Fluoroquinolone-Associated Anaphylaxis in Spontaneous Adverse Drug Reaction Reports in Germany

Drug Allergy Practice Parameter Updates to Incorporate Into Your Clinical Practice

The drug allergy practice parameter was developed to provide guidance on the diagnosis and management of drug hypersensitivity reactions. It was last updated in 2010. With the growth of research and evidence-based data since then, experts came together to update the practice parameter with a focus on sections that the work group deemed to have significant changes (or were not addressed) in the previous practice parameter. This review is a focused update on aspects of the practice parameter deemed to have the greatest impact on clinical practice and includes significant updates on diagnosis of antibiotic allergy including penicillin, cephalosporin, sulfonamide, fluoroquinolone, and macrolide allergies. Other topics include the evolution in our management approach to patients with aspirin/nonsteroidal anti-inflammatory drug allergy, diagnostic testing for delayed drug hypersensitivity and allergy to chemotherapeutics and biologics, and the key consensus-based statements for clinical practice. Specifically, the updated practice parameter helps allergists understand the place of 1- or 2-step drug challenges that are valuable tools often without the need for skin testing in many clinical situations. A proactive approach to delabeling penicillin allergy as well as unnecessary avoidance of safe antibiotic alternatives for patients with proven penicillin allergy is emphasized. New guidance is provided on management of patients with different phenotypes of aspirin and nonsteroidal anti-inflammatory drug hypersensitivity reactions. Approaches to delayed drug hypersensitivity and use of delayed intradermal and patch testing for specific phenotypes are reviewed. Lastly, practical approaches to management of patients with reactions to chemotherapeutics and biologics are discussed.

Allergenic and Mas-Related G Protein-Coupled Receptor X2-Activating Properties of Drugs: Resolving the Two

Since the seminal description implicating occupation of the Mas-related G protein-coupled receptor X2 (MRGPRX2) in mast cell (MC) degranulation by drugs, many investigations have been undertaken into this potential new endotype of immediate drug hypersensitivity reaction. However, current evidence for this mechanism predominantly comes from (mutant) animal models or in vitro studies, and irrefutable clinical evidence in humans is still missing. Moreover, translation of these preclinical findings into clinical relevance in humans is difficult and should be critically interpreted. Starting from our clinical priorities and experience with flow-assisted functional analyses of basophils and cultured human MCs, the objectives of this rostrum are to identify some of these difficulties, emphasize the obstacles that might hamper translation from preclinical observations into the clinics, and highlight differences between IgE- and MRPGRX2-mediated reactions. Inevitably, as with any subject still beset by many questions, alternative interpretations, hypotheses, or explanations expressed here may not find universal acceptance. Nevertheless, we believe that for the time being, many questions remain unanswered. Finally, a theoretical mechanistic algorithm is proposed that might advance discrimination between MC degranulation from MRGPRX2 activation and cross-linking of membrane-bound drug-reactive IgE antibodies.

A typical presentation of moxifloxacin-induced DRESS syndrome with pulmonary involvement: a case report and review of the literature

Background

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a kind of hypersensitivity drug reaction involving the skin and multiple internal organ systems. Moxifloxacin has rarely been reported to be a drug that is associated with DRESS syndrome. Lungs are less frequently involved in DRESS syndrome, but their involvements may herald more serious clinical processes. We present a rare typical case of moxifloxacin-induced DRESS syndrome with lungs involved. Valuable clinical data such as changes in the pulmonary imaging and pulmonary function tests was recorded. This case is important for the differential diagnosis of DRESS syndrome with lungs involved by providing clinical manifestations, CT imaging, pulmonary function tests, and biopsy pathological characteristics. The changes in pulmonary imaging and pulmonary function tests may help us understand the mechanism of DRESS syndrome further.

Case presentation

We report a case of a 47-year-old woman who was treated with oral moxifloxacin for community-acquired pneumonia. The patient subsequently developed a cough, fever, liver injury, skin rash, hematologic abnormalities, and shortness of breath (SOB) followed by pharyngeal herpes and peripheral neuritis. These symptoms, clinical lab index, and CT scan of the lungs improved after the withdrawal of moxifloxacin. The probability of moxifloxacin-induced DRESS syndrome was rated as “Definite”, with 7 scores graded by RegiSCAR. A literature search was also performed with “fluoroquinolones,” “moxifloxacin,” “ciprofloxacin,” “levofloxacin,” “delafloxacin,” and “DRESS” or “drug-induced hypersensitivity syndrome (DIHS)” as the keywords that were put into PubMed. The overall pulmonary involvement was approximately 9.1% (1/11). It is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. We summarized detailed clinical data, including pulmonary imaging and pulmonary function changes.

Conclusion

This is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. Prompt recognition and correct diagnosis can promote appropriate treatment and accelerate recovery. This case is important for us as a reference in the differential diagnosis of DRESS syndrome and helps us further understand the mechanism of DRESS syndrome.

Ligands and Signaling of Mas-Related G Protein-Coupled Receptor-X2 in Mast Cell Activation

Mas-related G protein-coupled receptor-X2 (MRGPRX2) is known as a novel receptor to activate mast cells (MCs). MRGPRX2 plays a dual role in promoting MC-dependent host defense and immunomodulation and contributing to the pathogenesis of pseudo-allergic drug reactions, pain, itching, and inflammatory diseases. In this article, we discuss the possible signaling pathways of MCs activation mediated by MRGPRX2 and summarize and classify agonists and inhibitors of MRGPRX2 in MCs activation. MRGPRX2 is a low-affinity and low-selectivity receptor, which allows it to interact with a diverse group of ligands. Diverse MRGPRX2 ligands utilize conserved residues in its transmembrane (TM) domains and carboxyl-terminus Ser/Thr residues to undergo ligand binding and G protein coupling. The coupling likely initiates phosphorylation cascades, induces Ca²⁺ mobilization, and causes degranulation and generation of cytokines and chemokines via MAPK and NF-κB pathways, resulting in MCs activation. Agonists of MRGPRX2 on MCs are divided into peptides (including antimicrobial peptides, neuropeptides, MC degranulating peptides, peptide hormones) and nonpeptides (including FDA-approved drugs). Inhibitors of MRGPRX2 include non-selective GPCR inhibitors, herbal extracts, small-molecule MRGPRX2 antagonists, and DNA aptamer drugs. Screening and classifying MRGPRX2 ligands and summarizing their signaling pathways would improve our understanding of MRGPRX2-mediated physiological and pathological effects on MCs.

Emerging Causes of Drug-Induced Anaphylaxis: A Review of Anaphylaxis-Associated Reports in the FDA Adverse Event Reporting System (FAERS)

BACKGROUND

Drug-induced anaphylaxis is a well-known adverse drug reaction for some drug classes, but emerging drug causes of anaphylaxis and novel mechanisms may contribute in unrecognized ways.

OBJECTIVE

We sought to determine the top drugs reported in association with anaphylaxis and anaphylaxis followed by death in the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

We reviewed the publicly available FAERS database from 1999 to 2019. Using search terms "anaphylactic shock" or "anaphylactic reaction" and sorting cases by generic drug names, we counted and trended reports to FAERS in which a drug was associated with anaphylaxis or anaphylaxis followed by death.

RESULTS

From 1999 to 2019, there were 17,506,002 adverse drug events reported in FAERS, of which 47,496 (0.27%) were reported as anaphylaxis. Excluding patients without age, sex, or country data, respectively, the median age of patients in reports of anaphylaxis was 52 (interquartile range: 28), 62.71% were female, and 13,899 of 34,381 (40.43%) reports were from the United States. There were 2984 of 47,496 (6.28%) reports of anaphylaxis followed by death. Top drug classes associated with anaphylaxis in FAERS were antibiotics, monoclonal antibodies (mAbs), nonsteroidal anti-inflammatory drugs, and acetaminophen. Top drug classes associated with anaphylaxis deaths were antibiotics, radiocontrast agents, and intraoperative agents. Linear regression demonstrated reports of anaphylaxis to mAbs increasing at an average rate of 0.77% of total anaphylaxis reports per year (95% confidence interval: 0.65, 0.88) from 2.00% in 1999 to 17.37% in 2019, faster than any other drug class.

CONCLUSION

Antibiotics were highly reported for anaphylaxis overall and anaphylaxis followed by death. Increasing reports were noted for anaphylaxis to mAb therapies.

Transferable Mechanisms of Quinolone Resistance from 1998 Onward

While the description of resistance to quinolones is almost as old as these antimicrobial agents themselves, transferable mechanisms of quinolone resistance (TMQR) remained absent from the scenario for more than 36 years, appearing first as sporadic events and afterward as epidemics. In 1998, the first TMQR was soundly described, that is, QnrA. The presence of QnrA was almost anecdotal for years, but in the middle of the first decade of the 21st century, there was an explosion of TMQR descriptions, which definitively changed the epidemiology of quinolone resistance. Currently, 3 different clinically relevant mechanisms of quinolone resistance are encoded within mobile elements: (i) target protection, which is mediated by 7 different families of Qnr (QnrA, QnrB, QnrC, QnrD, QnrE, QnrS, and QnrVC), which overall account for more than 100 recognized alleles; (ii) antibiotic efflux, which is mediated by 2 main transferable efflux pumps (QepA and OqxAB), which together account for more than 30 alleles, and a series of other efflux pumps (e.g., QacBIII), which at present have been sporadically described; and (iii) antibiotic modification, which is mediated by the enzymes AAC(6')Ib-cr, from which different alleles have been claimed, as well as CrpP, a newly described phosphorylase.

Quinolone Allergy

Quinolones are the second most common antibiotic class associated with drug-induced allergic reactions, but data on quinolone allergy are scarce. This review article discusses the available evidence on quinolone allergy, including prevalence, risk factors, diagnosis, clinical manifestations, cross-reactivity, and management of allergic reactions. Although the incidence of quinolone allergy is still lower than beta-lactams, it has been increasingly reported in recent decades, most likely from its expanded use and the introduction of moxifloxacin. Thorough patient history remains essential in the evaluation of quinolone allergy. Many diagnostic tools have been investigated, but skin tests can yield false-positive results and in vitro tests have not been validated. The drug provocation test is considered the test of choice to confirm a quinolone allergy but is not without risk. Evidence regarding cross-reactivity among the quinolones is limited and conflicting. Quinolone allergy can be manifested either as an immediate or delayed reaction, but is not uniform across the class, with moxifloxacin posing the highest risk of anaphylaxis. Quinolone should be discontinued when an allergic reaction occurs and avoided in future scenarios, but desensitization may be warranted if no alternatives are available.

Drug-induced anaphylactic reactions in children: A retrospective analysis of 159 validated spontaneous reports

PURPOSE

The main objective of this study was to analyze validated cases of drug-induced anaphylactic reactions in children with regard to incriminated drugs, clinical characteristics, and associated factors. A further objective was to compare differences in incriminated drugs and characteristics between validated cases and a reference excluding anaphylactic reaction cases (basic dataset).

METHODS

Spontaneous reports of anaphylactic reactions in children (0-17 years) registered between January 2000 to December 2016 were extracted from the adverse drug reaction database of the German Federal Institute for Drugs and Medical Devices. These reports were restricted to drugs for which at least four cases were found. After case validation, 159 reports remained (validated dataset) and were compared with the basic dataset (n = 12.168 reports) using inferential statistics.

RESULTS

Estimated yearly increase of reports (36.8 vs 0.1), most frequently incriminated drugs (antibiotics 30.2% vs 11%, analgesics/antipyretics 22.0% vs 5.6%; P values less than 0.001) and route of administration (38.4% vs 6.7%) differed between the validated dataset and the basic dataset. Validated cases differed in severity (higher with atracurium), reported symptoms (urticaria leading with analgesics), and associated factors (atopy/allergy rarely reported with antibiotics) depending on the incriminated drug class. In 13.8% (11.3% if excluding repeated readministration in one person) of the cases, the drug had not been tolerated before.

CONCLUSIONS

A heterogeneous clinical phenotype with differences in associated factors was observed, suggesting different underlying mechanisms triggered by the different drug groups. Occurrence of serious drug-induced anaphylactic reactions in children could be reduced by carefully considering patient history.

Drug-induced anaphylaxis: is it an epidemic?

PURPOSE OF REVIEW

The present review addresses the epidemiology, analyzes the current data and promotes global awareness of drug-induced anaphylaxis.

RECENT FINDINGS

Anaphylaxis is a medical emergency that may cause death! In the last decade, studies have shown an increasing incidence and prevalence of anaphylaxis.

SUMMARY

Drug-induced anaphylaxis fatalities have increased, and this syndrome remains underdiagnosed and undertreated.

Update on Quinolone Allergy

PURPOSE OF REVIEW

Quinolones are a group of synthetic antibiotics widely use as first-line treatment for many infections. There has been an increase in the incidence of hypersensitivity reactions to quinolones in recent years, likely due to increased prescription. The purpose of this review is to summarize the clinical pictures, the methods used for diagnosing and the management of allergic reactions to quinolones.

RECENT FINDINGS

Allergic reactions to quinolones can be immediate or delayed, being anaphylaxis and maculopapular exanthema respectively the most frequent clinical entities. A precise diagnosis is particularly difficult since clinical history is often unreliable, skin tests can induce false-positive results, and commercial in vitro test are not well validated. Therefore, drug provocation testing is considered the gold standard to establish diagnosis, which is not a risk-free procedure. Cross-reactivity between quinolones is difficult to predict due to the small number of patients included in the few published studies. Moreover, hypersensitivity to quinolones has also been associated with beta-lactam and neuromuscular blocking agent allergies, although further studies are needed to understand the underlying mechanisms. Avoidance of the culprit quinolone is indicated in patients with a diagnosis of hypersensitivity to these drugs. When quinolone treatment is the only therapeutic option available, desensitization is necessary. This review summarizes the complex diagnostic approach and management of allergic reactions to quinolones.

Immediate Hypersensitivity to Moxifloxacin with Tolerance to Ciprofloxacin: Report of Three Cases and Review of the Literature

Objective

To report 3 cases of immediate hypersensitivity reactions to moxifloxacin in patients who tolerated ciprofloxacin.

Case summaries

A 71-year-old man, a 44-year-old woman, and a 70-year-old woman with a history of a moxifloxacin reaction developed an immediate hypersensitivity reaction upon oral challenge with moxifloxacin in our Drug Safety Clinic. The reaction was mainly characterized by pruritus and urticaria, although dyspnea and hypotension were noted in the first and second patient, respectively. Two of the patients had negative oral challenge tests with ciprofloxacin and all 3 patients tolerated full treatment courses of oral ciprofloxacin. In all 3 cases, use of the Naranjo probability scale indicated a highly probable adverse drug reaction.

Discussion

Moxiffoxacin, similar to other fluoroquinolones, can cause immediate hypersensitivity reactions. Previous publications have reported both cross-reactivity and a lack of cross-reactivity among various fluoroquinolones. The 3 patients discussed demonstrated a lack of cross-reactivity between moxifloxacin and ciprofloxacin since they tolerated oral challenge tests and full treatment courses of ciprofloxacin. Moxifloxacin has unique side chains at positions 7 and 8 on its bicyclic ring structure. Antigenic specificity to particular side chains at positions 7 and 8 on the bicyclic ring structure of moxifloxacin may explain this lack of cross-reactivity. Higher reporting rates of anaphylaxis to moxifloxacin compared to other fluoroquinolones may also be related to side chain specificity, although definitive evidence for this is lacking.

Conclusions

Based on our experience, patients who develop immediate hypersensitivity reactions to moxifloxacin may receive ciprofloxacin therapy in an appropriately monitored setting if they have previously tolerated full treatment courses of ciprofloxacin. Research into whether there is a specific side chain reaction unique to moxifloxacin is warranted.

Usefulness of In Vivo and In Vitro Diagnostic Tests in the Diagnosis of Hypersensitivity Reactions to Quinolones and in the Evaluation of Cross-Reactivity: A Comprehensive Study Including the Latest Quinolone Gemifloxacin

Purpose

Reports evaluating diagnosis and cross reactivity of quinolone hypersensitivity have revealed contradictory results. Furthermore, there are no reports investigating the cross-reactivity between gemifloxacin (GFX) and the others. We aimed to detect the usefulness of diagnostic tests of hypersensitivity reactions to quinolones and to evaluate the cross reactivity between different quinolones including the latest quinolone GFX.

Methods

We studied 54 patients (mean age 42.31±10.39 years; 47 female) with 57 hypersensitivity reactions due to different quinolones and 10 nonatopic quinolone tolerable control subjects. A detailed clinical history, skin test (ST), and single-blind placebo-controlled drug provocation test (SBPCDPT), as well as basophil activation test (BAT) and lymphocyte transformation test (LTT) were performed with the culprit and alternative quinolones including ciprofloxacin (CFX), moxifloxacin (MFX), levofloxacin (LFX), ofloxacin (OFX), and GFX.

Results

The majority (75.9%) of the patients reported immediate type reactions to various quinolones. The most common culprit drug was CFX (52.6%) and the most common reaction type was urticaria (26.3%). A quarter of the patients (24.1%) reacted to SBPCDPTs, although their STs were negative; while false ST positivity was 3.5% and ST/SBPCDPTs concordance was only 1.8%. Both BAT and LTT were not found useful in quinolone hypersensitivity. Cross-reactivity was primarily observed between LFX and OFX (50.0%), whereas it was the least between MFX and the others, and in GFX hypersensitive patients the degree of cross-reactivity to the other quinolones was 16.7%.

Conclusions

These results suggest that STs, BAT, and LTT are not supportive in the diagnosis of a hypersensitivity reaction to quinolone as well as in the prediction of cross-reactivity. Drug provocation tests (DPTs) are necessary to identify both culprit and alternative quinolones.

Hypersensitivity to fluoroquinolones: The expression of basophil activation markers depends on the clinical entity and the culprit fluoroquinolone

Although fluoroquinolones (FQs) are generally well-tolerated antibiotics, increasing numbers of hypersensitivity reactions have been reported. These can be evaluated in vitro by basophil activation tests (BATs); however, sensitivity is not optimal. Many factors could influence sensitivity such as basophil activation markers. The objective of this study was to evaluate the influence of 2 different activations markers, CD63 and CD203c, on the sensitivity of BAT to FQ. We studied 17 patients with immediate allergic reactions to FQ. BAT was performed with moxifloxacin and ciprofloxacin using CD193 (CCR3) for basophil selection and CD203c or CD63 as activation markers. Stimulation with ciprofloxacin induced a significantly higher expression of CD63 in ciprofloxacin-allergic patients compared to moxifloxacin-allergic patients (P = 0.002). In patients allergic to moxifloxacin with anaphylactic shock, we have observed an increase in the percentage of cells that upregulate CD203c, whereas patients with anaphylaxis preferentially upregulate CD63. The best sensitivity-specificity was obtained using a cutoff of 3 and the culprit FQ, using CD203c for moxifloxacin-allergic patients (sensitivity = 36.4%; specificity = 94.4%), and CD63 for ciprofloxacin-allergic patients (sensitivity = 83.3%; specificity = 88.9%). A negative correlation was found between the upregulation of CD63 and CD203c and the time interval between the reaction occurrence and the performance of the test (Spearman r = -0.446; P < 0.001 for CD63 and Spearman r = -0.386; P < 0.001 for CD203c). The performance of BAT for FQ allergy must be optimized for each drug, taking into account possible differences in the stimulation mechanism that leads to the upregulation of different activation markers.

Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Antibiotics are used extensively in the treatment of various infections. Consequently, they can be considered among the most important agents involved in adverse reactions to drugs, including both allergic and non-allergic drug hypersensitivity [J Allergy Clin Immunol 113:832–836, 2004]. Most studies published to date deal mainly with reactions to the beta-lactam group, and information on hypersensitivity to each of the other antimicrobial agents is scarce. The present document has been produced by the Special Committee on Drug Allergy of the World Allergy Organization to present the most relevant information on the incidence, clinical manifestations, diagnosis, possible mechanisms, and management of hypersensitivity reactions to non beta-lactam antimicrobials for use by practitioners worldwide.

US-based emergency department visits for fluoroquinolone-associated hypersensitivity reactions

PURPOSE

To estimate the rate of hypersensitivity reactions per 100,000 prescription dispensings of fluoroquinolones based on care rendered in a nationally representative sample of US hospital emergency departments (ED).

METHODS

We analyzed the frequency of fluoroquinolone-associated hypersensitivity reactions using the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance system (2004-2010) in conjunction with US retail outpatient prescription data from IMS Health (2004-2010). We further categorized reaction severity into three subgroups (mild, moderate, and severe).

RESULTS

Based on 1422 cases of fluoroquinolone-associated hypersensitivity reactions and national drug utilization projections, we estimated risk of hypersensitivity reactions for moxifloxacin, ciprofloxacin, and levofloxacin. The absolute risk of a fluoroquinolone-related hypersensitivity reaction of any severity was low (44.0 (95% CI 34.8-53.3) ED visits/100,000 prescriptions); however, we identified a statistically significant difference in the relative risk (rate ratios) of seeking care in an ED attributed to moxifloxacin hypersensitivity compared to either levofloxacin or ciprofloxacin. For all reaction severities, the estimated ED visits/100,000 prescriptions were 141.3 (95% CI 99.9-182.7) for moxifloxacin, 40.8 (95% CI 31.5-50.0) for levofloxacin, and 26.3 (95% CI 20.8-31.9) for ciprofloxacin. When the rates were stratified by reaction severity category (mild or moderate-severe), moxifloxacin continued to be implicated in more ED visits per 100,000 prescriptions dispensed than either levofloxacin or ciprofloxacin.

CONCLUSION

Fluoroquinolones may cause hypersensitivity reactions requiring care in an ED, and relative to use, the rate of moxifloxacin-related hypersensitivity reactions is higher compared to levofloxacin or ciprofloxacin.

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.

Fluoroquinolone photodegradation influences specific basophil activation

Fluoroquinolones (FQs) are photoreactive drugs, but it is not known whether laboratory light exposure can influence the induction of photoproducts and modify in vitro test results. The basophil activation test (BAT) has proven to be useful for evaluating immunoglobulin E (IgE)-mediated hypersensitivity to FQs, with a higher percentage of positive responders with ciprofloxacin (CIP) than with moxifloxacin (MOX). We studied the effect of laboratory light on CIP and MOX degradation, and drug-protein conjugate formation, and its influence on the BAT for evaluating IgE-mediated hypersensitivity to FQs. The results showed an important decrease in fluorescence emission intensity under light compared to dark conditions for MOX, and that BAT positivity was lower in light (17.9%) than in dark (35.7%) conditions. No changes were found for CIP in either fluorescence emission intensity or BAT results (46.4% in both conditions). We can conclude that light exposure is a critical factor in BAT results when photolabile drugs like MOX are used. Therefore, light is important when interpreting in vitro results.

A case of levofloxacin-induced anaphylaxis with elevated serum tryptase levels

Levofloxacin, a fluoroquinolone and L-isomer of the racemate ofloxacin, has been approved for the treatment of acute and chronic bacterial infections. Gastrointestinal complaints are the most frequently reported adverse drug reactions to fluoroquinolones. Other adverse events include headache, dizziness, increased liver enzyme levels, photosensitivity, tachycardia, QT prolongation, and eruptions. Anaphylaxis has been documented as a rare adverse drug reaction to levofloxacin; however, diagnostic tests are needed to evaluate whether these reactions are the result of levofloxacin treatment. While the results of skin tests are considered unreliable due to false-positive responses, the oral provocation test is currently considered to be the most reliable test. Tryptase, a neutral protease, is the dominant protein component of secretory granules in human mast cells, and an increased serum concentration of tryptase is a highly sensitive indicator of anaphylaxis. Herein, we report a case of levofloxacin-induced anaphylaxis in which the patient exhibited elevated serum tryptase levels and a positive oral levofloxacin challenge test result. As anaphylaxis is potentially life-threatening, the administration of fluoroquinolones to patients who have experienced a prior reaction to this type of agent should be avoided.

Occupational rhinitis induced by capsaicin

Capsaicin is the spice component of red pepper. It can be easily inhaled, inducing a reproducible cough and provokes a secretory response from the human nasal mucosa. To date, there has been no report of occupational rhinitis (OR) caused by capsaicin. We report the case of a 44-year-old female mill worker who developed occupational rhinitis after 4 years of exposure to capsaicin. She developed nasal congestion, rhinorrhea, and itchy nose, which were all aggravated upon exposure at the workplace. The patient had negative responses to all common inhalant allergens, including capsaicin, by skin prick tests. The nasal provocation test with capsaicin showed that the nasal symptom score and eosinophil count increased 10 minutes after the provocation and decreased after 1 to 3 hours; no significant response was noted to house dust mite allergen. The patient's work-related rhinitis improved 1 month after she relocated and started pharmacological treatment. To our knowledge, this is the first case of OR caused by capsaicin exposure in the workplace. We provide evidence suggesting that OR may be mediated by a non-immunological mechanism.

Drug allergy: an updated practice parameter

Adverse drug reactions (ADRs) result in major health problems in the United States in both the inpatient and outpatient setting. ADRs are broadly categorized into predictable (type A and unpredictable (type B) reactions. Predictable reactions are usually dose dependent, are related to the known pharmacologic actions of the drug, and occur in otherwise healthy individuals, They are estimated to comprise approximately 80% of all ADRs. Unpredictable are generally dose independent, are unrelated to the pharmacologic actions of the drug, and occur only in susceptible individuals. Unpredictable reactions are subdivided into drug intolerance, drug idiosyncrasy, drug allergy, and pseudoallergic reactions. Both type A and B reactions may be influenced by genetic predisposition of the patient

In vitro evaluation of IgE-mediated hypersensitivity reactions to quinolones

BACKGROUND

  Hypersensitivity IgE-mediated reactions to quinolones are not easy to diagnose, with skin testing inducing false positive results. The aim of the study was to evaluate the in vitro-specific IgE response in patients with immediate allergic reactions to quinolones.

METHODS

  We evaluated 38 patients with confirmed immediate allergic reactions to quinolones. Those with anaphylaxis were considered allergic by clinical history, once other possible causes were ruled out, and those with urticaria by drug provocation. Sepharose-radioimmunoassay (RIA) and basophil activation test (BAT) with ciprofloxacin, moxifloxacin and levofloxacin were performed.

RESULTS

  The quinolones involved were moxifloxacin (N = 24), ciprofloxacin (N = 11) and levofloxacin (N = 3). Sepharose-RIA was positive in 12 cases (31.57%) and BAT in 27 (71.05%). With Sepharose-RIA, 8 (21%) were positive to ciprofloxacin, 7 (18.4%) to moxifloxacin and 7 (18.4%) to levofloxacin. With BAT, 23 (60.5%) were positive to ciprofloxacin, 12 (31.6%) to moxifloxacin and 8 (21%) to levofloxacin. The specificity of the Sepharose-RIA was demonstrated by inhibition tests. To confirm that the BAT results observed were IgE mediated, the PI3K inhibitor wortmannin was used, with this compound inhibiting the BAT when stimulated with anti-IgE and the different quinolones, but not when fMLP was used as the basophil stimulator. Sepharose-RIA and BAT were repeated in positive cases 1 year later, detecting a decrease in all cases, with four becoming negative.

CONCLUSION

  Immediate hypersensitivity reactions to quinolones do occur, with moxifloxacin being the drug most frequently involved. The BAT is a useful method for diagnosing patients. Specific IgE was demonstrated by Sepharose-RIA and inhibition assay.

Anaphylactoid reaction considered ciprofloxacin related: a case report and literature review

BACKGROUND

Although ciprofloxacin is a generally well-tolerated fluoroquinolone antibiotic, serious and life-threatening adverse events such as anaphylaxis and pulmonary edema have been described with its use. However, there is a lack of data in the scientific literature regarding these events.

OBJECTIVES

This report describes a case of an anaphylactoid reaction, considered probably ciprofloxacin related, that manifested as angioedema and later as pulmonary edema. This report also summarizes the available scientific evidence regarding the epidemiology, pathogenesis, and outcome of ciprofloxacin-associated anaphylactoid reactions.

METHODS

Previously reported cases were identified using a search of MEDLINE and EMBASE (years: 1960-June 2009; English-language articles; search terms: ciprofloxacin, anaphylactoid reaction, anaphylaxis, angioedema, and pulmonary edema). The references cited in these articles were examined to identify additional reports. CASE SUMMARY/RESULTS: A 25-year-old healthy white woman with a weight of 65 kg and normal renal function presented with pyelonephritis. She was administered ciprofloxacin 500 mg BID PO and ibuprofen 400 mg q6h PO as needed for pain control. The following day, angioedema and pulmonary edema developed and were thought to be probably associated with ciprofloxacin use (Naranjo adverse drug reaction probability scale score, 6). Ciprofloxacin treatment was discontinued and supportive care with ceftriaxone 1 g/d IV was provided, and the patient recovered after 1 week of hospitalization. The adverse drug reactions associated with the intake of fluoroquinolones most commonly affect the gastrointestinal system, central nervous system, and skin. The literature search identified 64 cases of anaphylactoid reaction considered probably ciprofloxacin related. Forty-two of these cases were described in large studies, with no detailed data reported. Detailed information on the dose of ciprofloxacin, the time period between ciprofloxacin administration and anaphylactoid reaction, clinical manifestations, and outcomes of these reactions was available in 22 cases described in case reports. Twelve of these cases were described in HIV- patients; 10 cases were described in HIV+ patients. All of the patients recovered, with the exception of 2 patients with HIV infection, who died (unknown cause of death in 1 case and toxoplasma encephalitis in the other case). Fourteen patients (including all of the patients with HIV infection) required hospitalization in the intensive care unit. According to the manufacturer of ciprofloxacin, pulmonary edema has been described as an adverse event associated with ciprofloxacin in <1% of treated patients. However, a search of the MEDLINE and EMBASE databases did not identify any documented reports of ciprofloxacin-associated pulmonary edema.

CONCLUSIONS

The patient described in this case report experienced an anaphylactoid reaction likely associated with ciprofloxacin use. Although anaphylactoid/ anaphylactic reactions are uncommon (<5% of cases) adverse events associated with ciprofloxacin and other fluoroquinolones, clinicians should be aware of this potentially life-threatening event, which might also lead to pulmonary edema even in the setting of normal renal function.

Safety profile of the fluoroquinolones: focus on levofloxacin

The fluoroquinolone class of antibacterial agents are among the most frequently prescribed drugs, with utility in a broad range of bacterial infections. Although very useful agents, the fluoroquinolones as a class are associated with a number of adverse events, some with considerable clinical significance. In the past 15-20 years, tolerability concerns have led to restrictions on the use of the fluoroquinolones and, in some instances, the withdrawal of agents from the market. This review focuses on the safety and tolerability of levofloxacin, a third-generation fluoroquinolone, relative to other fluoroquinolones. A literature search was performed of the MEDLINE database encompassing the dates 1980-2009, using as keywords the drug names levofloxacin and concurrently marketed fluoroquinolones combined with the words 'safety', 'adverse effect' or 'adverse drug reaction', or the name of the specific adverse effect. Adverse events commonly associated with the fluoroquinolones include gastrointestinal and CNS toxicity (most frequently headache and dizziness), as well as other adverse events including ECG abnormalities (for example QT interval prolongation), disrupted glucose metabolism, phototoxicity, tendon and joint disorders, hypersensitivity and skin disorders, and hepatic toxicity. Package inserts for the fluoroquinolones in Europe and the US contain warnings regarding these risks. US package inserts also carry 'black-box' warnings regarding the risk of tendon rupture and joint disorders with these agents; however, there is a substantial body of evidence to indicate that there are marked differences in the tolerability profiles of the individual agents within the fluoroquinolone class. These differences may be explained, at least in part, by structural differences: all fluoroquinolones share a basic quinolone core, with differences in specific side chains underlying the adverse event relationships. Furthermore, many of the fluoroquinolone-associated adverse effects and toxicities occur more frequently in patients with pre-existing risk factors, or in certain subpopulations. Notably, package inserts for the fluoroquinolones carry warnings regarding use in the elderly, paediatric patients and patients with pre-existing, or factors predisposing to, seizure disorders. Because of this, many adverse reactions with these agents could be prevented by improving patient screening and education. The recent withdrawal of gatifloxacin due to dysglycaemia makes it timely to review the safety and tolerability of the individual agents in this class. Overall, it appears that levofloxacin is relatively well tolerated, with low rates of clinically important adverse events such as CNS toxicity, cardiovascular toxicity and dysglycaemia.

Emergency department visits for antibiotic-associated adverse events

BACKGROUND

Drug-related adverse events are an under-appreciated consequence of antibiotic use, and the national magnitude and scope of these events have not been studied. Our objective was to estimate and compare the numbers and rates of emergency department (ED) visits for drug-related adverse events associated with systemic antibiotics in the United States by drug class, individual drug, and event type.

METHODS

We analyzed drug-related adverse events from the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project (2004-2006) and outpatient prescriptions from national sample surveys of ambulatory care practices, the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey (2004-2005).

RESULTS

On the basis of 6614 cases, an estimated 142,505 visits (95% confidence interval [CI], 116,506-168,504 visits) annually were made to US EDs for drug-related adverse events attributable to systemic antibiotics. Antibiotics were implicated in 19.3% of all ED visits for drug-related adverse events. Most ED visits for antibiotic-associated adverse events were for allergic reactions (78.7% of visits; 95% CI, 75.3%-82.1% of visits). One-half of the estimated ED visits were attributable to penicillins (36.9% of visits; 95% CI, 34.7%-39.2% of visits) and cephalosporins (12.2%; 95% CI, 10.9%-13.5%). Among commonly prescribed antibiotics, sulfonamides and clindamycin were associated with the highest rate of ED visits (18.9 ED visits per 10,000 outpatient prescription visits [95% CI, 13.1-24.7 ED visits per 10,000 outpatient prescription visits] and 18.5 ED visits per 10,000 outpatient prescription visits [95% CI, 12.1-25.0 ED visits per 10,000 outpatient prescription visits], respectively). Compared with all other antibiotic classes, sulfonamides were associated with a significantly higher rate of moderate-to-severe allergic reactions (4.3% [95% CI, 2.9%-5.8%] vs. 1.9 % [95% CI, 1.5%-2.3%]), and sulfonamides and fluoroquinolones were associated with a significantly higher rate of neurologic or psychiatric disturbances (1.4% [95% CI, 1.0%-1.7%] vs. 0.5% [95% CI, 0.4%-0.6%]).

CONCLUSIONS

Antibiotic-associated adverse events lead to many ED visits, and allergic reactions are the most common events. Minimizing unnecessary antibiotic use by even a small percentage could significantly reduce the immediate and direct risks of drug-related adverse events in individual patients.

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.

Pharmacovigilance of drug allergy and hypersensitivity using the ENDA-DAHD database and the GALEN platform. The Galenda project

Nonallergic hypersensitivity and allergic reactions are part of the many different types of adverse drug reactions (ADRs). Databases exist for the collection of ADRs. Spontaneous reporting makes up the core data-generating system of pharmacovigilance, but there is a large under-estimation of allergy/hypersensitivity drug reactions. A specific database is therefore required for drug allergy and hypersensitivity using standard operating procedures (SOPs), as the diagnosis of drug allergy/hypersensitivity is difficult and current pharmacovigilance algorithms are insufficient. Although difficult, the diagnosis of drug allergy/hypersensitivity has been standardized by the European Network for Drug Allergy (ENDA) under the aegis of the European Academy of Allergology and Clinical Immunology and SOPs have been published. Based on ENDA and Global Allergy and Asthma European Network (GA(2)LEN, EU Framework Programme 6) SOPs, a Drug Allergy and Hypersensitivity Database (DAHD((R))) has been established under FileMaker((R)) Pro 9. It is already available online in many different languages and can be accessed using a personal login. GA(2)LEN is a European network of 27 partners (16 countries) and 59 collaborating centres (26 countries), which can coordinate and implement the DAHD across Europe. The GA(2)LEN-ENDA-DAHD platform interacting with a pharmacovigilance network appears to be of great interest for the reporting of allergy/hypersensitivity ADRs in conjunction with other pharmacovigilance instruments.

Involvement of Mrp2 (Abcc2) in biliary excretion of moxifloxacin and its metabolites in the isolated perfused rat liver

Moxifloxacin is a novel antibacterial agent that undergoes extensive metabolism in the liver to the glucuronide M1 and the sulfate M2, which are eliminated via the bile. To investigate the role of the multidrug resistance-associated protein (Mrp2) as the hepatic transport system for moxifloxacin and its conjugates, livers of Wistar and Mrp2-deficient TR- rats were perfused with moxifloxacin (10 microM) in a single-pass system. Values for the hepatic extraction ratio (E) and clearance (Cl) were insignificantly higher in TR- rats than Wistar rats (0.193+/-0.050 vs 0.245+/-0.050 for E; 6.85+/-1.96 vs 8.73+/-1.82 mL min(-1) for Cl), whereas biliary excretion and efflux into perfusate over 60 min were significantly lower in the mutant rat strain. Cumulative biliary excretion of M1, M2 and moxifloxacin was significantly reduced to 0.027%, 19.1%, and 29.6% in the TR- rats compared with Wistar rats, indicating that the biliary elimination of M1 is mediated exclusively by Mrp2, whereas that of M2 and moxifloxacin seems to depend mostly on Mrp2 and, to a smaller extent, a further unidentified canalicular transporter. Moxifloxacin stimulates bile flow by up to 11% in Wistar rats, but not in TR- rats, further supporting an efficient transport of this drug and its glucuronidated and sulfated metabolites by Mrp2. Moxifloxacin (10 microM) also reversibly inhibited the Mrp2-mediated biliary elimination of bromsulphthalein in Wistar rats by 34%, indicating competition with the elimination of Mrp2-specific substrates. In conclusion, we found that Mrp2 mediates the biliary elimination of moxifloxacin and its glucuronidated and sulfated metabolites in rats. MRP2 may therefore play a key role in the transport of moxifloxacin and its conjugates into bile in humans.

Incidence of Allergic Reactions Associated with Antibacterial Use in a Large, Managed Care Organisation

BACKGROUND

Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly derived from spontaneous reports that cannot be used to accurately estimate incidence.

METHODS

This study estimated the drug-specific incidence of serious allergic reactions after fluoroquinolone, cephalosporin and phenoxymethylpenicillin potassium exposure, using claims for healthcare services with confirmation through medical record abstraction within a large health insurer database. Cohorts exposed to each antibacterial of interest (moxifloxacin, levofloxacin, ciprofloxacin, gatifloxacin, cephalosporins and penicillin) were identified, and followed for 14 days for anaphylaxis (9th revision of the International Classification of Diseases [ICD-9] code 995.0), other allergic drug reactions (ICD-9 995.2, 995.3) or cardiopulmonary resuscitation.

RESULTS

The incidence per 10,000 first dispensings of any allergic diagnosis made in the hospital or emergency department was similar for moxifloxacin (4.3; 95% CI 3.5, 5.3), penicillin (4.7; 95% CI 3.8, 5.7) and ciprofloxacin (5.4; 95% CI 4.4, 6.5). The incidence for moxifloxacin was lower than that for levofloxacin (8.7; 95% CI 7.4, 10.0), gatifloxacin (6.7; 95% CI 5.6, 7.9) and the cephalosporins (7.5; 95% CI 6.3, 8.8). The incidence of anaphylaxis/anaphylactoid reactions after first dispensings was similar for the fluoroquinolones: 0.1 (95% CI 0.0, 0.3) for ciprofloxacin, 0.3 (95% CI 0.1, 0.5) for moxifloxacin, 0.3 (95% CI 0.1, 0.6) for gatifloxacin and 0.5 (95% CI 0.3, 0.9) for levofloxacin; and comparable with that of the cephalosporins (0.2; 95% CI 0.0, 0.4) and penicillin (0.1; 95% CI 0.0, 0.3).

CONCLUSIONS

Anaphylactic reactions were rare and their incidence did not differ substantially among the drug groups studied. By determining the occurrence of reactions following defined exposures, these results provide a context for the interpretation of spontaneous reports of allergic reactions.