Efficacy of Interferon and Placebo in the Treatment of Recurrent Genital Herpes: A Double-blind Trial

One hundred patients experiencing recurrence of genital herpes were randomly assigned to treatment with either recombinant DNA-derived human leukocyte interferon (interferon alfa-2a, Roferon-A®, Hoffmann-LaRoche & Co., Ltd.) or placebo in a double-blind study. All patients were given a three-day course of treatment by subcutaneous injection within 24 hr after the first signs of recurrence. Interferon alfa-2a was given according to one of two daily regimens (6 × 10⁶ or 18 × 10⁶ units), either as a single dose followed by two doses of placebo or as three consecutive doses. In comparison with placebo, interferon alfa2a reduced the duration of a single recurrent episode of genital herpes by ~50% (P < .05) compared with placebo. As compared with pretreatment episodes, a reduction of >50% in healing time was observed in 81% of those receiving interferon alfa-2a in comparison with only 10% of placebo recipients. Response was not related to size of dose, and treatment did not significantly prolong the interval between the first and second recurrences. No serious adverse reactions were observed, but most patients developed flu-like symptoms after the subcutaneous injection. Leukopenia and thrombocytopenia were minimal and transient. On the basis of overall efficacy and adverse effects, the single dose of 6 × 10⁶ units of interferon alfa-2a was considered optimal, and this regimen may be of value in the routine treatment of recurrent herpes.