Article: FDA Updates Labeling of Valtrex

The Food and Drug Administration (FDA) has approved a new indication for Valtrex (valacyclovir hydrochloride) Caplets; Valtrex reduces the risk of heterosexual transmission of genital herpes to susceptible partners with healthy immune systems when used as suppressive therapy in combination with safer sex practices.

Genital herpes is a common sexually transmitted infection caused by herpes simplex viruses (HSV). Many individuals have no or only minimal signs or symptoms from genital HSV infection and may transmit the virus during sexual contact when they show no signs of active infection (i.e. genital lesions).

The following safer sex practices can also lower the chances of passing genital herpes to a partner:

• Use a condom made of latex or polyurethane when you have sexual contact.
• Do not have sexual contact with your partner when you have any symptom or outbreak of genital herpes.

FDA based its decision to revise the labeling for Valtrex on the results of an international, double-blind, placebo-controlled clinical trial conducted by the manufacturer, GlaxoSmithKline (GSK) of Research Triangle Park, N.C. The study was conducted among about 1500 monogamous, heterosexual couples and lasted eight months. At the beginning of the study, only one member in each couple had evidence of genital herpes. The results of the GSK study showed a 48% reduction in HSV acquisition; individual results may vary based on consistency of safer sex practices.

Valtrex may cause kidney problems in some people. In addition, Valtrex may cause nervous system problems; these include aggressive behavior, unsteady movements, shaky movements, confusion, speech problems, hallucinations, seizures and coma. Kidney and nervous system problems have happened in patients who already have kidney disease and in elderly patients whose kidneys do not work well due to age. Therefore, it is important for patients to tell their healthcare providers if they have kidney problems or other medical conditions before taking Valtrex.

Today’s action follows the recommendation of FDA’s Antiviral Drugs Advisory Committee, which met on May 14, 2003, to discuss GSK’s then-proposed use of Valtrex for reduction of the risk of transmission of genital herpes with the use of suppressive therapy. FDA first approved Valtrex in 1995.