COX-1 sparing drugs in aspirin-sensitive asthma

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.

Safety of triflusal (antiplatelet drug) in patients with aspirin-exacerbated respiratory diseases

BACKGROUND AND AIMS

Aspirin, a cyclo-oxygenase (COX)-1 and COX-2 inhibitor, is the antiplatelet drug of choice to prevent serious vascular events. Adverse reactions to aspirin are frequent particularly among patients with asthma, chronic rhinosinusitis and nasal polyps. COX-1 inhibitors but not COX-2 inhibitors precipitate asthma attacks. Triflusal is a preferential COX-2 inhibitor antiplatelet agent that is as effective as aspirin in the prevention of serious vascular events. The aim of the study was to assess the tolerability of triflusal in patients with aspirin-exacerbated respiratory disease (AERD).

METHODS

We studied 26 asthma patients [11 males, aged 52 (23-75) years] who had suffered asthma episodes triggered by one or more (23% of patients) nonsteroidal anti-inflammatory drugs. Aspirin sensitivity was confirmed by either intranasal or oral aspirin challenge. All subjects underwent a single-blind, placebo-controlled oral challenge with three doses of triflusal separated by 1 week (first cumulative dose = 225 mg; second cumulative dose = 450 mg; third cumulative dose = 900 mg). Cutaneous, respiratory, general symptoms and lung function were monitored for 4 h in the laboratory and for 24 h at home.

RESULTS

No clinical reactions to triflusal were observed. There were no significant changes in lung function measurements.

CONCLUSION

Our study appears to demonstrate that triflusal is a suitable alternative to aspirin as antiplatelet agent to prevent AERD.

Mechanisms of aspirin sensitivity

In some asthma patients, nonsteroidal anti-inflammatory drugs (NSAIDs) induce bronchospasm, rhinorrhea, and nasal obstruction. NSAID-induced reactions appear to be caused by the inhibition of cyclooxygenase-1 (Cox-1); this in turn activates the lipoxygenase pathway, which eventually increases the release of cysteinyl leukotrienes (Cys-LTs) that induces bronchospasm and nasal obstruction. With regard to the metabolism of arachidonic acid (AA) in NSAID-intolerant asthmatic patients, the following changes have been observed: 1) A low production of prostaglandin E2, seemingly due to deficient Cox-2 regulation; 2) an increased expression of leukotriene-C4 synthase; and 3) a reduced production of metabolites (lipoxins) released through the transcellular metabolism of AA. NSAID-intolerant asthmatics have higher basal levels of Cys-LT than NSAID-tolerant asthmatics. Moreover, Cys-LT levels in NSAID-intolerant asthmatics increase remarkably following NSAID provocation testing. There has been no explanation to date that connects all these findings, although an anomaly in the regulation of Cox-2 is probably accountable.

Nuclear factor-kappaB activity is down-regulated in nasal polyps from aspirin-sensitive asthmatics

BACKGROUND

We examined whether a decreased activity of nuclear factor(NF)-kappaB), a transcriptional regulator of cyclooxygenase-2 (COX-2), could account for down-regulation of COX-2 in nasal polyps of aspirin-sensitive asthmatics.

METHODS

Nasal polyps were obtained from 17 aspirin-intolerant asthma/rhinitis patients (AIAR; 7 men, mean age 48 +/- 12 years) and 23 aspirin-tolerant asthma/rhinitis patients (ATAR; 12 men, mean age 65 +/- 11 years). COX-2 mRNA expression was measured using semiquantitative reverse transcriptase competitive polymerase chain reaction (RT-PCR), and the results were expressed as mean +/- standard error of 106 molecules of mRNA/ micro g of total RNA. NF-kappaB binding was measured with 32P-labeled oligonucleotides and electrophoretic mobility shift assay (EMSA), and the results were expressed as a percentage with respect to the mean EMSA obtained in 19 healthy nasal mucosa.

RESULTS

The mean levels of COX-2 mRNA expression (0.25 +/- 0.06) and NF-kappaB activity (89 +/- 13) in nasal polyps from AIAR were significantly lower than in polyps from ATAR (COX-2 = 1.58 +/- 0.50, and NF-kappaB = 143 +/- 12, P < 0.01 and P < 0.05, respectively). Levels of COX-2 mRNA and NF-kappaB activity in polyps from patients on corticosteroid therapy did not differ statistically from those who were not on this therapy before polypectomy.

CONCLUSION

This study shows that the low expression of COX-2 mRNA in nasal polyps from aspirin-sensitive patients is associated with a down-regulation of NF-kappaB activity.

Safety of rofecoxib in subjects with a history of adverse cutaneous reactions to aspirin and/or non-steroidal anti-inflammatory drugs

BACKGROUND

Adverse reactions to non-steroidal anti-inflammatory drugs (NSAID)s are frequent, and the need to identify a safe alternative drug is a common problem in clinical practice.

OBJECTIVE

To assess the tolerability of rofecoxib, a drug that specifically inhibits COX-2, in a group of NSAID-sensitive patients.

METHODS

One-hundred and four subjects (29 males and 75 females, mean age 35.6 +/- 14.1) were enrolled. All subjects had experienced one or more episode characterized by cutaneous symptoms (erythema, and/or urticaria angioedema) following the assumption of NSAIDs; 92 subjects experienced reactions to only one NSAID (single intolerance: SI) and 12 subjects had reactions to multiple NSAIDs (multiple intolerance: MI). Rofecoxib was challenged at the following dosages: 1/4 of 25 mg (6.25 mg), 1/4 of 25 mg, and 1/2 of 25 mg (12.5 mg), at intervals of 1 h if no symptoms had developed with the previous administration, in order to reach a cumulative dose of 25 mg. All subjects underwent two double-blind, placebo-controlled challenges in two consecutive days.

RESULTS

No reactions against placebo were observed. Similarly, no reactions were observed in all subjects both after the first and after the second challenge to rofecoxib.

CONCLUSIONS

The present study demonstrated that rofecoxib does not have cross-reactivity to NSAIDs. Rofecoxib is a safe alternative in subjects with previous adverse cutaneous reaction to NSAIDs.