February 2019 Pharmacy Update

Antibiotic Resistance: Assessing Antibiotic Allergies

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As you may already be involved in various antibiotic stewardship initiatives in your practice, it is also imperative to highlight the importance of properly assessing and reassessing patient-reported allergies to antibiotics.

Facts

  1. Approximately 10% of Americans believe they have a penicillin allergy 1

    • Less than 1% of the population are truly allergic to penicillins

  2. 90% of patients labeled as penicillin-allergic were able to tolerate penicillin when evaluated 2
    • No true IgE-mediated reactions when tested by board-certified allergist
  3. About 80% of patients with true, documented (IgE-mediated) penicillin allergy lose sensitivity after 10 years 1
  4. When patients are listed as having a penicillin allergy, prescribers often prescribe broad-spectrum antibiotics, which are often costlier and may be suboptimal therapy 1,3
    • Leads to more adverse effects, antibiotic resistance, and “alert fatigue” for prescribers
  5. MYTH: Patients with a penicillin allergy will also experience allergic reactions with cephalosporins due to cross-reactivity
  6. FACT: Cross-reactivity rate between penicillins and cephalosporins is 3% 2

What can I do?

  1. Ask the right questions when conducting history and physicals for patients who report and have reported penicillin allergies
    • Document reaction type, date, and time of onset
    • See attached* for recommended questions to ask during allergy assessment
    • Update patient profile and EHR
  2. Counsel patients when prescribing antibiotics on possible reactions and when to seek MD or 911
    • ex: Upset stomach is a common side effect that usually goes away after a few doses and can be prevented if taken with food
  3. Refer patient to allergist for skin testing and challenge dose when appropriate
    • If skin testing is positive, use another antibiotic or refer for desensitization if necessary

 *Email SVHP Clinical Pharmacist for Allergy Questionnaire

 

 

References:

1. Joint Task Force on Practice Parameters representing the American Academy of Allergy, Asthma and Immunology; American College of Allergy, Asthma and Immunology; Joint Council of Allergy, Asthma and Immunology. Drug allergy: an updated practice parameter. Ann Allergy Asthma Immunol. 2010 Oct;105(4):259-273.
2. Gonzalez-Estrada A, Radojicic C. Penicillin allergy: a practical guide for clinicians. Cleve Clin J Med 2015;82(5):295–300 [PubMed: 25973877].
3. Albin S, Agarwal S. Prevalence and characteristics of reported penicillin allergy in an urban outpatient adult population. Allergy Asthmas Proc. 2014;35(6):489-494. doi: 10.2500/aap.2014.35.3791