Drug desensitization

Case Report: Comprehensive Management of Pneumocystis Jiroveci Pneumonia (PJP) and Secondary Infections of Multiple-Drug Resistant Enterobacter cloacae complex and Pseudomonas aeruginosa in a Kidney Transplant Recipient with Sulfonamide Allergies

We report a case of pneumocystis jiroveci pneumonia (PJP) in a 46-year-old woman, who previously underwent kidney transplant for chronic renal failure. She did not receive PJP prophylaxis treatment for the history of sulfonamide allergies. Four months after renal transplantation, the patient had cough, chest tightness, and shortness of breath. Procalcitonin (PCT) (0.06 ng/mL) and C-reactive protein (CRP) (5.33 mg/L) were normal, but the level of 1, 3-β-D-glucan test (G test, 193.89 pg/mL) were elevated. Metagenomics next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) rapidly and accurately identified P. jiroveci. Through sulfonamide desensitization and sulfamethoxazole-trimethoprim (TMP-SMX) combined with caspofungin (CAS) treatment, PJP was controlled. However, the patients' conditions were worsen for the hospital-acquired secondary pulmonary infection. A second BALF mNGS identified Enterobacter cloacae complex and Pseudomonas aeruginosa carrying carbapenem drug resistance genes, which were confirmed by subsequent culture and antimicrobial susceptibility test within 3 days. Finally, symptoms, such as chest tightness, cough, and shortness of breath, were improved and she was discharged after combined treatment with meropenem (MEM), polymyxin B (PMB), CAS, and TMP-SMX. In this case, mNGS, culture, and drug susceptibility testing were combined to monitor pathogenic microbial and adjust medication. At present, there are no case reports of mNGS use and sulfonamide desensitization in a kidney transplant recipient with sulfonamide allergies.

Immediate and delayed hypersensitivity reactions to corticosteroids - prevalence, diagnosis and treatment

BACKGROUND

Corticosteroids, which are anti-inflammatory and immunosuppressive agents used for the treatment of various diseases including allergic disorders, can induce immediate and delayed hypersensitivity reactions. Although these reactions are not common, due to the wide usage of corticosteroid medications, corticosteroid hypersensitivity reactions are clinically important.

OBJECTIVE

In this review, we summarise the prevalence, pathogenetic mechanism, clinical manifestations, risk factors, diagnostic and therapeutic approach for corticosteroid-induced hypersensitivity reactions.

METHODS

An integrative review of the literature was conducted using PubMed searches (mainly large cohort-based studies) regarding the different aspects of corticosteroid hypersensitivity.

RESULTS

Hypersensitivity reactions to corticosteroids can be immediate or delayed and can follow all modes of corticosteroid administration. Prick and intradermal skin tests are useful diagnostic tools for immediate hypersensitivity reactions, patch tests are useful for delayed hypersensitivity reactions. According to the diagnostic tests an alternative (safe) corticosteroid agent should be administered.

CONCLUSION

Physicians of all medical disciplines should be aware that corticosteroids can cause (paradoxically) immediate or delayed allergic hypersensitivity reactions. The diagnosis of such allergic reactions is challenging since it is often difficult to distinguish between hypersensitivity reactions and deterioration of the basic inflammatory disease (e.g., worsening of asthma or dermatitis). Thus, a high index of suspicion is needed in order to identify the culprit corticosteroid.

Standards for practical intravenous rapid drug desensitization & delabeling: A WAO committee statement

Drug hypersensitivity reactions (DHRs) to intravenous drugs can be severe and might leave patients and doctors in a difficult position where an essential treatment or intervention has to be suspended. Even if virtually any intravenous medication can potentially trigger a life-threatening DHR, chemotherapeutics, biologics, and antibiotics are amongst the intravenous drugs most frequently involved in these reactions. Admittedly, suspending such treatments may negatively impact the survival outcomes or the quality of life of affected patients. Delabeling pathways and rapid drug desensitization (RDD) can help reactive patients stay on first-choice therapies instead of turning to less efficacious, less cost-effective, or more toxic alternatives. However, these are high-complexity and high-risk techniques, which usually need expert teams and allergy-specific techniques (skin testing, in vitro testing, drug provocation testing) to ensure safety, an accurate diagnosis, and personalized management. Unfortunately, there are significant inequalities within and among countries in access to allergy departments with the necessary expertise and resources to offer these techniques and tackle these DHRs optimally. The main objective of this consensus document is to create a great benefit for patients worldwide by aiding allergists to expand the scope of their practice and support them with evidence, data, and experience from leading groups from around the globe. This statement of the Drug Hypersensitivity Committee of the World Allergy Organization (WAO) aims to be a comprehensive practical guide on the technical aspects of implementing acute-onset intravenous hypersensitivity delabeling and RDD for a wide range of drugs. Thus, the manuscript does not only focus on clinical pathways. Instead, it also provides guidance on topics usually left unaddressed, namely, internal validation, continuous quality improvement, creating a healthy multidisciplinary environment, and redesigning care (including a specific supplemental section on a real-life example of how to design a dedicated space that can combine basic and complex diagnostic and therapeutic techniques in allergy).

Evaluation of desensitization protocols to betalactam antibiotics

WHAT IS KNOWN AND OBJECTIVE

Betalactam antibiotics are the most frequent cause of hypersensitivity reactions. Rapid drug desensitization (RDD) is a technique that induces temporary tolerance to a drug allowing a patient to receive the optimal agent. The increased use of RDD and the lack of standardization among available protocols in terms of formulation, starting dose, number of steps and dosing frequency make it essential to determine the safety and appropriate management of these protocols, especially regarding reconstitution, diluents, stability and drug administration in order to guarantee reproducibility. We reviewed betalactam desensitization protocols in a tertiary hospital, in accordance with currently published practices and evaluated its use on patients over a period of three years.

METHODS

(a) We performed a literature search in PubMed, MEDLINE and Google Scholar databases for case reports and/or systematic reviews describing desensitization protocols for betalactam antibiotics. Pharmacokinetic parameters and physicochemical stability were checked for each antibiotic. (b) We retrospectively reviewed inpatients undergoing our antibiotic desensitization protocols from February 2018 to January 2021. Data and outcomes of desensitization procedures were analysed.

RESULTS

We developed nine RDD protocols: meropenem, ceftriaxone, ceftazidime, ampicillin, ceftolozane/tazobactam, cloxacillin, piperacillin/tazobactam, amoxicillin/clavulanate and penicillin G sodium. Five antibiotics have RDD protocols for two different doses, adjusted to patients with impaired renal function. Detailed data (diluent, total dose, volume, concentrations, duration and stability) of the protocol of each antibiotic used are provided. 28 desensitizations were performed in 17 patients, three of them with confirmed allergies by skin test. 26 out of 28 (92.9%) of them were successfully completed, including those three with positive skin results. The pathogens most frequently involved were E. faecalis and P. aeruginosa; both frequently associated with bacterial resistance. Meropenem, ceftriaxone and ceftazidime were the antibiotics most desensitized. 25 out of 26 (96.1%) procedures were successful in resolving the infection.

WHAT IS NEW AND CONCLUSIONS

Detailed information about compounding, dilution and stability is crucial to ensure safe and successful desensitization processes, as well as good coordination between the Allergy and Pharmacy departments. The increase in bacterial resistance to many of the commercially available antibiotics limits the therapeutic options for treating multidrug-resistant infections; in those situations, antibiotic desensitization may be a key therapeutic option. Although there is a broad consensus in limiting the use of RDD to patients with confirmed allergy, in usual clinical practice its application in those strongly suspected of having type I hypersensitivity is still observed. Our betalactam desensitization protocols have shown themselves to be safe and effective, as evidenced by data from the 17 patients on whom they have been tested.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Aspirin Desensitization: Implications for Acetylsalicylic Acid-Sensitive Pregnant Women

Low-dose acetylsalicylic acid (ASA) is widely used during pregnancy to prevent obstetric complications of placental dysfunction, such as preeclampsia, stillbirth and fetal growth restriction, and obstetric complications in pregnant women with antiphospholipid syndrome. ASA-sensitive pregnant women cannot benefit from the effects of ASA due to the possibility of severe or potentially life-threatening hypersensitivity reactions to ASA. ASA desensitization is a valuable and safe therapeutic option for these women, allowing them to start daily prophylaxis with ASA and prevent pregnancy complications. The authors discuss the recent advances in obstetric conditions preventable by ASA and the management of ASA hypersensitivity in pregnancy, including ASA desensitization. To encourage the implementation of ASA desensitization protocols in ASA-sensitive pregnant women, they also propose a practical approach for use in daily clinical practice.

Anti-Opioid Antibodies in Individuals Using Chronic Opioid Therapy for Lower Back Pain

In addition to the risk of developing opioid use disorder (OUD), known side-effects of long-term opioid use include chronic inflammation and hyperalgesia, which may arise from immune responses induced following chronic opioid use. To investigate this hypothesis, blood samples were obtained from individuals with chronic back pain who were either chronically taking prescription opioids or had minimal recent opioid exposure. Patient samples were analyzed using an enzyme-linked immunosorbent assay (ELISA) against hydrocodone- or oxycodone-hapten conjugates to assess the levels of antibodies present in the samples. While no specific response was seen in opioid-naïve subjects, we observed varying levels of anti-opioid IgM antibodies in the exposed subjects. In these subjects, antibody formation was found to be weakly correlated with current reported daily opioid dose. Other drugs of abuse found to elicit an immune response have been shown to generate advanced glycation end-products (AGEs) through reaction with glucose and subsequent modification of self-proteins. Investigations into this potential mechanism of anti-opioid antibody production identified reduced the formation of reactive intermediate species upon norhydrocodone reaction with glucose in comparison with nornicotine, thus identifying potentially important differences in hapten processing to yield the observed adaptive immune response.

A Survey on Knowledge Gaps in Assessment and Management of Severe Drug Hypersensitivity Reactions: Multicenter Cross-Sectional Study of Australian Health Care Providers

Severe drug hypersensitivity reactions (DHRs) are often encountered by health care professionals (HCPs). We evaluated knowledge of doctors and pharmacists in the assessment and management of severe DHRs using a structured questionnaire. A cross-sectional study was conducted in 4 metropolitan hospital networks in Melbourne, Australia. A 13-question, scenario-based multiple-choice questionnaire to assess specific knowledge domains in drug hypersensitivity syndrome recognition, causality attribution, cross-reactivity patterns, appropriate diagnostic tests, and therapy was administered to HCPs of various vocation and specialty groups. Data were analyzed according to profession, self-reported experience, and preparedness in managing severe DHRs. Two hundred thirty-eight participants (45.0% senior doctors, 24.4% junior doctors, and 30.7% pharmacists) across a range of subspecialties achieved an overall median score of 7 (IQR, 5-8)-overall 55.6% correct responses to all questions-with senior doctors outperforming junior doctors and pharmacists (P < .001). The best performance by all participants was in DHR syndrome recognition (60.9%), and the poorest was in diagnostics/therapy (52.0%). HCP group and experience level were significantly associated with better performance in the knowledge domains of cross-reactivity and diagnostics/therapy (P = .003 and < .001, respectively), but not in the domains of syndrome recognition and causality attribution (P > .05). Levels of self-reported preparedness in DHR management were not associated with performance rates in any of the knowledge domains. This study demonstrated significant knowledge gaps in the recognition and management of severe drug hypersensitivity reactions. Targeted multidisciplinary education of staff caring for these patients is needed to improve knowledge gaps.

Guideline on diagnostic procedures for suspected hypersensitivity to beta-lactam antibiotics: Guideline of the German Society for Allergology and Clinical Immunology (DGAKI) in collaboration with the German Society of Allergology (AeDA), German Society for Pediatric Allergology and Environmental Medicine (GPA), the German Contact Dermatitis Research Group (DKG), the Austrian Society for Allergology and Immunology (ÖGAI), and the Paul-Ehrlich Society for Chemotherapy (PEG)

This guideline on diagnostic procedures for suspected beta-lactam antibiotic (BLA) hypersensitivity was written by the German and Austrian professional associations for allergology, and the Paul-Ehrlich Society for Chemotherapy in a consensus procedure according to the criteria of the German Association of Scientific Medical Societies. BLA such as penicillins and cephalosporins represent the drug group that most frequently triggers drug allergies. However, the frequency of reports of suspected allergy in patient histories clearly exceeds the number of confirmed cases. The large number of suspected BLA allergies has a significant impact on, e.g., the quality of treatment received by the individual patient and the costs to society as a whole. Allergies to BLA are based on different immunological mechanisms and often manifest as maculopapular exanthema, as well as anaphylaxis; and there are also a number of less frequent special clinical manifestations of drug allergic reactions. All BLA have a beta-lactam ring. BLA are categorized into different classes: penicillins, cephalosporins, carbapenems, monobactams, and beta-lactamase inhibitors with different chemical structures. Knowledge of possible cross-reactivity is of considerable clinical significance. Whereas allergy to the common beta-lactam ring occurs in only a small percentage of all BLA allergic patients, cross-reactivity due to side chain similarities, such as aminopenicillins and aminocephalosporins, and even methoxyimino cephalosporins, are more common. However, the overall picture is complex and its elucidation may require further research. Diagnostic procedures used in BLA allergy are usually made up of four components: patient history, laboratory diagnostics, skin testing (which is particularly important), and drug provocation testing. The diagnostic approach - even in cases where the need to administer a BLA is acute - is guided by patient history and risk - benefit ratio in the individual case. Here again, further studies are required to extend the present state of knowledge. Performing allergy testing for suspected BLA hypersensitivity is urgently recommended not only in the interests of providing the patient with good medical care, but also due to the immense impact of putative BLA allergies on society as a whole.

Protocols for drug allergy desensitization in children

Introduction: When a drug hypersensitivity reaction is proven, desensitization protocols allow the reintroduction of the molecule in patients for whom such therapy is essential. Through drug desensitization (DDS), a temporary immune tolerance is maintained for the single course of a specific therapy. In pediatrics, indications for such a procedure include children with chronic diseases, severe infectious diseases and/or malignancies, who have a proven drug hypersensitivity.Areas covered: We ran a search on PubMed and Web of Science for papers on DDS and on DDS in children. Most protocols and recommendations on DDS focus on adults and have been adapted for children. The best candidates for desensitization are children with a history of immediate, IgE-mediated drug allergy, but this therapy may be applied also in nonallergic hypersensitivities and in non-immediate reactions. Most protocols in literature focus on antibiotics, especially beta-lactams, on chemotherapeutic agents, and on monoclonal antibodies.Expert opinion: Pediatric allergists should cooperate with specialists in infectious diseases and onco-hematology to provide DDS to children in need. Standardized protocols and international guidelines are still needed to optimize such treatment and to implement it in clinical daily practice.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Association between HLA-A*3201 allele and oxcarbazepine-induced cutaneous adverse reactions in Eastern Han Chinese population

PURPOSE

To determine genetic associations between oxcarbazepine (OXC)-induced cutaneous adverse drug reactions (cADRs) and human leukocyte antigen (HLA) variants in the Eastern Han Chinese population.

METHODS

A total of 120 patients were enrolled in this study, including 30 subjects with OXC-induced cADRs (case group) and 90 OXC-tolerant patients (control group). High-resolution HLA genotyping was conducted for HLA-A, HLA-B, HLA-C, and HLA-DRB1, and allele frequencies were compared.

RESULTS

No patient carried the HLA-B *1502 allele in the case group, the frequency of HLA-B *1502 allele in the control group was 6.1%. HLA-A*3201 allele was detected in 13.3% of 30 patients with OXC-induced cADRs (4/30) and 0% of 90 OXC-tolerant patients (0/90). The difference in HLA-A*3201 frequency between the two groups was statistically significant [P = 0.004, odds ratio (OR) = 15.877, 95% confidence interval (CI) = 1.817-138.720].

CONCLUSIONS

Eastern Han Chinese patients with the HLA-A*3201 allele may be more susceptible to OXC-induced cADRs, while the HLA-B*1502 allele is not correlated with it. The precise association between HLA alleles and OXC-induced cADRs warrants further study.

Drug Allergy

Drug allergy is commonly encountered in clinical practice. It is an immunological response to a pharmaceutical agent. The clinical presentation can vary from mild cutaneous reactions to life-threatening conditions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Diagnosis is most often clinical, but investigations such as measurement of immunoglobulin E, patch testing, and skin biopsy may be required. In patients with a known drug allergy, the offending drug should be avoided. [Pediatr Ann. 2018;47(10):e419-e425.].

Evaluation of Pharmacy-Developed Antibiotic Desensitization Protocols

BACKGROUND

Parameters within reconstitution, storage, stability, and administration may be optimized according to the unique pharmacokinetics of each antibiotic to ensure a successful desensitization.

OBJECTIVE

The study aims to evaluate the successfulness and safety of antibiotic desensitization protocols developed by the pharmacy department at our institution.

METHODS

A retrospective study was conducted at an 800-bed, urban, tertiary care, academic medical center. A total of 36 patients 18 years of age or older, admitted to our intensive care units between March 2013 and July 2017, who underwent antibiotic desensitization utilizing our pharmacy developed protocols were included.

RESULTS

In 36 patients, 61 desensitization cases were identified and included; 17 (47%) were male, 27 (75%) were Caucasian, and the median age was 55 years (range 19-94). In all, 15 different antibiotics were administered for desensitization, with meropenem (n = 12, 20%), ampicillin (n = 7, 11%), piperacillin/tazobactam (n = 7, 11%), and penicillin (n = 7, 11%) being the most common; 59 (97%) of 61 desensitizations were completed successfully with or without experiencing reactions, and 53 (89%) of the successful desensitization cases were completed without reactions. Two cases were categorized as anaphylaxis, which was severe enough to terminate the desensitization process. Of the 59 cases successfully completed, the 6 (10%) cases that experienced reactions were managed successfully during desensitization with completion of the process. Conclusion and Relevance: The findings suggest that our pharmacy-developed antibiotic desensitization protocols are successful and safe and may be adapted by other institutions.

A successful desensitization protocol for horse-derived antithymocyte globulin in severe aplastic anemia

BACKGROUND

Horse antithymocyte globulin (h-ATG) (ATGAM(®) ) is the first choice of treatment in very severe patients with aplastic anemia who do not have any HLA matched sibling donor. h-ATG is a heterologous serum that may cause anaphylaxis. Alternative treatment strategies must be planned in case of hypersensitivity. Desensitization must be considered in patients without an alternative treatment of choice. We aimed to present the h-ATG desensitization protocol and consider its effectiveness in patients with aplastic anemia who are hypersensitized with h-ATG and do not have an alternative treatment of choice.

METHODS

Skin prick tests were performed with non-diluted solution in eight very severe patients with aplastic anemia who are followed up in Ege University Children's Hospital. Although skin prick test was found negative in these eight patients, different dilution h-ATG intradermal tests were performed and found positive in all patients. h-ATG desensitization program was started to these hypersensitized patients.

RESULTS

Desensitization program was started to six male and two female very severe patients with aplastic anemia whose ages were between seven and 19 yr (median: 12.9 yr). All of the patients completed the desensitization program. While local reaction was seen in two patients, systemic reaction was seen in one patient and late reaction was seen in one patient during and after desensitization program.

CONCLUSION

A successful desensitization program with h-ATG in children with aplastic anemia is presented. Even though there is not an exposure before to such high allergy potential heterologous serum, skin tests should be performed and desensitization must be started to patients who are hypersensitized to h-ATG. As the expected effectiveness of the treatment is so much, the desensitization protocol can be carried out safely and effectively with trained stuff although allergic reactions can be seen.

Late latent syphilis in a patient with end-stage renal disease and presumptive penicillin allergy

PURPOSE

Pharmacotherapy challenges in a case of late latent syphilis complicated by end-stage renal disease and presumptive penicillin allergy are described.

SUMMARY

A 58-year-old white woman was admitted to the hospital for symptoms including altered mental status, shortness of breath, and chest pain. The initial workup isolated syphilis immunoglobulin G antibody. A treponemal test was reactive, and a nontreponemal test was nonreactive; analysis of cerebrospinal fluid did not indicate neurosyphilis. The patient was diagnosed as having late latent syphilis of unknown duration, for which the standard treatment is intramuscular penicillin G benzathine 2.4 million units once weekly for three weeks. Given the patient's advanced renal disease and other serious comorbidities, there were concerns about the potential need for renal dosage adjustment and repeated desensitization. However, given the slow absorption and long half-life of penicillin G and published data indicating its safe use in the context of hemodialysis, the treating clinicians decided to proceed with penicillin G therapy at the usual dose after an oral penicillin desensitization protocol; repeat desensitization before two subsequent injections was not performed. The patient completed the full course of penicillin G without incident. Notably, skin testing was not performed to definitively establish penicillin allergy. Microbiological testing to determine a cure of syphilis was not performed.

CONCLUSION

After the completion of an oral desensitization protocol, the standard three-dose regimen of intramuscular penicillin G for late latent syphilis was safely administered to a hemodialysis patient without dosage adjustment or repeated desensitization.

Beta-Lactam Hypersensitivity and Cross-Reactivity

Penicillin is the most frequently reported cause of drug allergy, and cross-reactivity of penicillins with other beta-lactam antibiotics is an area of debate. This review evaluates the available data on immunoglobulin E-mediated penicillin hypersensitivity and cross-reactivity with cephalosporin, carbapenem, and monobactam antibiotics. A MEDLINE search was conducted from 1950 to October 2013, and selected references from review articles were also evaluated. There is a wide variety in reported incidences of cross-reactivity between penicillins and cephalosporins or carbapenems, with early retrospective studies suggesting up to 41.7% and 47.4% cross-reactivity, respectively. Conversely, the use of monobactam antibiotics is frequently employed in the case of a penicillin allergy, as prescribers believe that there is no cross-reactivity between the 2 drug classes. More recent prospective studies suggest that the rates of cross-reactivity with cephalosporins and carbapenems are <5% and <1%, respectively. Similarities in penicillin and cephalosporin side chains may play a role in cross-reactivity between these classes. Cross-reactivity with monobactams is essentially negligible; however, there are some clinical data to support an interaction between ceftazidime and aztreonam, due to the similarity of their side chains. The data reviewed suggest that avoidance of other beta-lactams in patients with type 1 hypersensitivity to penicillins should be reconsidered.

Human leukocyte antigen genotypes and trial of desensitization in patients with oxcarbazepine-induced skin rash: a pilot study

BACKGROUND

Skin rash associated with specific antiepileptic drugs occurs not infrequently and it usually necessitates discontinuation of the causative drugs. An alternative strategy is to desensitize the individual to the offending drug. We checked the human leukocyte antigen genotypes and conducted a pilot study to investigate the usefulness and safety of desensitization in pediatric patients with skin rash associated with oxcarbazepine.

METHODS

We enrolled 19 patients with epilepsy who had discontinued oxcarbazepine because of skin rash despite an initial good response and then became refractory to other antiepileptic drugs along with an individual with paroxysmal kinesigenic dyskinesia with a similar situation. High-resolution HLA-A and -B genotyping was performed to investigate the genetic risk. The desensitization began with 0.1 mg daily reaching 120 mg on the thirty-first day. Thereafter, the dose was increased at a rate of 12 mg/day.

RESULTS

Nineteen patients completed the desensitization protocol to a target dosage over 2-5 months. Five patients developed itching and erythema during desensitization, but the symptoms disappeared after withholding a dose increment transiently. There were no human leukocyte antigen genotypes relevant to aromatic antiepileptic drug-induced severe hypersensitivity reactions. The seizure frequency was reduced to less than at baseline in 18 individuals.

CONCLUSION

This study demonstrated 95% efficacy, including 42% seizure-free patients and the favorable tolerability of desensitization to oxcarbazepine in patients with intractable epilepsy and one patient with paroxysmal kinesigenic dyskinesia. Screening for sensitive human leukocyte antigen types and exclusion of severe hypersensitivity reactions should precede desensitization.

Penicillin allergy evaluation: experience from a drug allergy clinic in an Arabian Gulf Country, Kuwait

BACKGROUND

Hypersensitivity to penicillin has been studied worldwide, but data regarding patterns of sensitization in Arabian Gulf countries are scarce.

OBJECTIVE

To describe the patterns of penicillin hypersensitivity during a 6-year study in Kuwait in terms of demographics, type of the culprit drug, in vivo and in vitro allergy testing.

METHODS

One hundred and twenty-four patients referred to the drug allergy clinic for penicillin allergy were fully evaluated by skin prick and intradermal testing. Drug provocation test was done on patients with negative results.

RESULTS

A total of 124 patients were evaluated for penicillin allergy. Mean age was 37.8 (standard deviation, 12.7) years, range from 8 to 74 years. Thirty-nine male (31.5%) and 85 female patients (68.5%) were included. Diagnosis of penicillin allergy was confirmed in 46 patients (37.1%). Among the 44 confirmed allergic patients by skin evaluation we had 15 (34.1%) positive skin prick test, and 29 (65.9%) positive intradermal testing. Among patients with positive skin testing, 47.7% were positive to major determinant benzylpenicilloyl poly-L-lysine, 20.4% to minor determinant mixture, 50.0% to penicillin G and 40.9% to ampicillin; 13.6% of patients were positive to amoxicillin by skin prick test. One patient had a positive radioallergosorbent test and one had a positive challenge test.

CONCLUSION

Penicillin allergy is a common problem with an incidence of about one third in our study subjects.

Indications, protocols, and outcomes of drug desensitizations for chemotherapy and monoclonal antibodies in adults and children

Advances in the understanding of various malignancies and chronic inflammatory diseases has led to the development of better treatment options for prolonging patient survival and minimizing morbidity. The recognition of "first-line" chemotherapy and monoclonal agents for these conditions has given more urgency to the need to re-administer these drugs in cases of drug hypersensitivity reactions. Therefore, in these cases, not only is desensitization considered when there is no alternative therapy available but also when alternative treatments are considered therapeutically inferior and/or more toxic. In this article, we describe the steps involved in the evaluation of these patients, factors to consider before making a decision to desensitize, the implementation of desensitization protocols, and the outcomes of such procedures.

Desensitization in delayed drug hypersensitivity reactions -- an EAACI position paper of the Drug Allergy Interest Group

Drug hypersensitivity may deprive patients of drug therapy, and occasionally no effective alternative treatment is available. Successful desensitization has been well documented in delayed drug hypersensitivity reactions. In certain situations, such as sulfonamide hypersensitivity in HIV-positive patients or hypersensitivity to antibiotics in patients with cystic fibrosis, published success rates reach 80%, and this procedure appears helpful for the patient management. A state of clinical tolerance may be achieved by the administration of increasing doses of the previously offending drug. However, in most cases, a pre-existent sensitization has not been proven by positive skin tests. Successful re-administration may have occurred in nonsensitized patients. A better understanding of the underlying mechanisms of desensitization is needed. Currently, desensitization in delayed hypersensitivity reactions is restricted to mild, uncomplicated exanthems and fixed drug eruptions. The published success rates vary depending on clinical manifestations, drugs, and applied protocols. Slower protocols tend to be more effective than rush protocols; however, underreporting of unsuccessful procedures is very probable. The decision to desensitize a patient must always be made on an individual basis, balancing risks and benefits. This paper reviews the literature and presents the expert experience of the Drug Hypersensitivity Interest Group of the European Academy of Allergy and Clinical Immunology.

Management of multiple drug allergies in children

Children with multiple drug allergies are likely to require treatment with one or more of the drugs to which they may have had a reaction, when there is no alternate effective drug available. Detailed review of their history and/or use of appropriate diagnostic studies will help determine the potential safety of readministering the desired drug as well as the method for its readministration, most likely in the form of a drug challenge or desensitization. A practical approach to the diagnosis and treatment of children with multiple drug allergies is described in this review.

Desensitization to antibiotics in children

Drug hypersensitivity reactions can occur to almost all drugs and antibiotics are among the most common cause for this kind of reactions. Drug hypersensitivity may affect any organ or system, and manifestations range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. In case of infection, there is usually a safe antibiotic alternative. Nonetheless, in some cases, no alternative treatment exists for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance to a drug which can only be maintained by continuous administration of the medication responsible for the hypersensitivity reaction. Desensitization is mainly performed in IgE-mediated reactions. Increasing doses of the implicated drug are administered over a short period of time, until the therapeutic dose is achieved and tolerated. Very few studies confined to children are found in literature. Most of them are case reports. In general, the proposed desensitization schemes are similar to those used in adults differing only in the final dose administered. The purpose of this study is to review desensitization to antibiotics in children presenting and discussing three clinical practical cases of desensitization in this age group.

Overview of penicillin allergy

Allergy to penicillin is the most commonly reported antibiotic allergy. However, most patients who report a positive history of a prior reaction to penicillin are not found to be allergic to penicillin upon skin testing. Often, this history is vague or based on a parent's recollection of an event that occurred in the distant past. Avoidance of penicillin based on self-reported allergic history alone often leads to the use of an alternate antibiotic with greater cost or side effect profile. Patients with a negative skin test to both major and minor determinants may generally be given penicillin, with a statistical risk of developing an allergic reaction similar to that observed in the general population. A more cautious approach in these cases where the degree of suspicion is low, an allergic etiology is unproven, or there is a negative skin test, is to do a graded challenge. If the skin test is positive, an alternate antibiotic should be used. If, however, an alternate antibiotic is not available, then desensitization may be performed, but there are limitations to desensitization as well, and tolerance is not permanent. Avoidance of cephalosporins may be recommended in cases of penicillin allergy, but newer generation cephalosporins have demonstrate less cross-reactivity to penicillin than earlier generation ones. Desensitization protocols for cephalosporins are available but not standardized. The mechanisms of antibiotic sensitization are not clearly understood.

Outpatient aspirin desensitization for patients with aspirin hypersensitivity and cardiac disease

BACKGROUND

Cardiac disease is common and often treated with aspirin therapy. Patients who develop an immunoglobulin E (IgE) hypersensitivity reaction to aspirin must abort treatment and receive alternative antithrombotic agents. Aspirin desensitization is a therapeutic procedure that may allow patients with a history of hypersensitivity to safely resume aspirin treatment. A variety of inpatient desensitization protocols have been published for IgE-mediated reactions, but outpatient regimens have not been previously reported.

OBJECTIVE

We aimed to determine the efficacy and safety of a multiday outpatient aspirin desensitization protocol for patients with an IgE-mediated aspirin hypersensitivity.

METHODS

We retrospectively assessed the efficacy of a multidose aspirin desensitization protocol performed in a university allergy-immunology clinic between July 2006 and December 2009. Patients were referred for a diagnosis of aspirin hypersensitivity and required aspirin for cardiac disease treatment. The protocol involved 10 or 12 aspirin doses depending on the final dose of 81 or 325 mg. Patients were desensitized over 2 to 3 half-days and were able to return home in between desensitization sessions.

RESULTS

A total of 9 patients with cardiac disease and aspirin hypersensitivity underwent an outpatient multiday aspirin desensitization. Eight patients (89%) were successfully desensitized and 1 patient declined to continue with further desensitization. No adverse reactions requiring inpatient hospital care occurred during desensitization.

CONCLUSIONS

This novel outpatient multiday aspirin desensitization protocol was a safe and effective approach for the treatment of aspirin hypersensitivity in patients with cardiac disease who require aspirin therapy. This flexible protocol is convenient for patients by avoiding hospital admission and full-day time commitments.

Management of clopidogrel hypersensitivity without drug interruption

Clopidogrel hypersensitivity affects up to 6% of treated patients, often leading to discontinuation of the drug. Conventional desensitization protocols incorporate a washout period off medication that may be problematic after percutaneous coronary intervention because premature discontinuation of dual antiplatelet therapy is a major risk factor for stent thrombosis. The purpose of this study was to evaluate a strategy for treating clopidogrel hypersensitivity without drug interruption using corticosteroids and antihistamines to facilitate development of physiologic tolerance. The study population consisted of 25 consecutive patients who developed clopidogrel hypersensitivity after percutaneous coronary intervention and were managed with suppressive therapy using corticosteroids and antihistamines. Treatment success (resolution of hypersensitivity symptoms without interrupting clopidogrel) was assessed, in addition to duration of clopidogrel therapy and adverse cardiac events during late follow-up (mean 670 ± 630 days). The cohort included 19 men and 6 women with a mean age of 62 ± 9 years. Drug-eluting stents were used in 16 patients (64%). Clopidogrel hypersensitivity occurred 6 ± 2 days after drug initiation. Treatment included corticosteroids (5 patients), antihistamines (5 patients), or corticosteroids and antihistamines (15 patients). Patients treated with corticosteroids received tapering courses for a mean of 10 ± 8 days. Treatment was successful with sustained symptom resolution in 22 of 25 patients (88%). Clopidogrel therapy was continued in successfully desensitized patients for 417 ± 369 days and in patients with drug-eluting stents for 529 ± 376 days. There were no deaths, myocardial infarctions, or stent thrombosis during extended follow-up. In conclusion, clopidogrel hypersensitivity can be successfully treated using short-course corticosteroids and antihistamines without interrupting drug therapy. This technique enables long-term continuation of clopidogrel and confers a low risk of adverse cardiac events.

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

General considerations on rapid desensitization for drug hypersensitivity - a consensus statement

Drug hypersensitivity reactions can occur with most drugs, are unpredictable, may affect any organ or system, and range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. However, for certain patients, the particular drug may be essential for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance of a compound responsible for a hypersensitivity reaction. It is performed by administering increasing doses of the medication concerned over a short period of time (from several hours to a few days) until the total cumulative therapeutic dose is achieved and tolerated. It is a high-risk procedure used only in patients in whom alternatives are less effective or not available after a positive risk/benefit analysis. Desensitization protocols have been developed and are used in patients with allergic reactions to antibiotics (mainly penicillin), insulins, sulfonamides, chemotherapeutic and biologic agents, and many other drugs. Desensitization is mainly performed in IgE-mediated reactions, but also in reactions where drug-specific IgE have not been demonstrated. Desensitization induces a temporary tolerant state, which can only be maintained by continuous administration of the medication. Thus, for treatments like chemotherapy, which have an average interval of 4 weeks between cycles, the procedure must be repeated for every new course. In this paper, some background information on rapid desensitization procedures is provided. We define the drugs and drug reactions indicated for such procedures, describe the possible mechanism of action, and discuss the indications and contraindications. The data should serve as background information for a database (accessible via the EAACI-homepage) with standardized protocols for rapid desensitization for antibiotics, chemotherapeutic agents, monoclonal antibodies/fusion proteins, and other drugs.

Approach to the patient with drug allergy

Clinicians commonly encounter patients who report to have drug allergy. In a large part, such allergy corresponds to adverse drug reactions, which are not immune mediated. The incriminated drug need not always be avoided for further therapy. On the other hand, drug allergy may manifest in many unexpected clinical pictures and thus not be recognized. There is no single standardized diagnostic test to confirm the immune-mediated mechanism and to identify the causative drug. Therefore, immune-mediated drug hypersensitivity reactions and their causative drugs have to be considered by the constellation of exposure, timing, and clinical features, including the pattern of organ manifestation. Prior experience with the drug is also an important feature. An allergologic workup with additional investigation may provide some help. Patients should be informed carefully about their drug allergy, whereby symptoms, drug that elicits reaction, modes of diagnosis of drug allergy, and possibly alternatives should be indicated in their allergy passport.

Clopidogrel Hypersensitivity: A Novel Multi-Day Outpatient Oral Desensitization Regimen

BACKGROUND

Clopidogrel hypersensitivity has posed a problem for the acute treatment and long-term care of a particular patient population with coronary artery disease and stent placement. Patients with clopidogrel hypersensitivity have had an increased risk of hypersensitivity reactions, including anaphylaxis, if they ingest clopidogrel without undergoing an oral desensitization procedure. The previously published desensitization protocols have either been performed in the intensive care unit, requiring significant cost and healthcare utilization, or have required a full-day outpatient commitment on behalf of the patient.

OBJECTIVE

To determine whether a multi-day outpatient oral clopidogrel desensitization protocol is effective and safe for patients with clopidogrel hypersensitivity.

METHODS

gWe retrospectively assessed the efficacy of a 10-dose outpatient multiday clopidogrel desensitization protocol performed in a university allergy-immunology center from April 2006 to October 2008 in patients with clopidogrel hypersensitivity. Patients were desensitized over 2–3 half-day clinical visits and were able to go home between desensitization sessions. A preliminary cost analysis was performed using the average of actual costs for the outpatient clopidogrel desensitization procedure and was compared with the average cost for an inpatient oral desensitization completed at our institution.

RESULTS

Eight patients with coronary artery disease, cardiac stent placement, and clopidogrel hypersensitivity underwent an outpatient multi-day oral clopidogrel desensitization procedure. All patients were successfully desensitized with the multi-day protocol without complications. No patient had recurrence of allergic reaction 3 months after the procedure. A preliminary cost analysis demonstrated a lower cost for the outpatient compared to the inpatient oral clopidogrel desensitization protocol.

CONCLUSIONS

This outpatient 10-dose multi-day clopidogrel desensitization protocol is a safe and effective novel approach for the treatment of clopidogrel hypersensitivity in patients with coronary artery disease and cardiac stent placement. In addition to safety and efficacy, this protocol offers the patient the convenience of avoiding hospital admission or full-day time commitments.

Approach to the patient with drug allergy

Drug allergies are adverse drug reactions mediated by the specific immune system. Despite characteristic signs (eg, skin rash) that raise awareness for possible drug allergies, they are great imitators of disease and may hide behind unexpected symptoms. No single standardized diagnostic test can confirm the immune-mediated mechanism or identify the causative drug; therefore, immune-mediated drug hypersensitivity reactions and their causative drugs must be recognized by the constellation of exposure, timing, and clinical features including the pattern of organ manifestation. Additional allergologic investigations (skin tests, in vitro tests, provocation tests) may provide help in identifying the possible eliciting drug.

Allergic Cross-Sensitivity Between Penicillin, Carbapenem, and Monobactam Antibiotics: What are the Chances?

Objective:

To evaluate the literature on the allergic cross-reactivity between penicillin, carbapenem, and monobactam antibiotics.

Data Sources:

A MEDLINE search (1950–June 2008) of the English literature was performed using the search terms β-lactam, penicillin, monobactam, carbapenem, allergy, and cross-reactivity. References of review articles were also screened for inclusion.

Study Selection and Data Extraction:

All articles in English from the data source were identified. Studies whose primary goal was to evaluate drug hypersensitivity and the potential for cross-reactivity were evaluated.

Data Synthesis:

Many patients have reported penicillin allergies that have not been verified by skin testing; many healthcare providers avoid the use of other β-lactam antibiotics, namely carbapenems, in these patients due to fear of the potential for immunoglobulin E-mediated allergic cross-reactivity. A wide range of cross-reactivity between penicillins and carbapenems has been reported in various studies; however, more recent prospective studies have shown the incidence of cross-reactivity between penicillin and carbapenem skin tests to be around 1%. Additionally, many prescribers freely use the monobactam aztreonam in penicillin-allergic patients, believing there is no cross-reactivity between the 2 drugs. Although data support the lack of cross-reactivity between aztreonam and penicillins, immunology and some clinical data support an interaction between ceftazidime and aztreonam due to the similarity of their side chains.

Conclusions:

Although variability in cross-reactivity rates between β-lactam classes exists in the literature, the practice of avoiding carbapenems in penicillin-allergic patients should be reconsidered. With regard to monobactams, the administration of aztreonam in a patient with a ceftazidime allergy may carry an increased risk of type 1 hypersensitivity reactions and should be considered with caution. Additionally, the importance of obtaining a thorough patient history regarding the previous allergic event, proper documentation, and penicillin skin testing is re emphasized.

Allergies to sulfonamide antibiotics and sulfur-containing drugs

OBJECTIVE

To provide a literature review and clinical summary of the evaluation and management of sulfonamide drug reactions.

DATA SOURCES

Published English-language medical literature.

STUDY SELECTION

Selected trials of drug desensitization protocols.

RESULTS

Obtaining a detailed history is invaluable in assessing a history of reactions to sulfonamide medications, because allergy to these drugs remains a clinical diagnosis at present. Numerous efficacious drug desensitization protocols for management have been published and are reviewed in detail.

CONCLUSIONS

The term sulfa allergy is imprecise and misleading and therefore should be discouraged. There are important distinctions between sulfonylarylamines (antimicrobial sulfonamides), nonarylamine (nonantimicrobial) sulfonamides, and sulfones, with regard to allergic and other adverse drug reactions. Most reactions to sulfonylarylamines probably result from multifactorial immunologic and toxic metabolic mechanisms, whereas less is known about the precise mechanisms of reactions to other sulfur-containing drugs.

Phenytoin desensitization in a child with symptomatic localization-related epilepsy

We reported a child with refractory partial seizures successfully managed by clinical desensitization to phenytoin. The patient had ischemic brain lesions due to cardiopulmonary arrest at 39 weeks of corrected age. He had complex partial seizures refractory to several antiepileptic drugs since 4 years of age. At 8 years 1 month of age, phenytoin was first administered. Fever and maculopapular rashes appeared at 10 days after phenytoin initiation, and then the drug was discontinued. At 8 years 8 months of age, desensitization was attempted because of refractoriness of seizures to drugs other than phenytoin. Desensitization was started at 1mg daily, and then the dose was doubled every week. His seizures were controlled by 150mg/day of phenytoin in combination with primidone. No problems have been observed during desensitization.

Immediate Hypersensitivity to Rifampicin in 3 Patients: Diagnostic Procedures and Induction of Clinical Tolerance

BACKGROUND

Desensitization with drugs may be indicated in some clinical situations. Apart from large experiences with beta-lactam antibiotics and cotrimoxazole in HIV infection, experience with other drugs is limited. Rifampicin may elicit exanthema and urticaria, and their pathomechanisms are not known in detail. Since therapy with rifampicin may be indispensable in mycobacterial infections or against multiresistant Staphylococcus aureus, desensitization may be indicated in some patients.

OBJECTIVE

Report of immediate hypersensitivity to rifampicin and description of diagnostic and desensitization procedures.

METHODS

We report 3 patients with immediate urticarial reactions to rifampicin. Diagnostic procedures included skin and in vitro tests (specific IgE, lymphocyte transformation test, LTT, and CAST). The non-irritant cutoff concentration was evaluated in 24 volunteers. A 7-day desensitization procedure was used.

RESULTS

Only intradermal tests at a dilution of at least 1:10,000 (concentration of rifampicin approximately 0.006 mg/ml) were true positive, whereas in vitro tests (IgE, LTT and CAST) did not correctly identify hypersensitive patients. Two patients had positive accidental reexposure. All patients were successfully desensitized with rifampicin according to a slow 7-day protocol.

CONCLUSIONS

Rifampicin rarely elicits immediate hypersensitivity symptoms which may be diagnosed by intradermal skin tests. In vitro tests did not contribute to the diagnosis. Therefore, an IgE-mediated mechanism remains to be proven. Desensitization with rifampicin using different protocols has been reported. In our 3 cases, clinical tolerance to rifampicin was achieved using a 7-day protocol.

Aspirin Desensitization in the Treatment of Antiphospholipid Syndrome during Pregnancy in ASA-sensitive Patients

PROBLEM

Antiphospholipid syndrome (APS) is associated with thrombosis and poor pregnancy outcome in the presence of antiphospholipid antibodies (aPL). Patients with aPL have a high risk of foetal loss. However, with low-dose aspirin (acetylsalicylic acid; ASA) in combination with subcutaneous heparin, the chances of full-term delivery increase. Nevertheless, ASA treatment is avoided in pregnant, ASA-sensitive women with APS.

METHODS

Rapid oral challenge-desensitization to ASA was performed in four pregnant women with a history of APS and aspirin sensitivity. In three patients, desensitization was performed during pregnancy and before the next pregnancy in the fourth. Desensitization was carried out in the ICU using increasing doses of aspirin (0.1-125 mg) over a 24-hr period.

RESULTS

Successful ASA desensitization was achieved in all the patients. No severe side effects occurred during the desensitization test. Only one patient required a small oral dose of antihistamines.

CONCLUSIONS

Aspirin desensitization may be a safe alternative even during pregnancy if carefully monitored and permit patients with APS to receive treatment with ASA. This would constitute a new indication in pregnant women with APS and ASA sensitivity.

Drug hypersensitivity

Allergic drug reactions compose a small percentage of ADRs, yet they are commonly encountered in clinical practice, and physicians are taught routinely to question patients about these reactions during history taking. Among antibiotics, the immunochemistry of penicillins has been elucidated,leading to the development of validated skin test reagents to diagnose type 1 allergy. Currently, the temporary commercial unavailability of Pre-Pen makes accurate penicillin skin testing impossible; however, this important skin test reagent is expected to become available sometime in 2006. Type 1 allergies to most other drugs lack comparable diagnostic tests, and their diagnosis is therefore driven by the patient's history. When readministration of medications to which patients report previous reactions is indicated, it may be almost always successfully accomplished by means of either graded challenge or desensitization.