Association between nonnaproxen NSAIDs, COX-2 inhibitors and hospitalization for acute myocardial infarction among the elderly: a retrospective cohort study

Cardiovascular safety of non-steroidal anti-inflammatory drugs in chronic inflammatory rheumatic diseases

Rheumatic diseases (RD), such as rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis, psoriatic arthritis, vasculitis, gout are associated with increase in cardiovascular morbidity and mortality. The main causes of increased cardiovascular risk are inflammatory heart and vascular lesions, accelerated progression of atherosclerosis and side effects of drug therapy. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in clinical practice and are on the list of the most prescribed medications. It is known that NSAIDs have a negative effect on the cardiovascular system (CVS). However NSAIDs may decrease the intensity of inflammation, which is an independent risk risk factor for CVS pathology. Therefore in patients with RD it is theoretically possible to reduce the severity of cardiovascular side effects when using NSAIDs. The article discusses the issues of NSAID's cardiovascular safety, the molecular mechanisms underlying the negative effect of them on CVS, critically evaluated the results of main studies concerning the cardiovascular safety of NSAIDs in chronic inflammatory diseases.

Comparative cardiovascular safety of nonsteroidal anti-inflammatory drugs in patients with hypertension: a population-based cohort study

AIMS

Previous studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with higher cardiovascular risks. However, few have been active comparison studies that directly assessed the potential differential cardiovascular risk between NSAID classes or across individual NSAIDs. We compared the risk of major cardiovascular events between cyclooxygenase 2 (COX-2)-selective and nonselective NSAIDs in patients with hypertension.

METHODS

We conducted a cohort study of patients with hypertension who initiated COX-2-selective or nonselective NSAIDs in a population-based Taiwanese database. The outcomes included hospitalization for the following major cardiovascular events: ischaemic stroke, acute myocardial infarction, congestive heart failure, transient ischaemic attack, unstable angina or coronary revascularization. We followed patients for up to 4 weeks, based on the as-treated principle. We used inverse probability weighting to control for baseline and time-varying covariates, and estimated the on-treatment hazard ratios (HRs) and 95% conservative confidence interval (CIs).

RESULTS

We identified 2749 eligible COX-2-selective NSAID users and 52 880 eligible nonselective NSAID users. The HR of major cardiovascular events comparing COX-2-selective with nonselective NSAIDs after adjusting for baseline and time-varying covariates was 1.07 (95% CI 0.65, 1.74). We did not observe a differential risk when comparing celecoxib to diclofenac (HR 1.17; 95% CI 0.61, 2.25), ibuprofen (HR 1.36; 95% CI 0.58, 3.18) or naproxen (HR 0.75; 95% CI 0.23, 2.44). There was an increased risk with COX-2-selective NSAIDs, however, when comparing COX-2-selective NSAIDs with mefenamic acid (HR 2.11; 95% CI 1.09, 4.09).

CONCLUSIONS

Our results provide important information about the comparative cardiovascular safety of NSAIDs in patients with hypertension.

Ischemic Colitis as a Complication of Medication Use: An Analysis of the Federal Adverse Event Reporting System

BACKGROUND

More than one decade ago, rising cases of ischemic colitis (IC) prompted the Federal Drug Administration to revoke alosetron's approval as treatment of irritable bowel syndrome (IBS). The aim of this study was to identify medical therapies associated with development of IC.

METHODS

The Federal Adverse Event Reporting System was queried for the time between January 2004 and September 2015. We identified reports listing IC as treatment complication and extracted suspected causative and concomitantly administered drugs, indications for their use and outcomes.

RESULTS

After eliminating duplicates, we found 2811 cases of IC (68.4 % women; 59.4 ± 0.4 years). Patients with IBS accounted for 3.9 % of the cases, mostly attributed to tegaserod or alosetron. Chemotherapeutic and immunosuppressive drugs, sex hormones, and anticoagulants were the most commonly suspected causes. Bisphosphonates, nonsteroidal anti-inflammatory drugs, antipsychotics, triptans, interferon therapy, and laxative use prior to colonoscopy were among the more commonly listed treatments. In 8 %, the adverse event contributed to the patient's death with male sex and older age predicting fatal outcomes.

CONCLUSION

Beyond confirming known risks of IC, the results identified several potential culprits of ischemic colitis. This information may not only explain the development of this serious adverse event, but could also guide treatment decisions, cautioning healthcare providers when considering these agents in persons with known risk factors or other drugs that may increase their risk of IC.

A pathway to improved prospective observational post-authorization safety studies

Randomized controlled trials (RCTs) are the gold standard for assessing the efficacy of drugs but not necessarily so for drug safety where inadequate power to detect either multiple or rare adverse events is a major handicap. Furthermore, the conditions under which drugs are approved for market use are often different from the settings in actual use. Indeed, with their control mechanisms, trials are by design largely inadequate for the identification of potential safety signals, especially of the rare type, hence the value of postmarketing surveillance and risk management plan-based activities. Today, clinical trials constitute only a part of the research that goes into assessing the safety of drugs. Observational studies, where the investigators merely collect data on treatments received by patients and their health status in routine clinical practice are increasing in uptake because they reflect the real-life utility of drugs, despite the absence of random treatment assignment. Although such studies generally provide less compelling evidence than RCTs, they can be far more useful to drug safety assessment activities than generally acknowledged. An increasing number of post-authorization safety studies (PASS) within the European Medicines Agency's jurisdiction are of the observational type - considered perhaps as more appropriate vehicles for exploring and documenting how products perform in the real world. A similar trend is emerging in the US following the FDA Amendments Act of 2007; since early 2010, an increasing number of post-approval commitments mandated by the FDA include observational studies. However, despite this pattern, not much is known about ongoing efforts to address many of the recognized inadequacies associated with existing methodologies and practices currently adopted in observational PASS. This current opinion presents an overview of some of the main challenges we face in prospective observational PASS, mainly from practical experience, and proposes certain steps for improvement.

A quantitative evaluation of the regulatory assessment of the benefits and risks of rofecoxib relative to naproxen: an application of the incremental net-benefit framework

PURPOSE

To undertake a quantitative benefit-risk analysis of rofecoxib relative to naproxen using an incremental net-benefit (INB) analysis from the societal perspective, using the same data evaluated by the Health Canada and US FDA expert advisory panels.

METHODS

We developed a discrete event simulation model to calculate the INB of rofecoxib relative to naproxen in arthritis patients over a 1-year time horizon. All outcomes were weighted using societal utilities for each health state which facilitated the use of quality-adjusted life years (QALYs) as the outcome. Probability distributions were incorporated for each model parameter to facilitate a probabilistic analysis using second-order Monte Carlo simulation.

RESULTS

In the base case analysis, the mean INB (SD) of rofecoxib relative to naproxen was 0.0002 (0.415) QALYs per patient over 12 months of treatment, or 0.2 QALYs per 1000 patients treated. The probabilistic sensitivity analysis resulted in a mean INB of 0.0022 QALYs (95%CI -0.0005, 0.0051). Overall, the INB associated with rofecoxib relative to naproxen was ≥0 in 94% of the iterations of the model.

CONCLUSIONS

This analysis illustrates the application of the incremental net-benefit framework to quantitative benefit-risk evaluation, and suggests that the potential benefits of rofecoxib outweigh the potential harms relative to naproxen over 1 year from the societal perspective under the assumptions of this model.

Utilization patterns of extended-release niacin in Canada: analysis of an administrative claims database

BACKGROUND AND OBJECTIVE

To evaluate utilization patterns with extended-release niacin (ERN) compared with those observed with other lipid-modifying drugs (LMDs).

METHODS

A random sample of 17% of patients who had at least one LMD dispensation between January 2004 and February 2007 was obtained from the administrative databases of the Régie de l'assurance maladie du Quebec. Primary outcomes included drug adherence, persistence and discontinuation with ERN and other LMDs, and daily maintenance dose attainment (1500 mg and 2000 mg) with ERN at one-year follow-up. Adherence was defined as the sum of days of all dispensations divided by the total number of days of follow-up. Persistence was defined as renewal of prescription before the end of dispensation plus a grace period (50% prescription duration).

RESULTS

Among 26,862 patients, the majority received statins (73.4%), whereas 867 (3.2%) received ERN. The mean age of ERN patients was 62 years and 75% were male. After one year, adherence with ERN was below that of statins (62.0% versus 74.9%), as was persistence (36.1% versus 46.7%), while discontinuation rates were higher (64.0% versus 53.3%). The median time until discontinuation for ERN was shorter than for statins (66 days versus 99 days). After one year, 5.8% of patients were taking 1500 mg or more and 3.2% were on 2000 mg.

CONCLUSIONS

In the present cohort of patients from regular clinical practice in Quebec, ERN use was associated with low prescription rates, inferior adherence and persistence compared with other LMDs, high discontinuation rates, and very low 2000 mg dose attainment.

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.

Differences in persistence among different weekly oral bisphosphonate medications

SUMMARY

We evaluated the differences in persistence with weekly oral bisphosphonate therapy according to the initial drug. Persistence to weekly oral preparations remains suboptimal, particularly in patients who receive generic alendronate. Alternative solutions are needed to improve the real life effectiveness of osteoporosis therapies.

INTRODUCTION

Poor persistence is widespread with oral osteoporosis (OP) therapy. The objective of this study was to evaluate the persistence among OP patients started on weekly oral bisphosphonates (BP).

METHODS

Patients newly initiated on branded risedronate, branded alendronate, or generic alendronate once weekly were selected from the Régie de l'Assurance Maladie du Québec databases. The cohort included patients with and without a previous OP fracture. The probability and the risk factors for early discontinuation were estimated using Cox regression models.

RESULTS

The study cohort included 32,804 patients. After 1 year, a significant difference in persistence on oral BP therapy was found. The patients started on branded risedronate were 11% more likely to stop OP therapy than patients started on branded alendronate. Risk of discontinuation doubled in patients initiated with generic alendronate compared to patients started on branded alendronate. Male gender was associated with a 25% increase risk of early discontinuation. No statistical association was found between previous OP fracture and early discontinuation.

CONCLUSION

This study provides further evidence of poor persistence to newly initiated oral weekly BP therapies, particularly for the patients started on generic alendronate.

Clinical use and pharmacological properties of selective COX-2 inhibitors

Selective COX-2 inhibitors (coxibs) are approved for the relief of acute pain and symptoms of chronic inflammatory conditions such as osteoarthritis (OA) and rheumatoid arthritis (RA). They have similar pharmacological properties but a slightly improved gastrointestinal (GI) safety profile if compared to traditional nonsteroidal anti-inflammatory drugs (tNSAIDs). However, long-term use of coxibs can be associated with an increased risk for cardiovascular (CV) adverse events (AEs). For this reason, two coxibs were withdrawn from the market. Currently celecoxib, etoricoxib, and lumiracoxib are used. These three coxibs differ in their chemical structure and selectivity for COX-2, which might explain some of their pharmacological features. Following oral administration, the less lipophilic celecoxib has a lower bioavailability (20-40%) than the other two coxibs (74-100%). All are eliminated by hepatic metabolism involving mainly CYP2C9 (celecoxib, lumiracoxib) and CYP3A4 (etoricoxib). Elimination half-life varies from 5 to 8 h (lumiracoxib), 11 to 16 h (celecoxib) and 19 to 32 h (etoricoxib). In patients with liver disease, plasma levels of celecoxib and etoricoxib are increased about two-fold. Clinical efficacies of the coxibs are comparable to tNSAIDs. There is an ongoing discussion about whether the slightly better GI tolerability (which is lost if acetylsalicylic acid is coadministered) of the coxibs is offset by their elevated risks for CV AEs (also seen with tNSAIDs other than naproxen), which apparently increase with dose and duration of exposure. In addition, the higher costs for coxibs (if compared to tNSAIDs, even when a "gastroprotective" proton pump inhibitor is coadministered) should be taken into consideration, if a coxib will be selected for certain patients with a high risk for GI complications. For such treatment, the lowest effective dose should be used for a limited time. Monitoring of kidney function and blood pressure appears advisable. It is hoped that further controlled studies can better define the therapeutic place of the coxibs.