Safety of the new selective cyclooxygenase type 2 inhibitors rofecoxib and celecoxib in patients with anaphylactoid reactions to nonsteroidal anti-inflammatory drugs

Seven steps to the diagnosis of NSAIDs hypersensitivity: how to apply a new classification in real practice?

Frequent use of non-steroidal anti-inflammatory drugs (NSAIDs) has been paralleled by increasing occurrence of adverse reactions, which vary from mild local skin rashes or gastric irritation to severe, generalized symptoms and even life-threatening anaphylaxis. NSAID-induced hypersensitivity reactions may involve both immunological and non-immunological mechanisms and should be differentiated from type A adverse reactions. Clinical diagnosis and effective management of a hypersensitive patient cannot be achieved without identifying the underlying mechanism. In this review, we discuss the current classification of NSAID-induced adverse reactions and propose a practical diagnostic algorithm that involves 7 steps leading to the determination of the type of NSAID-induced hypersensitivity and allows for proper patient management.

Celecoxib: a review of its use for symptomatic relief in the treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis

Celecoxib (Celebrex®) was the first cyclo-oxygenase (COX)-2 selective inhibitor (coxib) to be introduced into clinical practice. Coxibs were developed to provide anti-inflammatory/analgesic activity similar to that of nonselective NSAIDs, but without their upper gastrointestinal (GI) toxicity, which is thought to result largely from COX-1 inhibition. Celecoxib is indicated in the EU for the symptomatic treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis in adults. This article reviews the clinical efficacy and tolerability of celecoxib in these EU-approved indications, as well as overviewing its pharmacological properties. In randomized controlled trials, celecoxib, at the recommended dosages of 200 or 400 mg/day, was significantly more effective than placebo, at least as effective as or more effective than paracetamol (acetaminophen) and as effective as nonselective NSAIDs and the coxibs etoricoxib and lumiracoxib for the symptomatic treatment of patients with active osteoarthritis, rheumatoid arthritis or ankylosing spondylitis. Celecoxib was generally well tolerated, with mild to moderate upper GI complaints being the most common body system adverse events. In meta-analyses and large safety studies, the incidence of upper GI ulcer complications with recommended dosages of celecoxib was significantly lower than that with nonselective NSAIDs and similar to that with paracetamol and other coxibs. However, concomitant administration of celecoxib with low-dose cardioprotective aspirin often appeared to negate the GI-sparing advantages of celecoxib over NSAIDs. Although one polyp prevention trial noted a dose-related increase in cardiovascular risk with celecoxib 400 and 800 mg/day, other trials have not found any significant difference in cardiovascular risk between celecoxib and placebo or nonselective NSAIDs. Meta-analyses and database-derived analyses are inconsistent regarding cardiovascular risk. At recommended dosages, the risks of increased thrombotic cardiovascular events, or renovascular, hepatic or hypersensitivity reactions with celecoxib would appear to be small and similar to those with NSAIDs. Celecoxib would appear to be a useful option for therapy in patients at high risk for NSAID-induced GI toxicity, or in those responding suboptimally to or intolerant of NSAIDs. To minimize any risk, particularly the cardiovascular risk, celecoxib, like all coxibs and NSAIDs, should be used at the lowest effective dosage for the shortest possible duration after a careful evaluation of the GI, cardiovascular and renal risks of the individual patient.

Safety of parecoxib in asthmatic patients with aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) affects a subset of patients with asthma. Cyclooxygenase 2 inhibitors are a safe alternative in patients with AERD. Parecoxib is the first cyclooxygenase 2 selective drug for parenteral administration, especially useful after surgery thanks to its analgesic power. The aim of the study is to assess the tolerance of parecoxib (Dynastat; Pfizer) given by intramuscular route in patients with AERD.

METHODS

Patients evaluated were referred to the Pneumology and Respiratory Allergy Department of the Hospital Clinic (Barcelona, Spain) for asthma exacerbations precipitated by 2 or more different non-steroidal anti-inflammatory drugs (NSAIDs). AERD was confirmed by a nasal challenge test with aspirin. Patients were challenged with parecoxib, and urine samples were collected to measure the leukotriene E(4) concentration.

RESULTS

Ten patients were challenged with parecoxib. No symptoms were reported with any of the administered doses, and there were no signs of immediate or delayed hypersensitivity. There were no alterations in the forced expiratory volume in 1 s or in acoustic rhinometry measurements. No significant differences between leukotriene E(4) levels were detected.

CONCLUSION

The drug was well tolerated by all patients, with no adverse reactions. This lack of reactions found in our study supports the fact that parecoxib could be a safe alternative in postsurgery analgesia in NSAID-intolerant asthma patients.

Allergic reactions to nonsteroidal anti-inflammatory drugs: is newer better?

In clinical practice, physicians may find it difficult to recognize the differences between allergic and pseudo-allergic reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) and to manage each type of reaction. This paper reviews all the information presently available in order to clarify main problems related to NSAID reactions and to highlight key strategies to handle these reactions.

Tolerance to coxibs in patients with intolerance to non-steroidal anti-inflammatory drugs (NSAIDs): a systematic structured review of the literature

Adverse events triggered by non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drug-related intolerance reactions in medicine; they are possibly related to inhibition of cyclooxygenase-1. Coxibs, preferentially inhibiting cyclooxygenase-2, may therefore represent safe alternatives in patients with NSAID intolerance. We reviewed the literature in a systematic and structured manner to identify and evaluate studies on the tolerance of coxibs in patients with NSAID intolerance. We searched MEDLINE (1966–2006), the COCHRANE LIBRARY (4th Issue 2006) and EMBASE (1966–2006) up to December 9, 2006, and analysed all publications included using a predefined evaluation sheet. Symptoms and severity of adverse events to coxibs were analysed based on all articles comprising such information. Subsequently, the probability for adverse events triggered by coxibs was determined on analyses of double-blind prospective trials only. Among 3,304 patients with NSAID intolerance, 119 adverse events occurred under coxib medication. All adverse events, except two, have been allergic/urticarial in nature; none was lethal, but two were graded as life-threatening (grade 4). The two non-allergic adverse events were described as a grade 1 upper respiratory tract haemorrhage, and a grade 1 gastrointestinal symptom, respectively. In 13 double-blind prospective studies comprising a total of 591 patients with NSAID intolerance, only 13 adverse reactions to coxib provocations were observed. The triggering coxibs were rofecoxib (2/286), celecoxib (6/208), etoricoxib (4/56), and valdecoxib (1/41). This review documents the good tolerability of coxibs in patients with NSAID intolerance, for whom access to this class of drugs for short-term treatment of pain and inflammation is advantageous.

Drug-induced urticarias

Drugs may cause urticaria by different mechanisms. The most well-known mechanism is the allergic reaction mediated by immunoglobulin (Ig)E antibodies, which induce acute generalized urticaria. Allergic reactions to beta-lactams are the most common cause of adverse drug reaction mediated by IgE antibodies. However, IgE antibodies are not always necessary to activate the release of mediators from mast cells and induce acute urticarias. Some drugs, such as opiates or codeine, act directly on mast cells, and others, such as aspirin and nonsteroidal anti-inflammatories, induce an exacerbation of chronic urticaria by a pharmacological mechanism involving the arachidonic acid metabolism. Additionally, angioedema is a wellknown complication of angiotensin-converting enzyme inhibitors by its action on bradykinin, which is a potent vasodilatator agent. Topical drugs, such as antibiotics, disinfectants, or anesthetics, may cause urticaria, which sometimes progresses to generalized urticaria and, more rarely, to anaphylactoid reactions.

The safety of rofecoxib

Like all COX-2 inhibitors, rofecoxib has been developed based on the hypothesis that at comparable therapeutic efficacy, it would have a better safety and tolerability profile than conventional NSAIDs. The Vioxx GI Outcomes Research trial has demonstrated that rofecoxib is indeed safer for the gastrointestinal tract than NSAIDs. However, this study has also raised questions regarding the cardiovascular safety of rofecoxib. Thereafter, several epidemiological and case-control studies have reinforced the association between rofecoxib and a higher risk of cardiovascular events. However, at this time, no prospective controlled study is available to conclude definitively on this issue. Several pathogenic mechanisms are evoked to explain why rofecoxib increases the cardiovascular risk. These include the development of a prothrombotic state, a sodium retention and an increase in systemic blood pressure. Recently, new evidence have become available indicating that rofecoxib indeed increases the number of thrombo-embolic events. These data have resulted in the complete withdrawal of rofecoxib from the market. Was it scientifically reasonable to withdraw rofecoxib rather than to adapt its label? Is the safety profile of rofecoxib really much worse than that of aspirin or other traditional NSAIDs? The main consequence of this withdrawal is a considerable threat on the entire class of selective COX-2 inhibitors without a clear evaluation of the balance between the risks and benefits of these compounds.

Celecoxib tolerability in patients with hypersensitivity (mainly cutaneous reactions) to nonsteroidal anti-inflammatory drugs

BACKGROUND

Adverse reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly observed in clinical practice, particularly among patients with chronic urticaria or asthma. The identification of a safe and reliable alternative is a frequent problem for both general practitioners and allergists.

METHODS

We assessed 120 patients (83 women and 37 men) who had experienced adverse reactions to one or more NSAIDs; 64 (53.3%) of them had reacted to only one NSAID (single reactors) and 56 (46.7%) to multiple NSAIDs (multiple reactors). Among our subjects, 76.7% reported cutaneous reactions, 8.3% respiratory symptoms, 10.8% both cutaneous and respiratory symptoms, and 4.2% anaphylaxis. All patients were subjected to a single-blind, placebo-controlled oral challenge with two different doses of celecoxib (50 + 150 mg 1 h later = cumulative dose of 200 mg).

RESULTS

None of the patients reacted to the placebo and only one (0.8%) suffered a reaction (urticaria) after the second dose of celecoxib.

CONCLUSIONS

Celecoxib showed a 98.9% rate of tolerability in the 92 patients with exclusively cutaneous reactions and was well tolerated by all 28 subjects with NSAID-related respiratory or anaphylactic symptoms.