The widely used genital herpes drug Valtrex (valacyclovir) can now be advertised as helping to prevent the spread of herpes simplex virus type 2, the Food and Drug Administration ruled Friday. Until now, the only advice for not transmitting genital herpes has been to use condoms and avoid sexual contact during the infection's periodic flare-ups, when lesions appear. But condoms do not always cover all the sores, and the virus sometimes can be transmitted when there are no visible lesions.
Valtrex treats herpes flare-ups by suppressing the virus. A recent study tracked whether that suppression would be enough to also protect an infected person's sexual partner. Researchers enrolled almost 1,500 couples in which one partner had herpes and the other partner did not, and gave the infected partners either a once-daily Valtrex or a placebo. Valtrex use cut in half the healthy partner's risk of becoming infected. Based on that study, the FDA ruled that manufacturer GlaxoSmithKline now can advertise Valtrex to reduce the risk of spreading herpes when used in combination with safer sex practices--condom use and abstinence during outbreaks.