Background: Vancomycin anaphylaxis is a major management problem in patients with methicillin-resistant Staphylococcus aureus (MRSA) sepsis. Lerner et al in 1984 have described a protocol for desensitization to vancomycin; however, antibiotic blood levels have never been used as a guide in this process.
Case report: A 46-year-old female with ESRD on hemodialysis who developed a dialysis-catheter related MRSA sepsis was found to have anaphylaxis to vancomycin. She underwent successful desensitization to vancomycin using Lerner's protocol. Periodic antibiotic blood levels were used to guide the amount and frequency of vancomycin infusion to successfully maintain desensitization thereafter.
Discussion: Lerner described loss of desensitization to vancomycin when antibiotic infusion was stopped after 18 hours followed by successful desensitization to the same drug via the same protocol. This observation points out that desensitization to vancomycin appears to be dependent on some minimal drug level. In our case report, we have for the first time used the concept of blood levels to maintain successful desensitization to an antibiotic.
Conclusion: We hypothesize that desensitization to vancomycin can be induced and maintained by keeping a minimum antibiotic blood level. Further studies are needed to quantify this.