BACKGROUND:

It is common practice to administer acyclovir as prophylaxis to patients with hematologic malignancies during neutropenia; however, effective therapy requires frequent dosing, which is difficult in this setting. Valacyclovir has greater oral bioavailability and requires less frequent dosing.

OBJECTIVE:

To evaluate the efficacy and safety of valacyclovir compared with acyclovir.

METHODS:

Patients who had been treated with chemotherapy or stem-cell transplantation were randomized to receive acyclovir 400 mg orally 3 times daily (n = 51), valacyclovir 500 mg orally twice daily (n = 48), or valacyclovir 250 mg orally twice daily (n = 52) during neutropenia.

RESULTS:

Clinical success, defined as the absence of an active herpes simplex virus (HSV) lesion or asymptomatic viral shedding, was similar between the 3 groups (acyclovir 96%, valacyclovir 500 mg 95%, valacyclovir 250 mg 100%). The overall rates of adverse events were similar in the 3 groups.

CONCLUSIONS:

Prophylactic treatment with valacyclovir is an effective and safe alternative to acyclovir for the prevention of HSV reactivation in patients with hematologic malignancies.