Impact of a clinical guideline for prescribing antibiotics to inpatients reporting penicillin or cephalosporin allergy

Ann Allergy Asthma Immunol. 2015 Oct;115(4):294-300.e2. doi: 10.1016/j.anai.2015.05.011. Epub 2015 Jun 9.


Background: Self-reported penicillin allergy infrequently reflects an inability to tolerate penicillins. Inpatients reporting penicillin allergy receive alternative antibiotics that might be broader spectrum, more toxic, or less effective.

Objective: To develop and assess a clinical guideline for the general inpatient provider that directs taking a history and prescribing antibiotics for patients with penicillin or cephalosporin allergy.

Methods: A guideline was implemented to assist providers with assessing allergy history and prescribing antibiotics for patients with reported penicillin or cephalosporin allergy. The guideline used a standard 2-step graded challenge or test dose. A quasi-experimental study was performed to assess safety, feasibility, and impact on antibiotic use by comparing treatment 21 months before guideline implementation with 12 months after guideline implementation.

Results: Significantly more test doses to β-lactam antibiotics were performed monthly after vs before guideline implementation (median 14.5, interquartile range 13-16.25, vs 2, interquartile range 1-3.25, P < .001). Seven adverse drug reactions occurred during guideline-driven test doses, with no significant difference in rate (3.9% vs 6.1%, P = .44) or severity (P > .5) between periods. Guideline-driven test doses decreased alternative antimicrobial therapy after the test dose, including vancomycin (68.3% vs 37.2%, P < .001), aztreonam (11.5% vs 0.5%, P < .001), aminoglycosides (6.0% vs 1.1%, P = .004), and fluoro quinolones (15.3% vs 3.3%, P < .001).

Conclusion: The implementation of an inpatient antibiotic prescribing guideline for patients with penicillin or cephalosporin allergy was associated with an almost 7-fold increase in the number of test doses to β-lactams without increased adverse drug reactions. Patients assessed with guideline-driven test doses were observed to have significantly decreased alternative antibiotic exposure.

MeSH terms

  • Anti-Bacterial Agents / adverse effects*
  • Anti-Bacterial Agents / therapeutic use
  • Cephalosporins / administration & dosage
  • Cephalosporins / adverse effects*
  • Drug Hypersensitivity / epidemiology*
  • Drug Hypersensitivity / etiology
  • Drug Prescriptions / standards*
  • Female
  • Humans
  • Inpatients
  • Male
  • Middle Aged
  • Penicillins / administration & dosage
  • Penicillins / adverse effects*
  • Practice Guidelines as Topic / standards*
  • Practice Patterns, Physicians'
  • Self Report
  • Skin Tests


  • Anti-Bacterial Agents
  • Cephalosporins
  • Penicillins