Acyclovir to Prevent Reactivation of Varicella Zoster Virus (Herpes Zoster) in Multiple Myeloma Patients Receiving Bortezomib Therapy

BACKGROUND: Humoral-mediated as well as cell-mediated immunity is compromised in myeloma patients receiving treatment. Immunocompromised patients are at risk of developing herpes zoster. There is evidence from clinical trials that bortezomib therapy is associated with a significant risk of herpes zoster. It is the authors' clinical policy to administer long-term acyclovir prophylactically to all symptomatic myeloma patients. METHODS: A retrospective review of the records of 125 myeloma patients who were treated with bortezomib and who also received routine acyclovir prophylaxis at the dose of 400 mg daily in >80% of patients was undertaken. Alternatives, used in <20% of patients, were 200 mg of acyclovir, 250/500 mg of valacyclovir, or 500 mg of famciclovir administered daily. This was accompanied by patient education regarding the importance of compliance with these prophylactic medications. RESULTS: The duration of bortezomib therapy was 1 to 164 weeks (median, 16 weeks). The total duration of exposure to bortezomib was 4150 weeks (80 patient-years). Except for the occasional missed dose, the self-reported compliance with antiviral prophylaxis was 100%. Not a single episode of herpes zoster was reported during this period. No adverse effects were noted that could be definitely attributed to acyclovir, valacyclovir, or famciclovir. CONCLUSIONS: Daily acyclovir (or a suitable alternative) appears to be effective at preventing herpes zoster virus in patients with myeloma who are receiving bortezomib, with or without corticosteroids. Cancer 2009;115:229-32. (C) 2008 American Cancer Society.