Vancomycin Hypersensitivity Reactions Documented in Electronic Health Records

Area of Science:

• Pharmacovigilance
• Clinical Informatics
• Allergy and Immunology

Background:

• Vancomycin is a critical antimicrobial in US hospitals, frequently associated with hypersensitivity reactions (HSRs).
• Existing electronic health record (EHR) data inadequately capture the nuances of vancomycin-induced adverse drug reactions (ADRs).

Purpose of the Study:

• To characterize the epidemiology of vancomycin HSRs using EHR allergy data.
• To analyze trends and phenotypes of vancomycin drug allergy labels (DALs).

Main Methods:

• A cross-sectional study analyzed EHR data from 2 US healthcare systems (2017-2019).
• Prevalence and trends of vancomycin DALs were determined.
• Natural language processing (NLP) was used to classify HSR phenotypes from structured and unstructured data.
• Demographic associations with red man syndrome (RMS) documentation were investigated.

Main Results:

• Over 4.4 million patients, 0.3% had a vancomycin DAL, with 12% of reactions documented in free-text.
• Rash (32%) and RMS (16%) were the most common HSRs; anaphylaxis was coded in 6% of cases.
• RMS documentation varied by demographics, being more likely in males and less likely in Black patients.

Conclusions:

• Vancomycin triggers various HSRs, including common ones like RMS and severe reactions like DRESS, often recorded as free-text entries.
• While anaphylaxis is coded in 6% of HSRs, true IgE-mediated reactions are rare.
• Enhanced EHR documentation, particularly coded options for RMS, is crucial for precise vancomycin HSR management.