Gastrointestinal safety of coxibs: systematic review and meta-analysis of observational studies on selective inhibitors of cyclo-oxygenase 2

Prior meta-analyses have shown a higher gastrointestinal risk of nonselective NSAIDs versus placebo and a lower gastrointestinal risk of coxibs versus nonselective NSAIDs. However, the available data about gastrointestinal risk for coxibs versus placebo are scarce. The aim of this study was to review the current evidence on the use of coxibs and to evaluate the risk of gastrointestinal adverse outcomes (GAO) associated with coxibs versus nonexposed. Search was conducted on PubMed and Embase databases. We selected cohort observational, case-control, nested case-control and case-crossover studies that reported the risk of GAO associated with coxibs versus nonexposed as relative risk (RR), odds ratio (OR), hazard ratio (HR) or incidence rate ratio (IRR). It was estimated the pooled RR and the 95% confidence interval (CI) for coxibs both individually and as a whole by the DerSimonian and Laird method. Twenty-eight studies met inclusion criteria. Overall, coxibs were associated with a significant increment in the risk of GAO [RR 1.64 (95% CI 1.44-1.86)]. The analysis by individual drugs showed that etoricoxib [RR 4.85 (95% CI 2.64-8.93)] presented the highest gastrointestinal risk, followed by rofecoxib [RR 2.02 (95% CI 1.56-2.61)] and celecoxib [RR 1.53 (95% CI 1.19-1.97)]. Gastrointestinal risk was also high for the subgroups aged <65 years and low-dose coxibs. The use of coxibs is associated with a statistically significant increased risk of GAO, which would be high even for low-dose coxibs and <65-year-old subgroups. The risk would be higher for etoricoxib than for celecoxib and rofecoxib.

Cost-effectiveness analyses of osteoarthritis oral therapies: a systematic review

BACKGROUND

Cost-effectiveness analyses (CEAs) have been performed for oral non-disease-altering osteoarthritis (OA) treatments for well over a decade. During that period the methods for performing these analyses have evolved as pharmacoeconomic methods have advanced, new treatments have been introduced, and the knowledge of associated adverse events (AEs) has improved.

OBJECTIVE

The objective of this systematic review was to trace the development of CEAs for oral non-disease-altering treatments in OA.

METHODS

A systematic search for CEAs of OA oral treatments was performed of the English-language medical literature using the following databases: PubMed, EMBASE, MEDLINE In-Process, EconLit, and Cochrane. Key requirements for inclusion were that the population described patients with OA or arthritis and that the analysis reported at least one incremental cost-effectiveness ratio. Each identified publication was assessed for inclusion. Thirteen characteristics and all AEs appearing in each included CEA were extracted and organized. Reference lists from these CEAs were also searched. A chronology of key CEAs in the field was compiled, noting the characteristics that advanced the state of the art in modeling oral OA treatments.

RESULTS

Thirty publications of 28 CEAs were identified and evaluated. Developments in CEAs included an expanded set of comparators that broadened from non-steroidal anti-inflammatory drugs (NSAIDs) only to NSAIDs plus gastroprotective agents, cyclooxygenase-2 inhibitors, and opioids. In turn, AEs expanded from gastrointestinal (GI) events to also include cardiovascular (CV) and neurological events. Efficacy, which initially was presumed to be equivalent for all treatments, evolved to treatment-specific efficacies. Decision-tree analyses were generally replaced by Markov models or, occasionally, stochastic or discrete event simulation. Finally, outcomes have progressed from GI-centric measures to also include quality-adjusted life-years.

CONCLUSION

Methods used by CEAs of oral non-disease-altering OA treatments have evolved in response to changing treatments with different safety profiles and efficacies as well as technical advances in the application of decision science to health care.

Comparison of gastrointestinal adverse effects between cyclooxygenase-2 inhibitors and non-selective, non-steroidal anti-inflammatory drugs plus proton pump inhibitors: a systematic review and meta-analysis

BACKGROUND

There are conflicting and inconsistent data regarding the gastrointestinal (GI) protective effect of cyclooxygenase-2 (COX-2) inhibitors and of non-steroidal anti-inflammatory drugs (NSAIDs) plus proton-pump inhibitors (PPI).

AIM

To compare the adverse GI effects between COX-2 inhibitors and NSAIDs plus PPI.

METHODS

We performed a systematic review of randomized trials comparing GI adverse effects between COX-2 inhibitors and NSAID plus PPI. Trials were identified in MEDLINE, EMBASE, and the Cochrane Library. Primary outcomes were major GI complications including hemorrhage, perforation, and obstruction.

RESULTS

A total of nine trials involving 7,616 participants from 2002 to 2011 were included. All trials were randomized, double blinded, and placebo-controlled with moderate to high quality. COX-2 inhibitors were found to have significantly reduced the risk of major GI events, including perforation, obstruction, and bleeding (relative risk or RR 0.38, 95 % confidence interval or CI 0.25-0.56, p < 0.001); however, the benefit was significant only for patients who were at high risk for NSAID-related GI complications and long-term users. Additionally, the risk of diarrhea (RR 0.56, 95 % CI 0.35-0.9, p 0.02) and withdrawal (RR 0.77, 95 % CI 0.62-0.94, p 0.01) was significantly lower in use of COX-2 inhibitors, while the rate of dyspepsia was higher (RR 1.58, 95 % CI 1.26-1.98, p < 0.001).

CONCLUSIONS

COX-2 inhibitors significantly reduced the risk of perforation, obstruction, bleeding, diarrhea, and withdrawal due to GI adverse events, while the risk of dyspepsia was lower with NSAIDs plus PPI.

Cost-utility analysis of duloxetine in osteoarthritis: a US private payer perspective

BACKGROUND

Duloxetine has recently been approved in the USA for chronic musculoskeletal pain, including osteoarthritis and chronic low back pain. The cost effectiveness of duloxetine in osteoarthritis has not previously been assessed. Duloxetine is targeted as post first-line (after acetaminophen) treatment of moderate to severe pain.

OBJECTIVE

The objective of this study was to estimate the cost effectiveness of duloxetine in the treatment of osteoarthritis from a US private payer perspective compared with other post first-line oral treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), and both strong and weak opioids.

METHODS

A cost-utility analysis was performed using a discrete-state, time-dependent semi-Markov model based on the National Institute for Health and Clinical Excellence (NICE) model documented in its 2008 osteoarthritis guidelines. The model was extended for opioids by adding titration, discontinuation and additional adverse events (AEs). A life-long time horizon was adopted to capture the full consequences of NSAID-induced AEs. Fourteen health states comprised the structure of the model: treatment without persistent AE, six during-AE states, six post-AE states and death. Treatment-specific utilities were calculated using the transfer-to-utility method and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores from a meta-analysis of osteoarthritis clinical trials of 12 weeks and longer. Costs for 2011 were estimated using Red Book, The Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project database, the literature and, sparingly, expert opinion. One-way and probabilistic sensitivity analyses were undertaken, as well as subgroup analyses of patients over 65 years old and a population at greater risk of NSAID-related AEs.

RESULTS

In the base case the model estimated naproxen to be the lowest total-cost treatment, tapentadol the highest cost, and duloxetine the most effective after considering AEs. Duloxetine accumulated 0.027 discounted quality-adjusted life-years (QALYs) more than naproxen and 0.013 more than oxycodone. Celecoxib was dominated by naproxen, tramadol was subject to extended dominance, and strong opioids were dominated by duloxetine. The model estimated an incremental cost-effectiveness ratio (ICER) of US$47,678 per QALY for duloxetine versus naproxen. One-way sensitivity analysis identified the probabilities of NSAID-related cardiovascular AEs as the inputs to which the ICER was most sensitive when duloxetine was compared with an NSAID. When compared with a strong opioid, duloxetine dominated the opioid under nearly all sensitivity analysis scenarios. When compared with tramadol, the ICER was most sensitive to the costs of duloxetine and tramadol. In subgroup analysis, the cost per QALY for duloxetine versus naproxen fell to US$24,125 for patients over 65 years and to US$18,472 for a population at high risk of cardiovascular and gastrointestinal AEs.

CONCLUSION

The model estimated that duloxetine was potentially cost effective in the base-case population and more cost effective for subgroups over 65 years or at high risk of NSAID-related AEs. In sensitivity analysis, duloxetine dominated all strong opioids in nearly all scenarios.

A comparison of cost effectiveness using data from randomized trials or actual clinical practice: selective cox-2 inhibitors as an example

BACKGROUND

Data on absolute risks of outcomes and patterns of drug use in cost-effectiveness analyses are often based on randomised clinical trials (RCTs). The objective of this study was to evaluate the external validity of published cost-effectiveness studies by comparing the data used in these studies (typically based on RCTs) to observational data from actual clinical practice. Selective Cox-2 inhibitors (coxibs) were used as an example.

METHODS AND FINDINGS

The UK General Practice Research Database (GPRD) was used to estimate the exposure characteristics and individual probabilities of upper gastrointestinal (GI) events during current exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) or coxibs. A basic cost-effectiveness model was developed evaluating two alternative strategies: prescription of a conventional NSAID or coxib. Outcomes included upper GI events as recorded in GPRD and hospitalisation for upper GI events recorded in the national registry of hospitalisations (Hospital Episode Statistics) linked to GPRD. Prescription costs were based on the prescribed number of tables as recorded in GPRD and the 2006 cost data from the British National Formulary. The study population included over 1 million patients prescribed conventional NSAIDs or coxibs. Only a minority of patients used the drugs long-term and daily (34.5% of conventional NSAIDs and 44.2% of coxibs), whereas coxib RCTs required daily use for at least 6-9 months. The mean cost of preventing one upper GI event as recorded in GPRD was US$104k (ranging from US$64k with long-term daily use to US$182k with intermittent use) and US$298k for hospitalizations. The mean costs (for GPRD events) over calendar time were US$58k during 1990-1993 and US$174k during 2002-2005. Using RCT data rather than GPRD data for event probabilities, the mean cost was US$16k with the VIGOR RCT and US$20k with the CLASS RCT.

CONCLUSIONS

The published cost-effectiveness analyses of coxibs lacked external validity, did not represent patients in actual clinical practice, and should not have been used to inform prescribing policies. External validity should be an explicit requirement for cost-effectiveness analyses.

Cost-utility of celecoxib use in different treatment strategies for osteoarthritis and rheumatoid arthritis from the Quebec healthcare system perspective

OBJECTIVE

To assess the cost-utility of celecoxib in three treatment strategies for arthritis in Quebec, considering both upper gastrointestinal (GI) and cardiovascular (CV) events.

METHODS

A Markov analytic framework was used to model patients with osteoarthritis and rheumatoid arthritis at low/average and high risk of GI and CV toxicity over 5 years with monthly cycles. Treatment strategies were modelled in line with Canadian clinical practice. In first-line treatment, patients started on celecoxib; second-line, patients started on a non-selective non-steroidal anti-inflammatory drug (NSAID) and switched to celecoxib after a first GI event; third-line, patients started on a non-selective NSAID, added a proton pump inhibitor (PPI) after a first GI event, and switched to celecoxib after a second GI event (while maintaining the PPI). Model inputs were determined through comprehensive literature searches (MEDLINE and EMBASE) from 1995 to 2006. Included studies evaluated GI (dyspepsia, uncomplicated and complicated ulcers, death) and CV (myocardial infarction, stroke, death) events. Drug and procedure costs were derived from Canadian published sources (Can$2005).

RESULTS

Total costs per patient for celecoxib first-, second-, and third-line treatment were Can$4,790, $3,390, and $3,466, and total quality-adjusted life-years (QALY) were 3.251, 3.231, and 3.230, respectively. In all risk categories, celecoxib second-line was less costly and as effective as celecoxib third-line, producing savings to the healthcare system. Although celecoxib first-line generated incremental expenditures versus celecoxib second-line, it was also more effective. The resulting cost-utility ratio for the high-risk population was Can$54,696/QALY. Based on this analytical approach, a treatment strategy where celecoxib is used before the combination of a non-selective NSAID plus a PPI possesses cost advantages for the Quebec provincial drug programme. One-way sensitivity analysis (varying GI and CV event rates, utilities, and cost) generally showed second-line treatment with celecoxib as the dominant strategy compared with third-line treatment with celecoxib.

CONCLUSION

Although effectiveness of second- and third-line celecoxib use is similar, total cost is lower for second-line. These results suggest that the use of celecoxib before the combination of a non-selective NSAID plus a PPI is relatively cost-effective in the treatment of arthritis pain and support the full benefit listing of celecoxib in Quebec's drug programme.

Cost-effectiveness analysis for joint pain treatment in patients with osteoarthritis treated at the Instituto Mexicano del Seguro Social (IMSS): Comparison of nonsteroidal anti-inflammatory drugs (NSAIDs) vs. cyclooxygenase-2 selective inhibitors

Background

Osteoarthritis (OA) is one of the main causes of disability worldwide, especially in persons >55 years of age. Currently, controversy remains about the best therapeutic alternative for this disease when evaluated from a cost-effectiveness viewpoint. For Social Security Institutions in developing countries, it is very important to assess what drugs may decrease the subsequent use of medical care resources, considering their adverse events that are known to have a significant increase in medical care costs of patients with OA. Three treatment alternatives were compared: celecoxib (200 mg twice daily), non-selective NSAIDs (naproxen, 500 mg twice daily; diclofenac, 100 mg twice daily; and piroxicam, 20 mg/day) and acetaminophen, 1000 mg twice daily. The aim of this study was to identify the most cost-effective first-choice pharmacological treatment for the control of joint pain secondary to OA in patients treated at the Instituto Mexicano del Seguro Social (IMSS).

Methods

A cost-effectiveness assessment was carried out. A systematic review of the literature was performed to obtain transition probabilities. In order to evaluate analysis robustness, one-way and probabilistic sensitivity analyses were conducted. Estimations were done for a 6-month period.

Results

Treatment demonstrating the best cost-effectiveness results [lowest cost-effectiveness ratio $17.5 pesos/patient ($1.75 USD)] was celecoxib. According to the one-way sensitivity analysis, celecoxib would need to markedly decrease its effectiveness in order for it to not be the optimal treatment option. In the probabilistic analysis, both in the construction of the acceptability curves and in the estimation of net economic benefits, the most cost-effective option was celecoxib.

Conclusion

From a Mexican institutional perspective and probably in other Social Security Institutions in similar developing countries, the most cost-effective option for treatment of knee and/or hip OA would be celecoxib.

Assessing the cost-effectiveness of COX-2 specific inhibitors for arthritis in the Veterans Health Administration

OBJECTIVE

This study was designed to assess the cost-effectiveness of cyclooxygenase-2 specific (COX-2) inhibitors (rofecoxib and celecoxib) over nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) in high-risk arthritis patients from the perspective of the Veterans Health Administration (VA).

METHODS

This literature-based economic analysis (with data summarized from MEDLINE-indexed and other published sources, FDA reports, and data on file at VA San Diego Healthcare System) compared rofecoxib and celecoxib to NSAIDS in two arthritis patient populations considered at higher risk of developing clinically significant upper gastrointestinal events (CSUGIEs): (1) patients of any age with previous medical history of perforation/ulcer/bleed (PUB); and (2) patients 65 years and older (regardless of history of PUB). Two outcome measures were reported: (1) incremental cost per CSUGIE averted over 1 year; and (2) incremental cost per quality-adjusted life-year (QALY) gained, considering both the mortality and morbidity associated with gastrointestinal (including CSUGIEs) and cardiovascular-related adverse events. When possible, costs were modeled to reflect the VA perspective. Sensitivity analyses were conducted to test the robustness of the analysis.

RESULTS

Compared to NSAIDS, rofecoxib and celecoxib increased costs but reduced the incidence of CSUGIE. Cost per CSUGIE avoided were $7476 and $16,379 (in patients with a PUB history) and $14,294 and $18,376 (in patients aged > or = 65 years) for celecoxib and rofecoxib, respectively. In both populations, celecoxib was associated with a cost per QALY less than $50,000. In contrast, rofecoxib was found to cost more and result in a net QALY loss, due in particular to the increase in the risk of cardiovascular complications, and was therefore considered cost-ineffective. Results were most dependent on assumptions about the incidence of cardiovascular events and CSUGIE and the COX-2 inhibitors' acquisition price.

CONCLUSIONS

This analysis suggests that COX-2 inhibitors may be cost-effective from the perspective of the VA. However, cost-effectiveness appears to depend less on the specific characteristics of the high-risk target population considered but more on the agent evaluated. Celecoxib appears to be an alternative to traditional NSAIDs in the patient populations studied.

Assessment of the safety of selective cyclo-oxygenase-2 inhibitors: where are we in 2003?

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs worldwide despite their well-documented adverse gastrointestinal (GI) effects. The risk of developing a severe GI event varies from patient to patient and NSAID to NSAID. Selective cyclo-oxygenase-2 inhibitors (coxibs) have been designed to have similar efficacy but less GI toxicity than traditional NSAIDs, and have been shown to have an improved GI tolerability and less adverse events across a range of different GI safety assessments. In clinical trials, particularly VIGOR and CLASS, rofecoxib and celecoxib, respectively, significantly reduce the risk of ulcers and ulcer complications than nonselective NSAID comparators with ulcer rates comparable to placebo. The real benefit of a coxib comes from the sparing of the thromboxane and hence preservation of normal platelet function. Thus, there is less risk of bleeding with selective inhibition of COX-2, which is the most common and serious complication of non-selective NSAIDs. Moreover, bleeding can occur anywhere in the GI tract. Although some concern has been raised about the cardiovascular safety of coxibs, when used in recommended doses, there is no convincing evidence that patients treated with a coxib have an increased risk of cardiovascular thrombotic events. Different approaches have been advocated to minimize NSAID-related GI toxicity. Choice of less harmful NSAIDs such as coxib has been one of the strategies promoted in guidelines. The introduction of coxibs with a higher benefit-risk ratio has dramatically changed the therapeutic scenario for anti-inflammatory treatment in the clinical practice.

Valdecoxib: a review

BACKGROUND

Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac, ibuprofen, naproxen, and related agents are nonselective inhibitors of both cyclooxygenase-1 (COX-1) and COX-2, which catalyze prostaglandin synthesis. This inhibition accounts not only for the analgesic, anti-inflammatory, and antipyretic effects of these agents, but also for side effects such as gastric mucosal damage and renal toxicity. Substantial evidence suggests that sparing COX-1 is advantageous for gastric safety.

OBJECTIVE

This article reviews available information on the new COX-2-selective inhibitor valdecoxib, including its clinical pharmacology, pharmacokinetics, adverse effects, potential drug interactions, and contraindications and warnings. Results of clinical trials of efficacy and tolerability are summarized.

METHODS

Articles for inclusion in this review were identified through searches of PubMed and MEDLINE (1966-December 2002) and International Pharmaceutical Abstracts (1970-December 2002). Search terms included valdecoxib, Bextra, COX-2-selective inhibitors, coxibs, and selective cyclooxygenase inhibitors. The reference lists of identified articles were reviewed for additional publications. Product information was also obtained from the manufacturer of valdecoxib.

RESULTS

Fourteen clinical studies involving > 4000 patients have been conducted. Valdecoxib was significantly more effective than placebo in the treatment of adult rheumatoid arthritis, osteoarthritis, pain associated with primary dysmenorrhea, and postoperative pain. Valdecoxib was comparable to naproxen for the treatment of rheumatoid arthritis in 1 study and equivalent to naproxen for the treatment of osteoarthritis in other studies. Three studies found valdecoxib comparable to naproxen sodium for the relief of moderate to severe pain due to primary dysmenorrhea, and others found valdecoxib comparable to oxycodone plus acetaminophen and significantly more effective than rofecoxib for the relief of pain associated with dental surgery (P < 0.05). Four safety studies and 2 reviews of clinical trials documented lower rates of endoscopic gastroduodenal ulcer formation with valdecoxib compared with ibuprofen, naproxen, and diclofenac (P < 0.001 to P < 0.05). Valdecoxib did not inhibit platelet function (bleeding time and platelet aggregation) in healthy adults or in the elderly. Due to the risk of potentially serious skin and allergic reactions, patients who are allergic to sulfa-containing drugs should not take valdecoxib. The drug should be discontinued immediately if rash develops.

CONCLUSIONS

In clinical trials, valdecoxib was effective for the treatment of osteoarthritis, rheumatoid arthritis, and moderate to severe pain associated with primary dysmenorrhea. As with the other COX-2-selective inhibitors (celecoxib and rofecoxib), valdecoxib appears to produce less gastrointestinal toxicity than conventional nonselective NSAIDs, although some of the relevant clinical studies have been published only as abstracts. Use of valdecoxib should be reserved for patients at risk for NSAID-induced gastrointestinal problems.