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Aging with Penicillin Allergy. What Is Real?
AB30 Abstracts
SATURDAY
99
Aging with Penicillin Allergy. What Is Real?
Francisco Javier Iglesias-Souto, MD, PhD1, Fernando RodriguezFernandez, MD, PhD2, and Victor Matheu, MD, PhD3; 1Hospiten Sur, Santa Cruz de Tenerife, Spain, 2Hospital Universitario Marques Valdecilla-IDIVAL, Santander, Spain, 3Hospital del Torax, Complejo Hospital Universitario Nuestra S. de Candelaria, Santa Cruz de Tenerife, Spain. RATIONALE: Penicillin allergy remains the most common drug allergy. Epidemiological studies of penicillin allergy in outpatient populations is relatively scarce. There are a large number of patients labelled as allergic to drugs commonly used in clinical practice without having been studied. This creates a major health resource problem, having to use alternative antibiotics. METHODS: A retrospective review of medical records was performed in patients over 60, studied by adverse reactions to penicillin for a period of 10 years. Diagnosis was supported by in vivo testing including skin test such as prick and intradermal test. Whether skin tests were negative a singleblind challenge or Drug Provocation Test was performed under medical surveillance to establish or exclude the diagnosis of penicillin allergy and, in selected cases, to provide alternative drugs for the patient in need. A total of 652 patients over 60 were studied for penicillin allergy, during a period of 10 years. RESULTS: The results of the study show 90 positive cases (13,8%) of penicillin allergy. Most positive cases were detected by skin tests (n567). Benzylpenicillins were the betalactam group most frequently involved in adverse reactions studied (34,7%, n5226), contrary to current consumption pattern. CONCLUSIONS: The label of penicillin allergy is quite often erroneous. This involves using of more expensive and less effective therapeutic alternatives, which also facilitate the emergence of multiresistant micro-organisms. Hence the importance of confirming the diagnosis of allergy.
100
Reflexive Penicillin Allergy Testing with InHospital Aztreonam Use
Justin R. Chen, MD1, Scott A. Tarver, PharmD2, Kristin S. Alvarez, PharmD1,2, Chi Nguyen2, and David A. Khan, MD, FAAAAI1; 1 University of Texas Southwestern Medical Center, Dallas, TX, 2Parkland Health and Hospital System, Dallas, TX. RATIONALE: Aztreonam is considered safe for administration in penicillin-allergic patients. However, most patients reporting penicillin allergies are in fact tolerant, leading to unnecessary use of this expensive broad-spectrum antibiotic. We present an initiative to reflexively bundle penicillin allergy testing with inpatient aztreonam orders. METHODS: An electronic panel was implemented linking penicillin allergy consultations with any aztreonam order. Individual providers could retain or remove the request (i.e. no penicillin allergy) at their discretion. Consults were reviewed on weekdays by an allergy-trained clinical pharmacist who performed inpatient penicillin skin testing and challenges. Patients with negative tests had their penicillin allergies removed from the record. RESULTS: 30 consultations were placed over a 3 month period for aztreonam recipients reporting penicillin allergy. 11 (36%) were tested, all of whom were negative and subsequently cleared for penicillin. The median time from admission to test was 1.05 days [IQR 0.62-2.54], reduced from 3.69 days [IQR 1.39-6.95] for 22 patients receiving aztreonam in the 15 months prior (p50.013). The most common reasons for not testing included antihistamine use (23%), discharge before being seen (20%), inability to consent (13%), and patient refusal (7%). Patients testing negative then accumulated 30.6 inpatient days of beta-lactam therapy with
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
direct antibiotic costs of $326.47. In contrast, an identical duration of aztreonam 1-2g per dose costs $1,836.92 to $3,963.92, a projected savings of 82-92% or $137.31-$330.67 per patient. CONCLUSIONS: Including allergy testing with orders of high-cost aztreonam facilitates early awareness and removal of inaccurate penicillin allergy diagnoses. This decreases superfluous antibiotic use and financially benefits healthcare institutions.
SATURDAY
99
Aging with Penicillin Allergy. What Is Real?
Francisco Javier Iglesias-Souto, MD, PhD1, Fernando RodriguezFernandez, MD, PhD2, and Victor Matheu, MD, PhD3; 1Hospiten Sur, Santa Cruz de Tenerife, Spain, 2Hospital Universitario Marques Valdecilla-IDIVAL, Santander, Spain, 3Hospital del Torax, Complejo Hospital Universitario Nuestra S. de Candelaria, Santa Cruz de Tenerife, Spain. RATIONALE: Penicillin allergy remains the most common drug allergy. Epidemiological studies of penicillin allergy in outpatient populations is relatively scarce. There are a large number of patients labelled as allergic to drugs commonly used in clinical practice without having been studied. This creates a major health resource problem, having to use alternative antibiotics. METHODS: A retrospective review of medical records was performed in patients over 60, studied by adverse reactions to penicillin for a period of 10 years. Diagnosis was supported by in vivo testing including skin test such as prick and intradermal test. Whether skin tests were negative a singleblind challenge or Drug Provocation Test was performed under medical surveillance to establish or exclude the diagnosis of penicillin allergy and, in selected cases, to provide alternative drugs for the patient in need. A total of 652 patients over 60 were studied for penicillin allergy, during a period of 10 years. RESULTS: The results of the study show 90 positive cases (13,8%) of penicillin allergy. Most positive cases were detected by skin tests (n567). Benzylpenicillins were the betalactam group most frequently involved in adverse reactions studied (34,7%, n5226), contrary to current consumption pattern. CONCLUSIONS: The label of penicillin allergy is quite often erroneous. This involves using of more expensive and less effective therapeutic alternatives, which also facilitate the emergence of multiresistant micro-organisms. Hence the importance of confirming the diagnosis of allergy.
100
Reflexive Penicillin Allergy Testing with InHospital Aztreonam Use
Justin R. Chen, MD1, Scott A. Tarver, PharmD2, Kristin S. Alvarez, PharmD1,2, Chi Nguyen2, and David A. Khan, MD, FAAAAI1; 1 University of Texas Southwestern Medical Center, Dallas, TX, 2Parkland Health and Hospital System, Dallas, TX. RATIONALE: Aztreonam is considered safe for administration in penicillin-allergic patients. However, most patients reporting penicillin allergies are in fact tolerant, leading to unnecessary use of this expensive broad-spectrum antibiotic. We present an initiative to reflexively bundle penicillin allergy testing with inpatient aztreonam orders. METHODS: An electronic panel was implemented linking penicillin allergy consultations with any aztreonam order. Individual providers could retain or remove the request (i.e. no penicillin allergy) at their discretion. Consults were reviewed on weekdays by an allergy-trained clinical pharmacist who performed inpatient penicillin skin testing and challenges. Patients with negative tests had their penicillin allergies removed from the record. RESULTS: 30 consultations were placed over a 3 month period for aztreonam recipients reporting penicillin allergy. 11 (36%) were tested, all of whom were negative and subsequently cleared for penicillin. The median time from admission to test was 1.05 days [IQR 0.62-2.54], reduced from 3.69 days [IQR 1.39-6.95] for 22 patients receiving aztreonam in the 15 months prior (p50.013). The most common reasons for not testing included antihistamine use (23%), discharge before being seen (20%), inability to consent (13%), and patient refusal (7%). Patients testing negative then accumulated 30.6 inpatient days of beta-lactam therapy with
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
direct antibiotic costs of $326.47. In contrast, an identical duration of aztreonam 1-2g per dose costs $1,836.92 to $3,963.92, a projected savings of 82-92% or $137.31-$330.67 per patient. CONCLUSIONS: Including allergy testing with orders of high-cost aztreonam facilitates early awareness and removal of inaccurate penicillin allergy diagnoses. This decreases superfluous antibiotic use and financially benefits healthcare institutions.