Costs of beta-lactam allergies: selection and costs of antibiotics for patients with a reported beta-lactam allergy

Arch Fam Med. 2000 Aug;9(8):722-6. doi: 10.1001/archfami.9.8.722.


Objective: To evaluate antibiotic selection and the cost effect of reported beta-lactam allergies.

Design: Retrospective medical records review comparing antimicrobial selection and costs in patients with a reported beta-lactam allergy with a group in which no such allergy had been documented.

Setting: University-based family medicine clinic.

Patients: Patients who were prescribed at least 1 antibiotic for an upper respiratory tract infection, otitis media, sinusitis, and/or a urinary tract infection were eligible. One thousand two hundred one patients were identified via ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) codes. Four hundred sixty-five patients were initially identified and an additional 195 family members were eligible for inclusion.

Main outcome measures: Comparison of antimicrobial selection and costs (by average wholesale price) between patients with and without a reported beta-lactam allergy.

Results: Of the 660 patients eligible for inclusion, 99 (15%) had a documented beta-lactam allergy. Of the patients with a documented allergy, only 33% had a description of their purported reaction. The mean antibiotic cost for patients with a beta-lactam allergy was significantly higher compared with those without a beta-lactam allergy ($26.81 vs $16.28, respectively; P =.004). Patients with a beta-lactam allergy were more likely to have received a cephalosporin, macrolide, or a miscellaneous agent (eg, quinolone, tetracycline, or nitrofurantoin) (P =.001).

Conclusions: Patients with a beta-lactam allergy had higher antibiotic costs and were more likely to receive a broader-spectrum antibiotic. Most patients with a reported allergy did not have a description of their reaction. Skin testing may be of use in detecting true beta-lactam allergies; however, further study is needed to determine its cost-effectiveness.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / adverse effects*
  • Anti-Bacterial Agents / economics*
  • Child
  • Child, Preschool
  • Colorado
  • Drug Costs / statistics & numerical data*
  • Drug Hypersensitivity / economics*
  • Drug Hypersensitivity / etiology*
  • Female
  • Humans
  • Infant
  • Male
  • Medical Records
  • Middle Aged
  • Retrospective Studies
  • United States
  • beta-Lactams


  • Anti-Bacterial Agents
  • beta-Lactams