Safety profile of rofecoxib as used in general practice in England: results of a prescription-event monitoring study

Information about ADRs explored by pharmacovigilance approaches: a qualitative review of studies on antibiotics, SSRIs and NSAIDs

Background

Despite surveillance efforts, unexpected and serious adverse drug reactions (ADRs) repeatedly occur after marketing. The aim of this article is to analyse ADRs reported by available ADR signal detection approaches and to explore which information about new and unexpected ADRs these approaches have detected.

Methods

We selected three therapeutic cases for the review: antibiotics for systemic use, non-steroidal anti-inflammatory medicines (NSAID) and selective serotonin re-uptake inhibitors (SSRI). These groups are widely used and represent different therapeutic classes of medicines. The ADR studies were identified through literature search in Medline and Embase. The search was conducted in July 2007. For each therapeutic case, we analysed the time of publication, the strengths of the evidence of safety in the different approaches, reported ADRs and whether the studies have produced new information about ADRs compared to the information available at the time of marketing.

Results

79 studies were eligible for inclusion in the analysis: 23 antibiotics studies, 35 NSAID studies, 20 SSRI studies. Studies were mainly published from the end of the 1990s and onwards. Although the drugs were launched in different decades, both analytical and observational approaches to ADR studies were similar for all three therapeutic cases: antibiotics, NSAIDs and SSRIs. The studies primarily dealt with analyses of ADRs of the type A and B and to a lesser extent C and D, cf. Rawlins' classification system. The therapeutic cases provided similar results with regard to detecting information about new ADRs despite different time periods and organs attacked. Approaches ranging higher in the evidence hierarchy provided information about risks of already known or expected ADRs, while information about new and previously unknown ADRs was only detected by case reports, the lowest ranking approach in the evidence hierarchy.

Conclusion

Although the medicines were launched in different decades, approaches to the ADR studies were similar for all three therapeutic cases: antibiotics, NSAIDs and SSRIs. Both descriptive and analytical designs were applied. Despite the fact that analytical studies rank higher in the evidence hierarchy, only the lower ranking descriptive case reports/spontaneous reports provided information about new and previously undetected ADRs. This review underscores the importance of systems for spontaneous reporting of ADRs. Therefore, spontaneous reporting should be encouraged further and the information in ADR databases should continuously be subjected to systematic analysis.

Co-administration of rofecoxib and tramadol results in additive or sub-additive interaction during arthritic nociception in rat

Over the decades, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are the most commonly used analgesics in the management of acute and chronic pain. In order to assess a possible antinociceptive interactions, the antinociceptive effects of rofecoxib p.o., a preferential inhibitor of cyclooxygenase-2, and tramadol-hydrochloride p.o., an atypical opioid analgesic, administered either separately or in combination, were determined using a rat model of arthritic pain. The data were interpreted using the surface of synergistic interaction (SSI) analysis and an isobolographic analysis to establish the nature of the interaction. The SSI was calculated from the total antinociceptive effect produced by the combination after subtraction of the antinociceptive effect produced by each individual drug. Female rats received orally rofecoxib alone (1.0, 1.8, 3.2, 5.6, 10.0, 17.8, 31.6 and 56.2 mg/kg), tramadol alone (1.8, 3.2, 5.6, 10.0, 17.8, 31.6 and 56.2 mg/kg) or 12 different combinations of rofecoxib plus tramadol. Five combinations exhibited various degrees of sub-additive (i.e. less than the sum of the effects produced by the each drug alone) antinociceptive effects (3.2 mg/kg tramadol with 7.8 mg/kg rofecoxib; 5.6 mg/kg tramadol with either 10.0 or 17.8 mg/kg rofecoxib; 10.0 mg/kg tramadol with either 10.0 or 17.8 mg/kg rofecoxib), whereas the other 7 combinations showed additive antinociceptive effects (i.e. the sum of the effects produced by each agent alone). Three combination of rofecoxib+tramadol (10.0+5.6, 10.0+10.0, and 17.8+5.6 mg/kg respectively) presented high sub-additive interactions (P<0.002: Q=9.5). The combination rofecoxib (17.8 mg/kg)+tramadol (10.0 mg/kg) caused gastric injuries less severe than those observed with indomethacin, but more severe than those obtained with rofecoxib or tramadol in single administration. The antinociceptive interaction of rofecoxib and tramadol suggests that combinations with these drugs may have no clinical utility in pain therapy.

Association of selective and conventional nonsteroidal antiinflammatory drugs with acute renal failure: A population-based, nested case-control analysis

Conventional nonsteroidal antiinflammatory drugs (NSAIDs) are associated with acute renal failure, but cyclooxygenase-2 inhibitors have not been comparatively evaluated. The authors conducted a nested case-control study to assess the association between exposure to NSAIDs, including cyclooxygenase-2 inhibitors, and hospitalization for acute renal failure. They identified 121,722 new NSAID users older than age 65 years from the administrative health care databases of Quebec, Canada, in 1999-2002. Data for 4,228 cases and 84,540 controls matched on age and follow-up time were analyzed by using conditional logistic regression, adjusted for sex, age, health status, health care utilization measures, exposure to contrast agents, and nephrotoxic medications. The risk of acute renal failure for all NSAIDs combined was highest within 30 days of treatment initiation (adjusted rate ratio (RR) = 2.05, 95% confidence interval (CI): 1.61, 2.60) and receded thereafter. The association with acute renal failure within 30 days of therapy initiation was comparable for rofecoxib (RR = 2.31, 95% CI: 1.73, 3.08), naproxen (RR = 2.42, 95% CI: 1.52, 3.85), and nonselective, non-naproxen NSAIDs (RR = 2.30, 95% CI: 1.60, 3.32) but was borderline lower for celecoxib (RR =1.54, 95% CI: 1.14, 2.09; test for interaction comparing celecoxib with rofecoxib, p = 0.057). There was a significant association for both selective and nonselective NSAIDs with acute renal failure, but confirmatory studies are required.

Risk of hospitalization for angio-oedema among users of newer COX-2 selective inhibitors and other nonsteroidal anti-inflammatory drugs

AIM

To examine the risk of angio-oedema among users of the newer cyclooxygenase (COX)-2 selective inhibitors celecoxib and rofecoxib and other non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) in a population-based case-control study.

METHODS

Cases of angio-oedema were identified from hospital discharge registries from three Danish counties between 1 January 2000 and 31 December 2003 (n = 377) and 10 matched population controls per case were selected from the Civil Registration System (n = 3747). Data on newer COX-2 selective inhibitor and other NSAID use (current and former) were obtained from prescription databases. Data on potential confounding factors were also collected. Conditional logistic regression was used to compute relative risks for angio-oedema according to drug exposure.

RESULTS

The crude relative risks for the newer COX-2 selective inhibitors were higher than those for other NSAIDs. After adjustment for confounding, the relative risk for current use of newer COX-2 selective inhibitors was 0.96 [95% confidence interval (CI) 0.46, 2.03], whereas the risk for other NSAIDs was 1.77 (95% CI 1.23, 2.58).

CONCLUSION

Our data support the hypothesis that newer COX-2 selective inhibitors are safe in relation to angio-oedema. However, given other current health concerns related to these drugs, their use should continue to be carefully monitored.

Comparison of reporting of Stevens-Johnson syndrome and toxic epidermal necrolysis in association with selective COX-2 inhibitors

BACKGROUND

Stevens-Johnson syndrome and toxic epidermal necrolysis are closely related severe acute life-threatening, drug-induced skin disorders. The US FDA Adverse Events Reporting System (AERS) has received reports of Stevens-Johnson syndrome and toxic epidermal necrolysis associated with the use of the recently introduced selective cyclo-oxygenase (COX)-2 inhibitor NSAIDs, two of which are also sulfonamides.

OBJECTIVE

The objective of this study is to review cases of Stevens-Johnson syndrome and toxic epidermal necrolysis reported to the FDA associated with the use of the selective COX-2 inhibitor NSAIDs celecoxib, rofecoxib and valdecoxib, and to compare reporting rates of the two conditions associated with these drugs to each other, meloxicam (an oxicam NSAID that came on the US market at a similar time) and the background incidence rate.

METHODS

We reviewed all US cases of Stevens-Johnson syndrome and toxic epidermal necrolysis reported to the FDA AERS database associated with the use of celecoxib, rofecoxib, valdecoxib and meloxicam since these agents were first marketed. We utilised AERS and drug use data to calculate reporting rates for each drug after the first 2 years of marketing. We obtained the background rate from the medical literature.

RESULTS

Up to the end of March 2004, there were 63 cases of Stevens-Johnson syndrome/toxic epidermal necrolysis reported with valdecoxib use, 43 with celecoxib, 17 with rofecoxib (the non-sulfonamide coxib) and none for meloxicam. In the first 2 years of marketing the reporting rate for Stevens-Johnson syndrome/toxic epidermal necrolysis with valdecoxib was 49 cases per million person-years of use, 6 cases per million person-years for celecoxib and 3 cases per million person-years for rofecoxib. The reporting rates for the sulfonamide coxibs were substantially higher than the background rate of 1.9 cases per million population per year, with the valdecoxib rate being 8-9 times that of celecoxib and approximately 25 times that of the background rate.

CONCLUSION

There is a strong association between Stevens-Johnson syndrome/toxic epidermal necrolysis and the use of the sulfonamide COX-2 inhibitors, particularly valdecoxib. Physicians should be aware of the possibility of this serious life-threatening event when prescribing these drugs and advise patients to discontinue use at the earliest possible sign or symptom.

A comparison of reported gastrointestinal and thromboembolic events between rofecoxib and celecoxib using observational data

BACKGROUND AND OBJECTIVES

Rofecoxib, a selective cyclo-oxygenase (COX)-2 inhibitor, was a widely marketed drug that was used for relief of pain and inflammation in arthritic conditions. It was withdrawn from the market worldwide in September 2004 because of an increased risk of cardiovascular events. Celecoxib, which belongs to the same class of drugs, is now under scrutiny for the risk of similar events. The objective of our study was to compare the incidence of gastrointestinal (GI) [symptomatic and complicated upper GI] events and thromboembolic (cardiovascular, cerebrovascular and peripheral venous) events reported for patients prescribed rofecoxib or celecoxib in primary care.

METHODS

A retrospective analysis of selected events was conducted using data collected from previously conducted prescription-event monitoring (PEM) studies for rofecoxib and celecoxib. PEM is an observational cohort technique. Exposure data were derived from dispensed prescriptions for rofecoxib (July-November 1999) and celecoxib (May-December 2000) that were written by primary care general practitioners in England. Outcome data were clinical events and information on potential risk factors reported on simple questionnaires (posted to prescribers approximately 9 months after the date of the first prescription). Incidence rates of the first event during treatment within each thromboembolic and GI group were calculated during the 270 days after the patient started receiving either of the drugs; crude and adjusted rate ratios (RR) were calculated for rofecoxib compared with celecoxib using Poisson regression modelling.

RESULTS

The rofecoxib and celecoxib PEM cohorts contained 15 268 and 17 458 patients, respectively. For the GI event groups, the adjusted RRs for rofecoxib compared with celecoxib were: 1.21 (95% CI 1.09, 1.36) for symptomatic upper GI events and 1.60 (95% CI 0.95, 2.70) for complicated upper GI conditions. For the thromboembolic event groups, the adjusted RRs were: 1.04 (95% CI 0.50, 2.17) for cardiovascular thromboembolic events; 1.43 (95% CI 0.86, 2.38) for cerebrovascular thromboembolic events; and 0.36 (95% CI 0.01, 1.34) for peripheral venous thromboembolic events.

CONCLUSIONS

This study was a retrospective comparison of PEM studies conducted for rofecoxib and celecoxib. For symptomatic upper GI events, a 21% increase in the relative rate was found for rofecoxib users compared with celecoxib users after adjusting for identified risk factors. For complicated upper GI events, no statistically significant difference in the incidence was observed between rofecoxib and celecoxib users after adjusting for identified risk factors. For the three thromboembolic event groups, no evidence of a statistically significant difference between rofecoxib and celecoxib users was found after adjusting for identified risk factors. This study contributes to the understanding of the association between COX-2 inhibitors and thromboembolic events. However, it should be borne in mind that we had information on only a limited number of confounding variables for thromboembolic events. Further research is required to fully understand the risks and benefits of using celecoxib and other COX-2 inhibitors. Meanwhile, doctors should be cautious when prescribing these products, particularly to patients with risk factors for developing thromboembolic events.

The trade-off between cardiovascular and gastrointestinal effects of rofecoxib

BACKGROUND

The cyclooxygenase-2 (COX-2) inhibitor rofecoxib was registered in 1999. By 2000, the first reports were published indicating that the agent was possibly associated with an increased risk of myocardial infarction. Since then a surge of data supporting this association has become available. To interpret these data it is essential to ascertain the cardiovascular risk profile of users of rofecoxib relative to other non-steroidal anti-inflammatory drug (NSAID) recipients.

OBJECTIVE

To assess differences in cardiovascular risk between starters of rofecoxib versus starters of any other NSAID.

SETTING

Data sampled from a representative research network of Dutch general practitioners (GPs) in 2001.

DESIGN

New users (starters) of rofecoxib were compared to starters of any other NSAID, unmatched and matched on age, gender, and indication nested in the cohort of the second Dutch National Survey of General Practice.

RESULTS

A total of 40.4% of patients starting on rofecoxib had cardiovascular co-morbidity. Patients starting on rofecoxib were twice more likely to have a history of gastrointestinal (GI) morbidity, compared to patients starting on other NSAIDs (OR(adj) = 2.09; 95%CI = 1.65-2.66). These patients were also more likely to have cardiovascular co-morbidity (OR = 1.90; 95%CI = 1.60-2.24) compared to recipients of rofecoxib with no GI co-morbidity. Cardiovascular morbidity was present at the time of rofecoxib exposure in over 61% of carriers of a composite risk profile including age 60 years or older, GI co-morbidity and diagnosis of rheumatoid arthritis and osteoarthritis.

CONCLUSIONS

In general, a typical recipient of an NSAID is aged and carrier of a serious cardiovascular risk profile. Selective prescribing of rofecoxib to provide claimed gastroprotection, indirectly and unintentionally resulted in prescribing rofecoxib in a population with high frequencies of cardiovascular morbidities.

Upper gastrointestinal adverse drug reactions and cyclo-oxygenase-2 inhibitors (celecoxib and rofecoxib): a case/non-case study from the French Pharmacovigilance Database

OBJECTIVE

To evaluate the gastrointestinal safety of cyclo-oxygenase-2 inhibitors under their real conditions of use. DESIGN. Case/non-case study.

SETTING

Adverse drug reactions (ADRs) in adults recorded in the French Pharmacovigilance Database between 25 May 2000 and 31 December 2002.

MATERIALS

Cases were all reports of "serious" oeso-gastro-duodenal ADRs (oeso-gastro-duodenal ulcers, oesophagitis, gastritis, duodenitis). Five non-cases were randomly selected for one case from all other non oeso-gastro-duodenal reports in the database after matching them for age, gender and period of occurrence.

ANALYSIS

Coxib exposure was compared among cases and non-cases, with adjustment for matching factors: French Regional Pharmacovigilance Centres that collected ADRs, reporter health professional's characteristics and exposures to non-selective non-steroidal anti-inflammatory, aspirin, anticoagulant, antiplatelet and gastroprotective drugs.

RESULTS

Included in the study were 505 cases and 2,525 non-cases. A positive association was found between occurrence of oeso-gastro-duodenal ADRs and coxib (adjusted odds ratio 14.9 [95% CI 9.3-23.7]), diclofenac (9.2 [3.8-22.2]), ibuprofen (7.3 [3.2-16.6]) or oxicam (25.3 [11.9-53.6]) use.

CONCLUSION

Despite the compulsory limits of the case/non-case methodology, the present study shows that coxibs did induce "serious" gastrointestinal ADRs in real clinical practice. These results underline the need for pharmacoepidemiological studies under real conditions of use in order to verify (or not) the conclusions of clinical trials.

Lessons from the withdrawal of rofecoxib

Patients would be safer if drug companies disclosed adverse events before licensing

Do some inhibitors of COX-2 increase the risk of thromboembolic events?: Linking pharmacology with pharmacoepidemiology

Inhibitors of the cyclo-oxygenase (COX)-2 isoenzyme were developed with the expectation that their use would be accompanied by a reduction in adverse reactions thought to be mediated through COX-1 compared with conventional nonselective NSAIDs. However, the results of some clinical studies and other evidence have led to the hypothesis that use of COX-2 inhibitors may contribute to an increased risk of adverse thromboembolic (TE) events. In this review, we have evaluated the evidence from small-scale in vitro and in vivo pharmacological studies, clinical trials and large-scale pharmacoepidemiological studies and commented on the relationship between the pharmacological characteristics related to thromboembolic events and the clinical effects in large-scale clinical trials and pharmacoepidemiological studies. Overall, the pharmacological evidence suggests that a prothrombotic effect of COX-2 selective inhibitors is plausible. To date, despite the results from the Vioxx Gastrointestinal Outcome Research (VIGOR) study from which the clinical concern regarding cardiovascular TE risk arose, the published data from other randomised controlled trials (RCTs), retrospective observational studies and spontaneous reporting schemes provide a conflicting body of evidence on the TE risk with COX-2 inhibitors. Concerns that COX-2 inhibitors may be associated with prothrombotic effects remain and these need to be addressed in large scale, RCTs designed specifically to investigate the possibility of an excess of adverse cardiovascular outcomes in users of some or all selective COX-2 inhibitors, both with and without concomitant low-dose aspirin (acetylsalicylic acid). Consideration must also be given to other pathophysiological mechanisms for potential cardiovascular risk linked with inhibition of COX-2. In view of the evidence reviewed, it is recommended that selective COX-2 inhibitors should be prescribed with caution, only in patients with conditions for which these drugs have proven efficacy and with careful monitoring of outcomes and adverse events. This is particularly important in the elderly, in patients with cardiovascular/renal disease and in patients with other risk factors that might predispose them to adverse events.

Safety profile of celecoxib as used in general practice in England: results of a prescription-event monitoring study

AIMS

A post-marketing surveillance study using the technique of Prescription Event Monitoring was undertaken to monitor the safety of celecoxib, a cyclo-oxygenase (COX)-2 inhibitor, as prescribed in primary care in England.

METHODS

Patients were identified from dispensed British National Health Service prescription data supplied in confidence by the Prescription Pricing Authority for celecoxib between May and December 2000. Simple questionnaires were sent to the prescribing general practitioner at least 6 months after the date of the first dispensed prescription for each individual patient. Event incidence densities (IDs) [the number of 1st reports per 1000 patient-months of exposure (pme)] were calculated. ID differences for events reported in month 1 (ID1) and months 2-6 (ID2) were examined for temporal changes in event rate. Information on suspected adverse drug reactions (ADRs), reasons for stopping treatment, outcome of pregnancies and cause of death were also requested. Data were gathered on potential gastrointestinal (GI) risk factors [recent use of other non-steroidal anti-inflammatory drugs (NSAIDs), past history of upper GI disorders and concomitant gastro-irritant agents or anti-ulcer drugs]. Crude IDs per 1000 pme and ID ratios were calculated according to potential risk factors, and age (> or = 65 years, < or = 64 years).

RESULTS

The cohort comprised of 17,458 patients [median age 62 years (IQR 51,73); 68.3% female]. The most common specified indication was osteoarthritis (28.1%, n = 4905). Not effective was the event with the highest ID1 (139.9 per 1000 pme). The clinical events with the highest ID1 were dyspepsia (25.4 per 1000 pme) followed by abdominal pain (10.6). These were also given frequently as reasons for stopping (551 and 174 of 9126 reports). Of 436 events in 325 patients (1.9% of total cohort) that were reported as ADRs, the most frequent were events within the alimentary system (186 reports). Uncommon events reported during treatment (not necessarily as ADRs) included allergy (0.10%, n = 17), anaphylaxis (0.01%, n = 2), angioneurotic oedema (0.02%, n = 3) and bronchospasm (0.05%, n = 9). There were 103 reports of events associated with thromboembolism and 111 reports of serious GI events [90 GI bleeds (upper and lower); 21 peptic ulcers] received during treatment or within 1 month of stopping. A past history of dyspeptic/other upper GI conditions and use of concomitant gastro-protective drugs were each associated with a significantly increased risk of dyspepsia and abdominal pain.

CONCLUSIONS

Frequently reported adverse events were those GI events commonly associated with treatment with other NSAIDS. Stratification by identified risk factors suggested that channelling of high-risk patients is likely. Serious upper and lower GI events, and thromboembolic events did occur during this study, although the incidence was low (< 1%). Doctors should continue to prescribe NSAIDs, including COX-2-specific inhibitors, with caution.

Benefit-risk assessment of rofecoxib in the treatment of osteoarthritis

NSAIDs are widely used to treat pain and inflammation in osteoarthritis. Their use in this indication is generally intermittent and fluctuates with the intensity of the disease. Nonetheless, success of the therapy is frequently limited by injury to the gastrointestinal mucosa and complications such as bleeding, ulceration and perforation. A careful and detailed evaluation of these aspects in regard to the newly introduced NSAIDs is of considerable clinical importance. This review focuses on the NSAID rofecoxib, one of the selective cyclo-oxygenase (COX)-2 inhibitors, which are claimed to be as effective as nonselective NSAIDs with better gastrointestinal tolerability. Indeed, phase II, phase III and epidemiological studies have revealed that the efficacy of rofecoxib is comparable to that of conventional NSAIDs but with lower gastrointestinal toxicity, although this advantage may not be demonstrable in every patient. In patients treated with low-dose aspirin (acetylsalicylic acid) for cardiovascular prophylaxis, celecoxib (another selective COX-2 inhibitor) seems to have no obvious advantages over conventional NSAIDs, and similar conclusions may be applied to rofecoxib. A comparison of NSAID therapy +/- concomitant low-dose aspirin was not a primary outcome in this trial with celecoxib and there is thus a need for further studies which compare the gastrointestinal risk of a selective COX-2 inhibitor plus aspirin versus a conventional NSAID. Recent debate has emerged regarding the cardiovascular safety of rofecoxib. Although there is evidence both for and against higher cardiovascular risk with rofecoxib, a retrospective cohort study recently published suggested that there is no increased risk of acute myocardial infarction in the short-term when compared with non-selective NSAIDs. The renal toxicity of rofecoxib has been thoroughly investigated. Clinical studies revealed renal effects of rofecoxib similar to those of conventional NSAIDs. Since adverse effects increase with the degree of renal impairment, monitoring of renal function should be carried out in patients at risk. Although there are still insufficient data concerning certain important adverse effects of rofecoxib, this drug is becoming an important alternative in the therapy of osteoarthritis, especially in high-risk patients. Clinicians need to weigh up the benefits and risks of rofecoxib on a case-by-base basis.

Identification and evaluation of a possible signal of exacerbation of colitis during rofecoxib treatment, using Prescription-Event Monitoring data

BACKGROUND

Identifying previously unrecognized adverse drug reactions (signals) is an important part of post-marketing surveillance. Automated signal generation now forms part of routine surveillance of spontaneous adverse drug reactions reported to the UK Yellow Card system. The Drug Safety Research Unit (DRSU) provides an additional post-marketing drug surveillance scheme in the UK, using the non-interventional observational cohort technique of Prescription-Event Monitoring (PEM), and systematically collects data on patients who were prescribed selected newly licensed drugs in primary care clinical practice. The introduction of a new computer system in January 2000 enabled the development of an automated signal generation system to compliment the process of identification of possible safety signals in drug data collected using PEM.

AIMS

To use incidence rate ratios (IRRs) as a form of signal generation in the DSRU database, with particular interest in rofecoxib, plus further evaluation of any signal(s) of interest by requesting additional information from the general practioner (GP) of each relevant case.

METHODS

Crude IRRs were calculated for each event term of interest by comparing the incidence rate for each lower term event reported in rofecoxib users with the comparable incidence rate for the whole PEM database (77 drugs of various therapeutic classes) from the total person-exposure time up to 180 days after starting the drug. To investigate a possible class effect, IRRs were also calculated using a second comparator cohort including only those PEM study drugs within the same therapeutic class (non-steroidal anti-inflammatory drugs, NSAIDs) and used for similar indications. Cases arising out of potential signals were followed up for additional information.

RESULTS

A potential signal of 'colitis' was identified when rofecoxib was compared with the rest of the database, IRR 5.8 (95% CI 2.7,11.3; z statistic 5.6), and when the comparator group was changed to include only the other four NSAIDs, IRR 4.3 (95% CI 1.4,14.5; z statistic 2.8). Other possible signals, compared with the rest of the database, included events deemed to be related to the underlying condition, labelled adverse events and events describing effectiveness of treatment. Further evaluation of this signal revealed that there were 11 reports of colitis (two reports for one patient) that occurred while taking rofecoxib and within 180 days of exposure. A causality assessment for these 10 patients did not confirm an association with newly developing colitis, but showed that the events were 'possible' exacerbations of pre-existing colitis during treatment with rofecoxib.

CONCLUSIONS

The use of IRRs for signal generation using PEM data is worthwhile and enables time to be taken into account. Previously unrecognized adverse events require further evaluation to confirm that a possible safety signal exists. In this study, the number of patients reported to have colitis was small but compared with other drugs on the database, the incidence rate was relatively high. Follow-up revealed a possible relationship between exacerbation of pre-existing colitis and treatment with rofecoxib. Hypotheses arising from signal generation require evaluation and cannot be taken as a conclusive evidence for clinical differences in the safety profiles of drugs.

Coxibs, quel réel progrès thérapeutique ? : données pharmacoépidémiologiques récentes

Therapeutic advance is defined by an improvement in effectiveness, safety and/or convenience. In this article, these three criteria were applied to currently marketed coxibs (celecoxib, rofecoxib), using data from clinical trials and pharmacoepidemiological studies. Risk of adverse drug reactions to coxibs, as evaluated by clinical trials, differs from that observed in real medical practice. Rofecoxib and celecoxib exhibit the same profile of adverse drug reactions as the other classical nonsteroidal anti-inflammatory drugs. Coxibs are currently prescribed and too often used outside the studied and approved indications, which clearly increases their cost (already high for society). Currently marketed coxibs do not appear to meet the previously defined criteria for therapeutic advance.

Cyclooxygenase-2 inhibitors: Do they have a role in emergency department prescribing?

Cyclooxygenase-2 selective inhibitors (COXIB or CSI) have been released with a fanfare as efficacious and safer alternatives to traditional non-steroidal anti-inflammatory drugs. They purport to offer equivalent degrees of analgesia and an improved safety profile. COXIB currently available in Australasia are celecoxib (Celebrex), rofecoxib (Vioxx) and etoricoxib (Arcoxia). This review discusses the pharmacology of these agents and reviews recent literature regarding their effectiveness and safety. It endeavours to answer the question 'Should we be using COXIB in emergency departments in Australasia'?

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.