Data from an initial four-month trial suggests that daily use of the antiviral agent Valtrex(R) (valacyclovir HCl) Caplets in patients prone to cold sores may significantly reduce the chances of recurrent bouts of the disease. These new data were presented yesterday at the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).
"Cold sores are a very common and very troubling condition for patients that result in repeated bouts of blisters or sores on the face and mouth," explains David A. Baker, M.D., State University of New York in Stony Brook the lead investigator of the study. "Effective antiviral treatment is greatly needed given the limitations of current treatment options and the impact cold sores have on the appearance of many patients. These new data warrant further study of Valtrex for potential use in the medical management of herpes labialis in the future."
These new findings come from an initial four-month double blind,
placebo-controlled study that investigated the effect of Valtrex in reducing
recurrent herpes labialis outbreaks. The clinical trial involved a total of
95 men and women who had a history of four or more episodes of cold sores per year. Patients received Valtrex (500 mg.) or placebo once a day for four months. If a patient experienced an outbreak during the study, they switched from taking the study medication to taking a 5-day course of Valtrex (500 mg. twice-daily open label) and then restarted the study medication once the cold sore crusted.
At the completion of the study, there were significantly fewer cold sore outbreaks in the group treated with Valtrex versus the placebo recipients. Sixty percent (28/47) of patients receiving Valtrex were recurrence free at four months compared to only 38 percent (18/48) of those receiving placebo. Furthermore, patients who took Valtrex were recurrence-free longer than those who took placebo. The time to first recurrence was approximately 13.1 weeks among the patients receiving Valtrex versus 9.1 weeks for the placebo group.
In this study, Valtrex was also well tolerated. Adverse events attributed to Valtrex were low and included headache (1 patient) and constipation (1 patient).
Cold sores, medically known as herpes labialis, are a common viral illness affecting 20 million Americans each year. The condition is caused by the herpes simplex virus (HSV) type I. On contracting the virus, patients experience what is called a 'primary infection', or 'first episode.' Following this first episode, the virus goes into a latent stage and becomes inactive. The virus periodically reactivates. These recurrent episodes are common and vary in frequency, ranging from one to more than six outbreaks a year, depending on the individual.
This new two-center study is the first to examine the potential usefulness of Valtrex in the suppression of herpes labialis. While Valtrex has been shown to be effective in suppressing genital herpes outbreaks, its effect on cold sores must be established through well-controlled clinical trials.
Valtrex is currently under investigation for the treatment of herpes labialis. To determine the efficacy of suppressive therapy with Valtrex in people with cold sores, additional studies are needed.
Valtrex is currently indicated for the treatment and suppression of
recurrent genital herpes.