The aspirin disease

Aspirin sensitivity and chronic rhinosinusitis with polyps: a fatal combination

Aspirin-exacerbated respiratory disease (AERD) refers to aspirin sensitivity, chronic rhinosinusitis (CRS), nasal polyposis, asthma, eosinophil inflammation in the upper and lower airways, urticaria, angioedema, and anaphylaxis following the ingestion of NSAIDs. Epidemiologic and pathophysiological links between these diseases are established. The precise pathogenesis remains less defined, even though there is some progress in the understanding of several molecular mechanisms. Nevertheless, these combinations of diseases in patients classified by AERD constitute a fatal combination and may be difficult to treat with standard medical and surgical interventions. This paper reviews in brief the epidemiology, clinical features, diagnosis, molecular pathogenesis, and specific therapies of patients classified by AERD and postulates future attempts to gain new insights into this disease.

The prevalence of aspirin hypersensitivity in patients with nasal polyposis and contributing factors

BACKGROUND

Aspirin (acetylsalicylic acid [ASA]) hypersensitivity is frequent in patients with nasal polyps (NPs) and is called aspirin exacerbated respiratory disease, previously known as Samter's syndrome. However, studies evaluating the prevalence of ASA hypersensitivity in patients with NPs using the oral aspirin provocation test (APT) are quite limited. This study was designed to determine the prevalence of ASA hypersensitivity and factors associated with ASA hypersensitivity in patients with NPs.

METHODS

Sixty-eight patients with NPs with or without asthma were recruited. Extension of NPs was evaluated by endoscopic examination/paranasal CT. A 2-day, single-blind placebo-controlled APT was used to detect ASA hypersensitivity.

RESULTS

APT was performed in 53 (21 women/ 32 men) patients (mean age, 39.34 ± 1.76 years). APT resulted positive in 12 patients (22.6%) of whom 3 (25%) had no history of ASA hypersensitivity. Of the positive APTs, three were isolated rhinitis and nine had classic responses. APT was negative in 41 patients (77.4%) although three (7.3%) had a history of ASA hypersensitivity. History of ASA hypersensitivity and prolonged duration of NPs were associated with positive APT (p < 0.05). Advanced NP with multiple operations was also correlated with APT positivity but was not statistically significant. Presence of asthma was associated with age, female gender, NP duration, and ASA hypersensitivity history (p < 0.05), but not with smoking, atopy, NP extension, and positive APT.

CONCLUSION

ASA hypersensitivity is quite common in patients with NP. Patients with extensive and long-term NP with multiple polyp operations require evaluation for the presence of ASA hypersensitivity in terms of chronic management and future risks of the disease.

The economic consequences of non-evidence-based clopidogrel use

BACKGROUND

Clinical trials have helped clarify the efficacy of clopidogrel for the treatment and prevention of vascular disease. Costs for its use exceeded $5.9 billion in 2005, making it the second greatest source of drug expenditure in the world. However, little is known about the appropriateness of that use. Overuse of clopidogrel could have important implications for health care quality and drug expenditures.

METHODS

We conducted a retrospective cohort study linking all filled prescriptions to all clinical encounter data for Medicare beneficiaries enrolled in a large state-wide pharmacy assistance program. We identified all patients newly prescribed clopidogrel during a recent 2-year period and determined the proportion who had indications for clopidogrel, the mean number of tablets filled by patients with and without apparent indications in the year after starting therapy, and the costs associated with the observed patterns of clopidogrel use.

RESULTS

We identified 4977 patients who were newly prescribed clopidogrel. Of these patients, only 47% had > or = 1 documented indications for clopidogrel according to clinical trial findings. Using looser criteria, the number of patients with appropriate indications was 56%. During the first year of therapy, 43% ($2.05 million) of total clopidogrel expenditures for the patients studied was spent on patients without an indication that this agent was required, using the extended criteria for evidence-based use.

CONCLUSIONS

More than 40% of the clopidogrel used in this population appears to have been prescribed to patients for whom the drug had no documented advantage over aspirin or no antiplatelet therapy. If the same proportion applies nationally, in 2005, it would represent almost $1.5 billion of potentially unnecessary health care expenditure.

Childhood onset analgesic intolerance: a marker for bronchial asthma in adulthood?

Analgesic intolerance (AI) which is classically known as a disease of the middle-aged adults, not uncommonly starts in childhood. In this study we sought to identify the characteristics of childhood onset AI and evaluated its association with the development of asthma. Among 729 analgesic intolerant patients followed in our institution between January 1991 and July 2004, 50 (16 male, 34 female, 6.8% of the total AI population) had history of AI starting before the age of 18. The prevalence of asthma was 24% in childhood and increased to 40% during adulthood. Atopy was more common in patients with bronchial asthma (p<0.05). The mean (+/-SD) age of onset for asthma (18.6+/-9.7years) was significantly greater than the onset of both rhinitis and AI (13.0+/-6.5 and 13.2+/-4.0 years, respectively). This finding is different than the chronology of events reported in the literature for adult onset AI patients, in which rhinitis and asthma usually precede the development of AI. The presence of such a difference in the sequence of disease patterns may be a clue for the pathophysiologic differences underlying childhood and adult onset AI. The role of childhood onset AI as a risk factor for developing for asthma in adulthood should be further assessed in prospective patient cohorts.

Salicylate intolerance: pathophysiology, clinical spectrum, diagnosis and treatment

INTRODUCTION

Acetylic salicylic acid (aspirin) intolerance relates to altered generation and metabolism of arachidonic acid and eicosanoids, and prostaglandins and leukotrienes ingestion of salicylates or COX-inhibitors.

METHODS

Selective review of literature in PubMed and the Cochrane Library.

RESULTS

Rhinitis, asthma and nasal polyposis are typical presentations, but urticaria and gut inflammation are also described. The mechanism involves a specific reaction to COX inhibitor substances in analgesics, cosmetics or plants resulting in an abnormal pattern of eicosanoids (prostaglandins and leucotrienes). The diagnosis is based on symptoms occurring immediately following ingestion of these substances or on refractory polyp formation. Blood tests may be helpful in unclear cases. Avoidance of triggering agents is helpful. Corticosteroids are the mainstay of pharmacological treatment. Biological, desensitization treatment involving the administration of increasing amounts of acetylic salicylic acid may also be used.

DISCUSSION

Asthma, rhinitis and nasal polyps, as well as chronic gastrointestinal irritation and urticaria following acetylic salicylic acid ingestion may suggest intolerance.

Management options for patients with aspirin and nonsteroidal antiinflammatory drug sensitivity

OBJECTIVE

To evaluate and provide management strategies for patients with aspirin or nonselective nonsteroidal antiinflammatory drug (NSAID) sensitivity.

DATA SOURCES

Literature retrieval was accessed through MEDLINE (1966-March 2007) using the terms acetaminophen, aspirin, antiinflammatory agents nonsteroidal, urticaria, angioedema, asthma, leukotriene antagonists, desensitization, and tacrolimus. Article references retrieved were hand-searched for other relevant articles.

STUDY SELECTION AND DATA EXTRACTION

All studies published in English were evaluated. Studies, review articles, and commentaries on aspirin-induced asthma and aspirin- or NSAID-induced urticaria/angioedema were included in the review.

DATA SYNTHESIS

Aspirin sensitivity is most often manifested as respiratory reactions (eg, bronchospasm, profuse rhinorrhea, conjunctival injection) or urticaria/angioedema. The primary mechanism is believed to be inhibition of the cyclooxygenase 1 (COX-1) enzyme; as such, patients with aspirin sensitivity often display cross-reactions to nonselective NSAIDs that inhibit the COX-1 enzyme. Management strategies include avoidance of aspirin and cross-reacting nonselective NSAIDs. However, desensitization to aspirin is a viable option for patients with aspirin-induced respiratory reactions, especially for those who require aspirin for thromboembolic prophylaxis. Aspirin desensitization is maintained indefinitely with a daily aspirin dose. There is limited evidence of the use of leukotriene modifiers in preventing aspirin-induced asthma. COX-2 selective NSAIDs, especially in patients with aspirin-induced asthma, have not been found to cross-react. However, approximately 4% of patients with a history of aspirin-induced skin reactions may experience a cutaneous reaction following a challenge to a COX-2 selective NSAID. Since acetaminophen is a weak inhibitor of the COX-1 enzyme, patients with aspirin-induced asthma should not take more than 1000 mg of acetaminophen in a single dose.

CONCLUSIONS

Management of patients with aspirin/NSAID sensitivity includes avoidance of aspirin/nonselective NSAIDs, use of COX-2 selective NSAIDs, acetaminophen in doses less than 1000 mg, and desensitization. The role of leukotriene modifiers requires further study before they can be recommended for patients.

General anesthesia and postoperative pain management in analgesic intolerant patients with/without asthma: is it safe?

BACKGROUND

Analgesic intolerance (AI) appears in approximately 1 % of the general population. The triad of bronchial asthma, nasal polyposis, and analgesic intolerance is called analgesic-induced asthma (AIA). These patients are frequently referred to adult allergy clinics for preoperative evaluation for possible analgesic cross reactivity and intolerance to anesthetic agents.

OBJECTIVE

To determine allergic problems related to anesthesia and postoperative pain management in AI patients with and without asthma.

METHODS

The medical records of 45 patients who had been diagnosed with AI between January 1991 and December 2002 in the adult allergy unit and who underwent surgery in the same hospital in the last 4 years were retrospectively analyzed.

RESULTS

The mean age of the patients was 44.4 13.4 years and 30 (66.6 %) were female. Thirty-six (80 %) had AIA, 34 (75.6 %) had persistent allergic rhinitis and 21 (46.7 %) had nasal polyps. Fifty-one surgical procedures were performed in 45 patients, in whom ear, nose and throat surgery was the main procedure (64.7 %). Anesthesia was induced with propofol, fentanyl, and vecuronium and was maintained by sevoflurane or isoflurane. Fentanyl was used for early postoperative pain relief. No complications appeared in relation to anesthesia or early pain management except in a 44-year-old AIA woman who had a reaction in the postoperative period after receiving an inappropriate analgesic.

CONCLUSIONS

None of the patients had anesthesia-related allergic problems. Atropine and diazepam in the premedication, propofol and fentanyl during induction, muscle relaxation facilitation by vecuronium, and sevoflurane or isoflurane for maintenance seem to be a safe general anesthetic choice for analgesic intolerant patients with and without asthma.

Anaesthesia in aspirin-induced asthma

The triad of bronchial asthma, nasal polyposis, and intolerance to aspirin and aspirin-like chemicals are designated aspirin-induced asthma (AIA) or Samter's syndrome. The exact mechanism of the disease is unknown but it is thought to be a disorder of arachidonic acid metabolism. These patients are frequently referred to allergy clinics for preoperative evaluation for possible anesthetic agent sensitivity, requiring anesthesia for nasal polypectomy or several other reasons. Anesthetists must be aware of their pulmonary dysfunction, because the anesthetic management of asthma requires a specific approach. Marked cross-sensitivity with NSAIDs, which may also precipitate severe bronchospasm and adverse reactions, is the main problem faced by anesthetists in postoperative pain management. This article discusses the relationship between AIA and anesthesia. We also present our experience with 47 patients diagnosed with AIA between 1991 and 2003 in the department of chest diseases and adult allergy unit who underwent surgery requiring general anesthesia. In conclusion, preoperative evaluation of these patients and collaboration between the allergists and anesthesiologists is essential to prevent preoperative, perioperative and postoperative complications.

Aspirin intolerance and nasal polyposis

Chronic rhinosinusitis with nasal polyposis usually develops in aspirin-sensitive patients with asthma Arachidonic acid metabolism appears to be abnormal in the nasal polyps of aspirin-sensitive patients with asthma. These abnormalities an characterized by a low production of prostaglandin E2 (PGE2) and a high release of cysteinyl leukotrienes. Moreover, cyclooxygenase-2 is markedly downregulated in polyps from aspirin-sensitive patients with asthma. This abnormality may explain the low production of PGE2 in nasal polyps and may account for the increased susceptibility to the inhibitory effects of aspirin. Nasal instillation or ingestion of aspirin induces a nasal reaction in most aspirin-sensitive patients with asthma. This reaction is accompanied by the influx of eosinophils and a concomitant increase in cysteinyl leukotrienes, tryptase, and eosinophil cationic protein release. The aspirin nasal challenge is a very safe test with a moderate sensibility and high specificity that can be used in the diagnosis of aspirin intolerance. The similarities in the reaction between the nose and airways in aspirin-sensitive patients provide compelling evidence for common pathogenic mechanisms for nasal polyps, chronic rhinosinusitis, and bronchial asthma.

The use of analgesics in patients with asthma

Aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAIDs) cause deterioration in respiratory function in approximately 10% of adults with asthma and a smaller proportion of children with asthma. We propose evidence-based guidelines for the safe use of NSAIDs in individuals with asthma following systematic review of data from the last 10 years relevant to the use of these drugs in such patients. We would currently recommend that patients with asthma who are known to be intolerant of NSAIDs or who exhibit any of the high risk clinical features for intolerance to these drugs (severe asthma, nasal polyps or chronic rhinosinusitis) should use NSAIDs only under close medical supervision. In those with high risk features formal aspirin provocation testing would be recommended prior to the therapeutic use of NSAIDs. Those individuals with asthma who regularly use NSAIDs can continue to do so but should be warned that intolerance to NSAIDs can develop late in life. Lack of relevant experimental evidence precludes the production of evidence-based guidelines for the group of patients with asthma who do not exhibit high risk clinical features and who have never before used NSAIDs. We would currently recommend that this group be treated as potentially intolerant to NSAIDs and use of these drugs can only be recommended under medical supervision but note that further studies and clinical experience could be expected to relax this restriction for many patients. Recent data have suggested that frequent use of paracetamol (acetaminophen) may contribute to a deterioration of respiratory function in asthma. A small proportion of patients with asthma who are NSAID-intolerant experience short-lived deterioration in respiratory function with the use of high doses of paracetamol but this is uncommon and has not been implicated in life-threatening reactions. Routine warnings about paracetamol use in asthma are, therefore, not warranted. Medical personnel, however, should be aware of the potential for worsening of symptoms in some individuals with asthma using paracetamol and institute formal investigation or withdrawal of the drug if they suspect such a reaction.