Herpes, Valtrex
Valacyclovir Suppressive Therapy Reduces HSV-2 Transmission
Peggy Peck;
Medscape Medical News 2003. © 2003 Medscape
March 25, 2003 (San Francisco) — Final analysis of a multicenter study of 1,484 herpes simplex virus 2 (HSV-2)–discordant couples indicates that chronic valacyclovir suppressive therapy can reduce the rate of clinical transmission by 77% and cut seroconversion by 50%, according to research presented here Monday at the 61st annual meeting of the American Academy of Dermatology.
Gisela Torres, MD, from the University of Texas Medical Branch Center for Clinical Studies in Galveston, said, “This is the first time that antiviral therapy has demonstrated the ability to prevent or reduce transmission of a virus.”
Of placebo-treated couples, 3.8% converted compared with 1.9% of the couples randomized to receive valacyclovir. However, among the 14 valacyclovir-treated couples who converted, “eight of those had less than 95% compliance with study treatment. Only six partners whose partners were at least 95% compliant converted,” Dr. Torres said.
Transmission also increased with sexual activity, with the transmission risk lowest among couples who reported intercourse no more than five times a month, she said. “Risk increases in a linear fashion with the greatest increase occurring in couples who reported intercourse more than 10 times a month. But even in this group, valacyclovir was protective.”
Risk was also inversely associated with condom use, but Dr. Torres told Medscape that the study did not examine the relationship between condom use and frequency of sexual contact.
In addition to a demonstrated reduction in transmission, “antiviral suppression therapy also reduced recurrences,” said Dr. Torres. Sixty percent of the valacyclovir-treated patients reported no recurrences during eight months of active treatment. During this same period, 20% of the placebo-treated infected partners reported recurrences.
Seven hundred and forty-three couples were randomized to 500 mg valacyclovir for the infected partners. In both the active treatment and placebo groups, couples were involved in monogamous relationships for an average of three years.
Peter Heald, MD, professor of dermatology at Yale-New Haven Hospital in Connecticut, said the results were impressive, but he questioned the safety of “a lifetime of valacyclovir treatment.”
Dr. Torres said that other studies demonstrate that antiviral therapy is “safe up to 10 years.”
Warren Heymann, MD, a dermatologist at Cooper Hospital/University Medical Center in Camden, New Jersey, who co-chaired the poster discussion with Dr. Heald, said “this treatment should be considered for all affected couples of child-bearing age.”
But the treatment is expensive: each pill costs $2 to $3. “Figure $1,000 a year for treatment,” said Dr. Torres’ coauthor Mathijis Brentjens, MD, also from the University of Texas Medical Branch. “But our experience is that insurers are willing to pay for the treatment, and even if coverage is denied, patients will pay for this protection.”
Dr. Torres said that other antiviral drugs such as acyclovir, which is given twice a day, and ganciclovir, may also be effective at reducing transmission risk.
The rate of herpes infection has been steadily increasing for the last 20 years, and she said the current estimate is that 45 million Americans are infected. Thus, the public health implications of this research are significant, especially the impact on prevention of maternal-fetal transmission.
“If the woman is the positive partner, she should be on antiviral therapy for the last trimester of her pregnancy so that she reduces the risk for viral shedding during delivery. If the woman is the uninfected partner, we would advise the couple to begin suppressive therapy before considering pregnancy,” said Dr. Torres.
The study was funded by GlaxoSmithKline.
AAD 61st Annual Meeting: Abstract P39. Presented March 24, 2003