Coxibs is relatively low at present) are likely to derive substantial benefit from a switch to rofecoxib therapy.

Anti-inflammatory and antiulcerogenic effects of the aqueous extract of Lobaria pulmonaria (L.) Hoffm

An aqeuous extract of Lobaria pulmonaria (L.) Hoffm., from which a tea is prepared and consumed as treatment for various diseases in northeastern Turkey, was tested for its anti-inflammatory and antiulcerogenic effects in rats. The carrageenan-induced paw edema, cotton pellet granuloma and indomethacin-induced gastric damage models were used to determine these effects. The extract exhibited moderate anti-inflammatory and strong antiulcerogenic activities.

A Retrospective Analysis of Cyclooxygenase-II Inhibitor Response Patterns

Objective:

To summarize responses to cyclooxygenase-II (COX-II) medication use and describe physicians' reasons for switching or discontinuing therapy in the management of osteoarthritis.

Methods:

This retrospective medical record review evaluated all patients in a private clinical practice setting with a diagnosis of osteoarthritis who had been prescribed the COX-II inhibitor rofecoxib.

Results:

Of 144 evaluable patients, 81 had previously experienced treatment failure with celecoxib. Sixty-three patients had received rofecoxib as their first COX-II agent. A total of 101 of 144 patients remained on rofecoxib through the time of follow up. Patients starting celecoxib as their first COX-II agent discontinued therapy significantly earlier than those initiating treatment with rofecoxib (p < 0.001). Kaplan–Meier estimates of the median time to discontinuation were 17 weeks for celecoxib and 45 weeks for rofecoxib. There was no significant difference in the time to discontinuation in the first 6 months of therapy with a second COX-II agent between the groups.

Conclusions:

The majority of patients demonstrating therapeutic failure with 1 COX-II inhibitor may successfully be treated with another COX-II agent.

A placebo and active comparator-controlled trial of rofecoxib for the treatment of rheumatoid arthritis

OBJECTIVE

To evaluate the efficacy and tolerability of rofecoxib 25 mg and 50 mg once daily versus placebo and naproxen 500 mg twice daily in patients with RA.

METHODS

Eligible patients were randomized (double-blind) to placebo (n = 289), rofecoxib 25 mg (n = 306), 50 mg (n = 286) once daily, or naproxen (n = 142) for 12 weeks. Efficacy assessments included the ACR core set, with prespecified primary endpoints: patient and investigator global assessments of disease activity, tender and swollen joint counts. Investigator-reported adverse experiences, routine laboratory and vital sign measurements were monitored.

RESULTS

Rofecoxib 25 mg, 50 mg, and naproxen provided similar treatment effects, significantly different from placebo, consistent with improvement, for all primary endpoints. Effects were evident at the earliest assessment (week 2) and sustained for 12 weeks. All treatments were generally well-tolerated.

CONCLUSIONS

Rofecoxib 25 mg once daily had similar efficacy to naproxen 500 mg twice daily (a standard dose). No additional benefit was seen with 50 mg rofecoxib.

Antiangiogenic effect of a highly selective cyclooxygenase-2 inhibitor on gastric ulcer healing in rats

Selective cyclooxygenase-2 (COX-2) inhibitors have been shown to produce fewer gastrointestinal adverse reactions when compared with conventional nonselective nonsteroidal anti-inflammatory drugs and they suppress angiogenesis in tumors. The purpose of the present study was to investigate the effects of highly selective COX-2 inhibitor on angiogenesis and protein expression of angiogenic factor during gastric ulcer healing. Gastric ulcers were induced in male Sprague-Dawley rats by a luminal application of acetic acid solution. Rofecoxib, a selective COX-2 inhibitor, was administered at a dose of 10 mg/kg/day by gastric intubation for 14 successive days. The ulcer size was measured at different time intervals after ulcer induction. The microvessels that were immunohistologically positive for von Willebrand factor within the ulcer bed were counted. The protein levels of basic fibroblast growth factor (bFGF) and concentration of prostaglandin E(2) (PGE(2)) in the ulcer tissues were analyzed with Western blotting and immunoassay methods, respectively. The results demonstrated that rofecoxib treatment significantly increased the ulcer size at days 6, 10, and 15. It decreased the number of microvessels, bFGF protein expression, and PGE(2) level in the ulcer base at day 6. The findings that highly selective COX-2 inhibitor delayed ulcer healing in rats and impaired angiogenesis in the ulcer base raise cautions regarding the use of COX-2 inhibitors in patients with gastric ulcers.

Treatment of rheumatic diseases in children: special considerations

The goals of treatment of rheumatic diseases in children are to control the disease process while ensuring normal nutrition, growth, and development. The choice of antirheumatic drugs is similar in children and adults, but the doses, treatment schedules, and susceptibility to toxicity can differ considerably. In addition to differences between adult and pediatric diseases themselves, it is important for the rheumatologist who treats children to be cognizant of the impact of nutritional, developmental, and growth issues and differential susceptibility to toxicity of various treatments.

The role of rofecoxib, a cyclooxygenase-2-specific inhibitor, for the treatment of non-cancer pain: A review

Rofecoxib was the first specific inhibitor of cyclooxygenase-2 (COX-2) approved for the treatment of acute pain. It has been shown to provide analgesia that is significantly better than placebo and has an onset of action and efficacy similar to that of traditional nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), such as naproxen and ibuprofen. In addition, the analgesic efficacy of rofecoxib has been demonstrated to be superior to that of the opioid combination of codeine 60 mg/acetaminophen 600 mg in an acute dental pain model. For the treatment of acute pain, the efficacy of rofecoxib was further demonstrated in a study of patients who had undergone orthopedic surgery. Rofecoxib has been found to be as effective as naproxen sodium and more effective than placebo in studies evaluating its use for the treatment of primary dysmenorrhea. In patients with osteoarthritis (OA) of the knee or hip, rofecoxib is superior to placebo and similar to diclofenac and ibuprofen in relieving OA pain and improving physical function. Rofecoxib has also been shown to be superior to acetaminophen and celecoxib after 6 weeks of treatment for OA. The efficacy of rofecoxib has also been demonstrated in patients with rheumatoid arthritis and low back pain. The advantages of using COX-2-specific NSAIDs include convenient once-daily dosing schedule and improved safety compared with traditional NSAIDs. Two large outcomes studies, VIGOR and CLASS, have shown that gastric mucosal ulceration occurs significantly less often in patients taking COX-2-specific inhibitors than in those treated with ibuprofen, diclofenac, or naproxen and occurs with a similar incidence to that of placebo. Absence of any effect on platelet aggregation and bleeding time further distinguishes these agents from traditional NSAIDs. Because COX-2-specific inhibitors do not have an antiplatelet effect, they cannot be used as a substitute for low-dose aspirin for cardiovascular prophylaxis. Rofecoxib is a safe and highly effective alternative to previously available NSAIDs and should be considered for the treatment of acute pain conditions in adult patients, especially those at risk for developing gastrointestinal complications. It is preferred in the perioperative setting because of its analgesic efficacy and lack of platelet effects. Because of its more favorable gastrointestinal toxicity profile compared with nonselective NSAIDs, rofecoxib is safer in patients, especially older patients, for whom chronic anti-inflammatory or analgesic therapy is indicated.

Rofecoxib-induced instant aquagenic wrinkling of the palms

An 18-year-old woman presented with a 3-week complaint of exaggerated palmar wrinkling and swelling following brief exposure (1-2 minutes) of her hands to water. She had a history of mixed connective tissue disease and had been started on rofecoxib therapy 1 month prior to the onset of her skin symptoms. Discontinuation of rofecoxib was followed by resolution of symptoms within a period of 3 weeks. Similar palmar skin changes following water exposure have been reported to occur in cystic fibrosis and are thought to be due to increased salt content of the skin and secondary increased water-binding capacity. Rofecoxib is a selective COX-2 inhibitor that has been shown to increase sodium reabsorption in the kidney via effects on prostaglandin E2 and the renal vasculature. The COX-2 protein is also expressed in keratinocytes and plays a role in keratinocyte differentiation. Prostaglandin E2 also plays a role in keratinocyte proliferation and differentiation. Thus rofecoxib may cause increased sodium reabsorption in the skin, as it does in the kidney. The rofecoxib-associated elevation in skin sodium may increase keratin water-binding capacity and cause exaggerated aquagenic wrinkling of the skin, as occurs in cystic fibrosis.

Rofecoxib inhibits cyclooxygenase 2 expression and activity and reduces cell proliferation in Barrett's esophagus

BACKGROUND & AIMS

Cyclooxygenase 2 (COX-2) is overexpressed in Barrett's esophagus and adenocarcinoma and up-regulated by acid or bile salt exposure. COX-2 inhibition with the selective inhibitor rofecoxib may be important in chemoprevention of esophageal adenocarcinoma by decreasing cell proliferation.

METHODS

Biopsy specimens of esophagus, Barrett's esophagus, and duodenum were obtained at baseline from 12 patients and were compared with biopsy specimens obtained after 10 days of therapy with rofecoxib 25 mg orally daily. All patients were maintained asymptomatic on their proton pump inhibitor therapy throughout the study. COX-2 expression, proliferating cell nuclear antigen (PCNA) expression (proliferation marker), and prostaglandin E2 (PGE2) biopsy content (marker of COX activity) were assessed by immunoblotting and enzyme immunoabsorbence assays.

RESULTS

At baseline, COX-2 expression was 3-fold higher in Barrett's esophagus than esophagus and duodenum (P < 0.05). After rofecoxib therapy, COX-2 expression in Barrett's esophagus decreased by 77% (P < 0.005). Similarly at baseline, PGE2 content was 2-fold higher in Barrett's esophagus than esophagus or duodenum. After rofecoxib therapy, PGE2 content decreased in Barrett's esophagus by 59% (P < 0.005). At baseline, PCNA expression was also 2-fold higher in Barrett's esophagus than squamous esophagus and duodenum (P < 0.005). After rofecoxib therapy, PCNA expression in Barrett's esophagus decreased by 62.5% (P < 0.005).

CONCLUSIONS

Rofecoxib 25 mg orally once daily reduces COX-2 expression, PGE2 release, and cell proliferation in Barrett's esophagus. Together with acid suppressive therapy, rofecoxib may be a promising chemoprevention agent against dysplasia and esophageal adenocarcinoma.

A multinational randomized, controlled, clinical trial of etoricoxib in the treatment of rheumatoid arthritis [ISRCTN25142273]

BACKGROUND

Etoricoxib is a highly selective COX-2 inhibitor which was evaluated for the treatment of rheumatoid arthritis (RA).

METHODS

Double-blind, randomized, placebo and active comparator-controlled, 12-week study conducted at 67 sites in 28 countries. Eligible patients were chronic NSAID users who demonstrated a clinical worsening of arthritis upon withdrawal of prestudy NSAIDs. Patients received either placebo, etoricoxib 90 mg once daily, or naproxen 500 mg twice daily (2:2:1 allocation ratio). Primary efficacy measures included direct assessment of arthritis by counts of tender and swollen joints, and patient and investigator global assessments of disease activity. Key secondary measures included the Stanford Health Assessment Questionnaire, patient global assessment of pain, and the percentage of patients who achieved ACR20 responder criteria response (a composite of pain, inflammation, function, and global assessments). Tolerability was assessed by adverse events and routine laboratory evaluations.

RESULTS

1171 patients were screened, 891 patients were randomized (N = 357 for placebo, N = 353 for etoricoxib, and N = 181 for naproxen), and 687 completed 12 weeks of treatment (N = 242 for placebo, N = 294 for etoricoxib, and N = 151 for naproxen). Compared with patients receiving placebo, patients receiving etoricoxib and naproxen showed significant improvements in all efficacy endpoints (p<0.05). Treatment responses were similar between the etoricoxib and naproxen groups for all endpoints. The percentage of patients who achieved ACR20 responder criteria response was 41% in the placebo group, 59% in the etoricoxib group, and 58% in the naproxen group. Etoricoxib and naproxen were both generally well tolerated.

CONCLUSIONS

In this study, etoricoxib 90 mg once daily was more effective than placebo and similar in efficacy to naproxen 500 mg twice daily for treating patients with RA over 12 weeks. Etoricoxib 90 mg was generally well tolerated in RA patients.

Cyclooxygenase-2: a therapeutic target

Cyclooxygenase (COX), also known as prostaglandin endoperoxide synthase, is the key enzyme required for the conversion of arachidonic acid to prostaglandins. Two COX isoforms have been identified, COX-1 and COX-2. In many situations, the COX-1 enzyme is produced constitutively (e.g., in gastric mucosa), whereas COX-2 is highly inducible (e.g., at sites of inflammation and cancer). Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both enzymes, and a new class of COX-2 selective inhibitors (COXIBs) preferentially inhibit the COX-2 enzyme. This review summarizes our current understanding of the role of COX-1 and COX-2 in normal physiology and disease.