The effect of indication on hypersensitivity reactions associated with zomepirac sodium and other nonsteroidal antiinflammatory drugs

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

Cyclo-oxygenase selectivity and chemical groups of nonsteroidal anti-inflammatory drugs and the frequency of reporting hypersensitivity reactions: a case/noncase study in VigiBase

To date, no reports of hypersensitivity reactions (HSRs) among nonsteroidal anti-inflammatory drugs (NSAIDs) according to cyclo-oxygenase (COX) selectivity and chemical groups have been published in a single study. The present study assessed the reporting frequency of HSRs for NSAIDs based on their relative inhibitory potency toward COX enzymes and chemical groups, including the presence/absence of a functional sulfonamide group, in strata observed 5 years after market authorization. A case/noncase study was performed among individual case safety reports (ICSRs) with NSAIDs as suspected drugs in VigiBase, the WHO spontaneous reporting database. Cases were ICSRs mentioning angioedema and anaphylactic/anaphylactoid shock conditions, while noncases were ICSRs without HSRs. NSAIDs were categorized into (i) NSAIDs with high COX-2 selectivity (coxibs), (ii) noncoxib NSAIDs with COX-2 preference, (iii) NSAIDs with poor selectivity, or (iv) NSAIDs with unknown selectivity. Chemical groups were defined based on the Anatomical Therapeutic Chemical classification system and the presence/absence of a functional sulfonamide group. Reporting odds ratios (RORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression analysis. We identified 13 229 cases and 106 444 noncases. In the first 5 years after marketing, poor-selectivity NSAIDs and acetic acid derivatives were associated with the highest ROR of HSRs (age- and sex-adjusted ROR 2.12, 95% CI 1.98-2.28; and ROR 2.21, 95% CI 1.83-2.66, respectively) compared with coxibs, and sulfonamide NSAIDs were associated with the highest ROR of HSRs compared with nonsulfonamide NSAIDs (age- and sex-adjusted ROR 1.38, 95% CI 1.29-1.47). After the first 5 years of marketing, most of the RORs returned to approximately 1.

Safety Assessment of Acyl Glucuronides-A Simplified Paradigm

While simple O- (ether-linked) and N-glucuronide drug conjugates generally are unreactive and considered benign from a safety perspective, the acyl glucuronides that derive from metabolism of carboxylic acid-containing xenobiotics can exhibit a degree of chemical reactivity that is dependent upon their molecular structure. As a result, concerns have arisen over the safety of acyl glucuronides as a class, several members of which have been implicated in the toxicity of their respective parent drugs. However, direct evidence in support of these claims remains sparse, and due to frequently encountered species differences in the systemic exposure to acyl glucuronides (both of the parent drug and oxidized derivatives thereof), coupled with their instability in aqueous media and potential to undergo chemical rearrangement (acyl migration), qualification of these conjugates by traditional safety assessment methods can be very challenging. In this Commentary, we discuss alternative (non-acyl glucuronide) mechanisms by which carboxylic acids may cause serious adverse reactions, and propose a novel, practical approach to compare systemic exposure to acyl glucuronide metabolites in humans to that in animal species used in preclinical safety assessment based on relative estimates of the total body burden of these circulating conjugates.

Angioedema in the emergency department: a practical guide to differential diagnosis and management

Background

Angioedema is a common presentation in the emergency department (ED). Airway angioedema can be fatal; therefore, prompt diagnosis and correct treatment are vital.

Objective of the review

Based on the findings of two expert panels attended by international experts in angioedema and emergency medicine, this review aims to provide practical guidance on the diagnosis, differentiation, and management of histamine- and bradykinin-mediated angioedema in the ED.

Review

The most common pathophysiology underlying angioedema is mediated by histamine; however, ED staff must be alert for the less common bradykinin-mediated forms of angioedema. Crucially, bradykinin-mediated angioedema does not respond to the same treatment as histamine-mediated angioedema. Bradykinin-mediated angioedema can result from many causes, including hereditary defects in C1 esterase inhibitor (C1-INH), side effects of angiotensin-converting enzyme inhibitors (ACEis), or acquired deficiency in C1-INH. The increased use of ACEis in recent decades has resulted in more frequent encounters with ACEi-induced angioedema in the ED; however, surveys have shown that many ED staff may not know how to recognize or manage bradykinin-mediated angioedema, and hospitals may not have specific medications or protocols in place.

Conclusion

ED physicians must be aware of the different pathophysiologic pathways that lead to angioedema in order to efficiently and effectively manage these potentially fatal conditions.

Adverse and Hypersensitivity Reactions to Prescription Nonsteroidal Anti-Inflammatory Agents in a Large Health Care System

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used medications in the United States. NSAID use can be limited by adverse drug reactions (ADRs), including hypersensitivity reactions (HSRs).

OBJECTIVE

We aimed to use electronic health record data to determine the incidence and predictors of HSRs to prescription NSAIDs.

METHODS

We performed a retrospective cohort study of all adult outpatients in a large health care system prescribed diclofenac, indomethacin, nabumetone, or piroxicam between January 1, 2004, and September 30, 2012. The primary outcome was an ADR or HSR attributed to the prescribed NSAID within 1 year of prescription, determined from a longitudinal allergy database. We used natural language processing to classify known ADRs as either HSRs or side effects. Multivariable logistic regression models were used to identify independent risk factors for NSAID HSRs.

RESULTS

Of 62,719 patients prescribed NSAIDs, 1,035 (1.7%) had an ADR, of which 189 (18.3%) were HSRs. Multivariable regression analysis identified that patients with prior drug HSR history (odds ratio [OR] 1.8 [95% CI 1.3, 2.5]), female sex (OR 1.8 [95% CI 1.3, 2.4]), autoimmune disease (OR 1.7 [95% CI 1.1, 2.7]), and those prescribed the maximum standing NSAID dose (OR 1.5 [95% CI 1.1, 2.0]) had increased odds of NSAID HSR.

CONCLUSIONS

NSAID therapeutic use can be limited by ADRs; about 1 in 5 NSAID ADRs is an HSR. Both patient and drug factors contribute to HSR risk and are important to guide patient counseling.

Clinical Management of Nonsteroidal Anti-inflammatory Drug Hypersensitivity

Hypersensitivity diseases caused by nonsteroidal anti-inflammatory agents are relatively common in the population. This article summarizes the present understanding on the various allergic and nonallergic clinical pictures produced through hypersensitivity to these drugs using the pathogenic classification of hypersensitivity reactions recently proposed by the Nomenclature Committee of the World Allergy Organization to guide clinicians in the diagnosis and management of patients with these conditions.

Life-Threatening ACE Inhibitor-Induced Angioedema After Eleven Years on Lisinopril

Angiotensin-converting enzyme inhibitors (ACE-Is) are the primary medication class implicated in drug-associated angioedema. Angioedema is most common early in ACE-I therapy, yet episodes can occur late in therapy and have been reported even as late as 10 years after single treatment initiation. We present a case of a 65-year-old African American woman who experienced 2 episodes of angioedema, with the second being life threatening after receiving several concomitant agents known to cause angioedema, most notably lisinopril for 11 years.

Diagnosis and management of angioedema with abdominal involvement: A gastroenterology perspective

Abdominal involvement in angioedema is often a challenge to diagnose. Acute onset abdominal pain is its most common presenting symptom, and misdiagnosis may lead to unnecessary surgical intervention. Familiarity with the types and presentations of angioedema can be invaluable to clinicians as they consider the differential diagnoses of a patient presenting with abdominal pain. Detailed personal and family histories, careful physical examination of the patient, combined with knowledge of angioedema types, can help clinicians perform their diagnostic evaluation. An accurate diagnosis is essential in order to provide appropriate treatment to patients with angioedema. Depending upon the diagnosis, treatment may be the avoidance of provoking factors (such as allergens or medications), inhibiting histamine-provoked reactions, or treating C1 esterase inhibitor deficiency.

Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs: An Update

After beta lactam antibiotics, hypersensitivity reactions to nonsteroidal anti-inflammatory drugs are the second cause of hypersensitivity to drugs. Acute manifestations affect the respiratory tract (aspirin exacerbated respiratory disease), the skin (urticaria and angioedema), or are generalized (anaphylaxis). Correct diagnosis and treatment in order to prevent unnecessary morbidity and the potential risk of death from these severe reactions, and to provide proper medical advice on future drug use frequently requires the participation of allergology specialists familiar with these clinical conditions.

Angioedema: clinical and etiological aspects

Angioedema is an abrupt swelling of the skin, mucous membrane, or both including respiratory and gastrointestinal tracts. This study aimed to report an experience of angioedema in a university hospital with respect to etiologies, clinical features, treatment, and outcome. One hundred and five patients were enrolled. About half had angioedema without urticaria. The common sites of involvement were periorbital area and lips. Forty five patients (49%) had systemic symptoms. The most common cause of angioedema was allergic angioedema. Nonsteroidal anti-inflammatory drug-induced angioedema and idiopathic angioedema were detected in 20% and 18%, respectively. Among patients with allergic angioedema, 41.7% were caused by food, 39.6% by drugs. Thirty seven patients (39%) had recurrent attacks of angioedema. Mean standard deviation (SD) number of attacks in patients with recurrent angioedema was 3.9 (2.7) (ranging from 2 to 10 times). Patients who had older age and multiple sites of skin involvement had tendency to have systemic symptoms.

Aspirin and nonsteroidal anti-inflammatory drug hypersensitivity

Acetylsalicylic acid (ASA) or aspirin and nonsteroidal anti-inflammatory drug (NSAID) sensitivities encompass a diverse group of both pharmacological and hypersensitivity reactions. Conventionally, hypersensitivities include aspirin-exacerbated respiratory disease (AERD), ASA-induced urticaria, and anaphylaxis. With an increasing prevalence of coronary artery disease in an aging population, aspirin continues to play a significant role in cardiac prophylaxis in a large patient population. Invariably, the clinician will encounter patients with clear indications for aspirin therapy but a history of aspirin sensitivity. Although protocols have been established for aspirin challenge and desensitization, it is not always an efficacious or safe procedure. This article reviews the different classifications of ASA/NSAIDs hypersensitivities to better guide the clinician in dealing with this patient population. History of crossrelativities between multiple NSAIDs implies a non-IgE-mediated process. Similarly, a history of monosensitivity to one NSAID implies an IgE-mediated process, although specific antibodies are often elusive. Despite the name, AERD can potentially be exacerbated by all cyclooxygenase (COX) inhibitors based on dose-dependent inhibition of COX-1. Aspirin desensitization can be achieved to improve both upper and lower respiratory symptoms for most patient with AERD. Aspirin desensitization can usually be achieved for those in need of the antiplatelet effects of aspirin, with the exception of those with aspirin-induced urticaria and baseline chronic urticaria. However, desensitization should only be attempted in those with stable coronary artery disease because the process of desensitization carries the inherent risk of anaphylaxis/anaphylactoid reaction, which may further increase cardiac demand and bring about ischemic injury. Therefore, desensitization is reserved until coronary artery disease is stabilized.

Clinical management of adult patients with a history of nonsteroidal anti-inflammatory drug-induced urticaria/angioedema: update

In the large majority of previous studies, patients with a history of acute urticaria induced by nonsteroidal anti-inflammatory drugs (NSAIDs) seeking safe alternative drugs have undergone tolerance tests uniquely with compounds exerting little or no inhibitory effect on the cyclooxygenase 1 enzyme. In light of recently published studies, however, this approach seems inadequate and should be changed. The present article critically reviews the clinical management of patients presenting with a history of urticaria induced by a single NSAID or multiple NSAIDs and suggests a simple, updated diagnostic algorithm that may assist clinicians in correctly classifying their patients.

Risk of skin reactions when using ibuprofen-based medicines

Adverse reactions to drugs are a frequent cause of morbidity and medical consultation; it is no surprise that nonsteroidal anti-inflammatory drugs (NSAIDs) run second, after antibiotics, mainly of the beta-lactam group (penicillins and cephalosporins). Numerous clinical pictures involving the skin--various morbilliform rashes, urticaria and angioedema as the most common--due to hypersensitivity to a particular NSAID (i.e., ibuprofen) have been described; other clinically defined skin diseases such as vasculitis, Steven-Johnson's syndrome, photosensitivity, fixed drug eruptions, livedo-like dermatitis, linear drug eruption, lichenoid drug eruption, exanthematous pustulosis, eczematous eruption, contact dermatitis and pemphigoid have received the attention of physicians. Extensive use around the world makes it interesting to investigate adverse cutaneous reactions to ibuprofen and other members of the propionic acid derivative group, to ascertain their prevalence, clinical presentation and prevention. This paper presents a review of published literature concerning cutaneous hypersensitivity reactions to ibuprofen and related arylpropionic acids.

NSAID-induced urticaria and angioedema: a reappraisal of its clinical management

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs), resulting in urticaria and angioedema, is being observed with increasing frequency. Prevalence rates range from 0.1-0.3%, which is partly due to the large size of the exposed (at risk) population. Some predisposing factors for these cutaneous reactions have been identified, among them atopic diathesis, female sex, young adulthood, a history of chronic urticaria and the use of the NSAID for the relief of acute pain. The description of two different arachidonic acid cyclo-oxygenases (COX) about a decade ago, designated COX-1 and COX-2, and the incorporation into the therapeutic armamentarium of more selective enzyme inhibitors for the control of inflammation and pain, has led to an improved understanding of the pathogenesis of adverse reactions to NSAIDs. This has allowed investigators to study 'sensitive' individuals to see if they can safely receive these new pharmaceutical compounds. The reasons why some people react to NSAIDs are not completely clarified. The prevalent theory about the pathogenesis of urticaria and angioedema due to NSAIDs in cross-reactive patients assumes that the inhibition of COX-1 leads to a shunting of arachidonic acid metabolism towards the 5-lipoxygenase pathway, which results in an increased synthesis and release of cysteinyl leukotrienes. Although COX-2 inhibitors are well tolerated by the majority of classic NSAID-sensitive patients, cutaneous reactions to highly selective inhibitors of COX-2 have been described in some of these individuals, casting some doubts about the relevance of such hypotheses. On the other hand, in patients who react to a single NSAID and chemically similar products (single-reactors), specific immunoglobulin E antibodies to haptenated NSAID metabolites have been suspected, although these metabolites are not easily demonstrated by means of routine in vivo or in vitro techniques. Facial (periorbital) angioedema constitutes the most common form of clinical presentation, and one-third of the patients show a mixed clinical pattern of cutaneous (urticaria and/or angioedema) and respiratory symptoms which include upper respiratory tract edema, rhinorrhea, cough, breathlessness and tearing. When necessary, diagnosis is confirmed by means of controlled peroral drug challenges done by experienced physicians in the hospital setting and test results are helpful for clinical management, which will be based on strict avoidance, and the use of alternative tolerated medications. This approach is specially indicated in hypersensitive patients with chronic medical conditions who require continuous NSAID therapy, such as those with arthritis and coronary heart disease.

Anaphylactic and anaphylactoid reactions to aspirin and other NSAIDs

Aspirin and non-steroidal antiinflammatory drugs (NSAIDs) may cause anaphylactic or anaphylactoid reactions. Constitutively-expressed cyclooxygenase (COX-1) inhibition is likely to be responsible for the cross-reactions and side effects associated with these drugs, as well as the anaphylactoid reactions sometimes seen in aspirin-sensitive respiratory disease. Though anaphylactic and anaphylactoid reactions may be clinically indistinguishable, they involve different mechanisms. Anaphylactic reactions are due to immediate hypersensitivity involving cross-linking of drug-specific IgE. Regardless of COX selectivity pattern, NSAIDs may function as haptens capable of inducing allergic sensitization. Unlike anaphylaxis, anaphylactoid reactions are most likely related to inhibition of COX-l by NSAIDS. Thus, an anaphylactoid reaction caused by a particular COX-1 inhibiting NSAID will occur with a chemically unrelated NSAID which also inhibits COX-1 enzymes. Selective COX-2 inhibitors appear to be safe in patients with a history of NSAID-related anaphylactoid reactions but can function as haptens, with resulting sensitization and anaphylaxis upon next exposure. This article will discuss the mechanisms, prevalence and population-based studies of anaphylactic and anaphylactoid reactions caused by aspirin and NSAIDs. The evaluation and management of patients suspected of having experienced an anaphylactic or anaphylactoid reaction to aspirin or other NSAIDs will also be reviewed.

Preventing and managing drug-induced anaphylaxis

Drug-induced anaphylaxis and anaphylactoid reactions have increased in frequency with more widespread use of pharmaceutical agents. Anaphylaxis is a systemic, severe immediate hypersensitivity reaction caused by immunoglobulin (Ig) E-mediated immunological release of mediators of mast cells and basophils. An anaphylactoid reaction is an event similar to anaphylaxis but is not mediated by IgE. The incidence of anaphylactic or anaphylactoid reactions differs amongst classes of medications. Antibacterials are the most usual offenders, and penicillins are the most studied. Other compounds commonly causing reactions include non-steroidal anti-inflammatory drugs, anaesthetics, muscle relaxants, latex and radiocontrast media. Prevention, if possible, is the purpose of detailed patient history taking and physical examination. Simple strategies can be employed to decrease the risk of anaphylaxis. These include consideration of the route of drug administration, identification of patients with known causes of anaphylaxis, and the knowledge that certain medications cross react and are contraindicated in those with known history of anaphylaxis. Tests are available, and include IgE-specific skin tests and radioallergosorbent tests. Penicillins are the only compounds whose antigenic determinants are well documented, it is therefore difficult to determine the negative predictive value of other compounds tested. Oral challenge remains an alternative, though entails risk. Desensitisation procedures, as well as gradual dose escalation protocols, are available and can be implemented based on patient history and diagnostic testing. The management of anaphylaxis is based on control of the airway, breathing and circulation. Treatment consists of epinephrine (adrenaline) and supportive measures. Rapid diagnosis and intervention are important in these life-threatening reactions. After stabilisation, all individuals with a documented history of anaphylaxis require a Medic-Alert bracelet or necklace, and an identification card for their wallet or purse.

Over-the-counter analgesics and antipyretics: a critical assessment

BACKGROUND

It is just 100 years since the introduction of aspirin to medicine. Since then, aspirin and its derivatives have been joined by acetaminophen, and the nonsteroidal anti-inflammatory drugs--ibuprofen, naproxen sodium, and ketoprofen--as the only over-the-counter (OTC) agents approved by the US Food and Drug Administration for the short-term treatment of pain, headache, dysmenorrhea, and fever. Recently the prescription use of aspirin has expanded to include a number of antiplatelet indications.

OBJECTIVE

The purpose of this paper is to review critically the history, mechanisms of action, efficacy, and tolerability of OTC analgesic and antipyretic products. Relatively new and potential future indications for these drugs are also discussed.

CONCLUSION

Although all of the OTC analgesic/antipyretic agents seem to share a common mechanism of prostaglandin inhibition, there are important differences in their pharmacology, efficacy, and side-effect profiles. Considering their often-unsupervised use, the risk-benefit ratio of this class of drugs has been extremely favorable. However, when used inappropriately, even these drugs pose significant risks to certain patient populations.

Anaphylactoid reactions due to nonsteroidal antiinflammatory drugs: clinical and cross-reactivity studies

BACKGROUND

Anaphylactoid reactions due to nonsteroidal antiinflammatory drugs have been described.

OBJECTIVE

To study the clinical characteristics of 21 patients with anaphylactoid reactions due to nonsteroidal antiinflammatory drugs and to determine the cross-reactivity to non-steroidal antiinflammatory drugs not involved in the previous reactions nor structurally related by means of single-blind, placebo-controlled drug challenges.

PATIENTS AND METHODS

Twenty-one patients who exhibited clinical evidence of anaphylactoid reactions after nonsteroidal antiinflammatory drugs were recruited for the study at the time of admission in Emergency Unit of our Hospital, Single-blind, placebo controlled oral challenges with nonsteroidal antiinflammatory drugs (except those reported by the patient as being responsible for the previous reaction), were performed in all patients.

RESULTS

Fifteen patients were woman and six man, with a mean age of 35.7 years (range 18 to 62 years). Thirteen patients (60%) were normal subjects without concomitant diseases. No increase in frequency of atopy in comparison to the general population was observed. Pyrazole derivatives were the most common nonsteroidal antiinflammatory drugs involved (71.3%). A tolerance to drugs included in drug challenge protocol was noted in all patients.

CONCLUSION

In our population, pyrazole derivatives were the most common nonsteroidal antiinflammatory drugs involved in anaphylactoid reactions. Most patients appeared to be otherwise normal subjects without concomitant disease and no cross-reactivity with other non-steroidal antiinflammatory drugs not involved in the anaphylactoid reaction nor structurally related was found.

Toxicity of nonsteroidal anti-inflammatory drugs. An overview of the epidemiological evidence

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used throughout the world. This paper reviews the epidemiological data linking NSAID administration with gastrointestinal, hepatic, renal, haematological, and hypersensitivity reactions. Meta-analysis has demonstrated that NSAIDs are associated with serious upper gastrointestinal disorders, with a relative risk of 2.7 in patients receiving NSAIDs compared with subjects not receiving NSAIDs. An increase in the dose and duration of NSAIDs and age > 60 are associated with an increase in the risk of upper gastrointestinal toxicity. The current data strongly support a causal relationship between NSAIDs and gastrointestinal disorders. Case-control studies have demonstrated an association between some NSAIDs and neutropenia, with a relative risk of between 3 and 9 in patients treated with NSAIDs compared with nonusers of these drugs. NSAIDs have also been linked with hypersensitivity reactions, although the incidence of such reactions is very low. However, there are inconsistent data on the potential associations between NSAIDs and renal disease, and there are no epidemiological studies linking NSAIDs with acute liver disease. Overall, the incidence of serious adverse reactions associated with NSAIDs is low, and this class of drugs can be regarded as being reasonably safe.

Pharmacoepidemiological perspectives

Parallel with increasing concerns about drug safety, the importance of drug surveillance and the application of epidemiologic techniques have grown rapidly during the past decades. The increasing use of computerized health care data facilitates the establishment of populations large enough (millions) to allow epidemiological studies. Such extensive studies are now being done routinely in North America. By the use of computerized pharmacy or billing records, drug exposure is linked to files which include diagnoses. These record-linkage systems provide "objective" drug histories for pharmacoepidemiological cohort and case-control studies and these large databases offer powerful tools for drug evaluation. A number of new drug-disease associations, many of potential importance for European populations, will be discovered through the increased use of large databases in North America. The European community needs to develop a strategy to respond to these overseas findings to protect society from either overreaction or underreaction to drug safety issues.

Major advances in international pharmacoepidemiology

Pharmacoepidemiology applies the principles of epidemiology to the problems of pharmacotherapy--particularly addressing society's need to know more about drug safety issues than the highly structured pre-approval clinical trials programs can provide. Thus, the concerns are truly international, and the approaches must also be international, tempered by the ability to generalize from one nation's experience, and by the availability of specialized research resources. Studying the impact of medical and medicinal interventions, the field is especially well-served by the major advances in computer system's support of medical settings and the multipurpose linked automated data base, linking automated pharmacy-dispensing data with same-population automated hospital discharge and other medical and demographic data. The development of such resources, the direction of their fruits to complement the hard work of hands-on traditional epidemiologic approaches in this field, the recruitment and support of trained researchers in the field, and the international coordination of policy and practice realistic to the capacity while responsive to the demand are all among the exciting challenges ahead.

Clinical safety of flurbiprofen

Data from 58 premarketing studies of the nonsteroidal antiinflammatory drug flurbiprofen were pooled for analyses of adverse drug reactions (ADRs). These studies included 5602 patients treated with flurbiprofen (N = 4123), aspirin (N = 1033), or placebo (N = 446) for varying durations. Diagnoses included rheumatoid arthritis, osteoarthritis, and other painful musculoskeletal conditions. In these studies serious upper gastrointestinal ADRs occurred in flurbiprofen-treated patients at less than one half the rate seen in aspirin-treated patients. The incidence of serious urinary tract ADRs was lower with flurbiprofen than with aspirin. The flurbiprofen group had no serious clinical ADRs related to the hemic/lymphatic system. The most common laboratory abnormality was a decrease in hematocrit, which occurred less often than in the aspirin group. We also evaluated serious flurbiprofen-related ADRs in 4370 patients in a variety of other studies and reviewed published reports of flurbiprofen clinical trials and case reports. These reviews showed no additional, unanticipated patterns of intolerance. These clinical safety data indicate that in the doses studied, flurbiprofen is a well tolerated agent for patients requiring nonsteroidal antiinflammatory drug therapy.

Pharmaco-epidemiological perspectives

Parallel with increasing concerns about drug safety, the importance of drug surveillance and the application of epidemiologic techniques have grown rapidly during the past decades. The increasing use of computerized health care data facilitates the establishment of populations large enough (millions) to allow epidemiological studies. Such extensive studies are now being done routinely in North America. By the use of computerized pharmacy or billing records, drug exposure is linked to files which include diagnoses. These record-linkage systems provide 'objective' drug histories for pharmaco-epidemiological cohort and case-control studies and these large data bases offer powerful tools for drug evaluation. A number of new drug-disease associations, many of potential importance for European populations, will be discovered through the increased use of large data bases in North America. The European community needs to develop a strategy to respond to these overseas findings to protect the society from either overreaction or underreaction to drug safety issues.

The basis for variability of response to anti-rheumatic drugs

The reasons for variability of response to anti-rheumatic drugs are myriad. All the factors that contribute to kinetic variability, for example, contribute to differences in response between individuals. Thus, differences in drug formulation, protein binding, drug metabolism and excretion, all contribute to variable responses. Further, factors which contribute to differential clinical response/toxicity must be considered. Here, age, gender, genetic background, weight, concomitant diseases and numerous environmental factors come into play. Among the environmental factors are such diverse elements as smoking, activity and diet. Finally our ability to measure change, be it in response or toxicity, is limited, introducing apparent variability (as much as real variability) into the equation. While we cannot, at present, delineate the contribution of each factor to individual variability, it is hoped that systematic, persistent effort will help us understand and then control these elements, leading to improved ability to individualize therapy and decrease the variability of response to anti-rheumatic drugs.