Aciclovir desensitisation and rechallenge

A case of successful acyclovir desensitization in a bone marrow transplant patient

INTRODUCTION

The incidence of acyclovir-induced hypersensitivity is rare. To our knowledge, there are four published case reports of oral acyclovir desensitization in adults. Evidence-based guidelines prompt the use of acyclovir for herpes simplex virus (HSV) prophylaxis and treatment. Literature on the cross-reactivity of structurally similar antiviral agents is conflicting, presenting a clinical challenge when choosing an alternative agent. This is a case of successful acyclovir desensitization in an allogeneic stem cell transplant patient.

CASE REPORT

A 69-year-old female patient, diagnosed with myelodysplastic/myeloproliferative neoplasm, presented to the hospital for donor mismatch allogeneic bone marrow transplant. The patient reported acyclovir-induced angioedema while receiving treatment for non-complicated herpes zoster (shingles) infection.Management & Outcome: After the acyclovir oral desensitization was conducted in an ICU setting with 1:1 patient-nurse ratio, the patient was successfully started on acyclovir therapy, 800mg by mouth twice daily for HSV prophylaxis with no further complications. Discussion: Oral acyclovir desensitization can provide an option for HSV therapy in patients reporting severe allergy.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Recurrent Body Rash Warranted Second Desensitization With Acyclovir in a Myeloma Patient: A Case Report

A 75-year-old woman developed a moderately severe rash about a week and a half after the start of bortezomib (Btb)-based chemotherapy for IgG lambda multiple myeloma; at the time, she was also receiving acyclovir as antiviral prophylaxis in addition to herpes zoster (HZ) vaccination. HZ reactivation rate is high in Btb recipients; therefore, the timing of antiviral prevention is critical in relation to Btb. Attempts were made to identify the offending agent based on the timing of drugs administered and the appearance of skin lesions in relation to other drugs. Both Btb and acyclovir were potential culprits. However, the timing of rash presented on days 9 - 10 revealed the offending agent when the corticosteroid was weaned off while acyclovir continued. A decision was made to administer acyclovir rapid desensitization program (RDP) for our patient.