Purpose: Acyclovir and high doses of intramuscular leukocyte interferon have been shown to prevent dissemination of herpes zoster in cancer patients with localized herpes zoster. With the availability of recombinant interferon, we decided to conduct a multicenter, placebo-controlled, double-blind trial of intramuscular recombinant interferon alpha-2a to assess its efficacy and safety in the treatment of localized herpes zoster in immunosuppressed patients with cancer.
Patients and methods: Immunosuppressed cancer patients with localized herpes zoster were randomly assigned to receive placebo, 36 X 10(6) units of recombinant interferon alpha-2a per day, or 68 X 10(6) units of recombinant interferon alpha-2a per day. Due to frequent adverse effects, the 68 X 10(6) unit dose of interferon was discontinued prior to conclusion of the trial.
Results: Dissemination of herpes zoster occurred in 14 of the 24 patients (58 percent) who received placebo but in only four of 24 recipients (17 percent) of 36 X 10(6) units of interferon per day (p = 0.003). Adverse effects (fever, chills, headaches, gastrointestinal irritability, fatigue, and myalgias) were more common or severe in interferon-treated patients.
Conclusion: These results suggest that interferon modifies the severity of herpes zoster in immunosuppressed patients with cancer but is associated with frequent side effects.