The efficacy of valacyclovir in preventing recurrent herpes simplex virus infections associated with dental procedures

ABSTRACT Background Oral herpes simplex virus, or HSV, infections recur after trauma and stress. The prevalence of these infections after dental procedures is not known. Also, it is unclear whether antiviral agents are effective in preventing dental procedure–induced HSV recurrences. This study determined the efficacy and safety of oral valacyclovir in suppressing dentally related cold sore outbreak and HSV shedding. Methods The authors enrolled 125 otherwise healthy HSV-seropositive adults who reported having recurrent herpes labialis (more than one episode per year and at least one episode in the previous year) in a randomized, double-blind, placebo-controlled study and gave them valacyclovir prophylactically (2 grams taken twice on the day of dental treatment and 1 g taken twice the next day) or a matching placebo. To detect the presence of the virus, the authors used clinical examinations, viral cultures and real-time polymerase chain reaction analysis of saliva. Results During the one-week observation period after treatment, there were more clinical lesions (20.6 percent versus 11.3 percent), more HSV-1–positive culture specimens (7.9 percent versus 1.6 percent) and more HSV-1–positive saliva specimens (7.9 percent versus 4.0 percent) in placebo than in valacyclovir-treated patients, respectively. The percentage of patients who developed recurrences and shed HSV-1 in saliva 72 hours after dental procedures was significantly smaller in the valacyclovir group than in the placebo group (11.3 percent versus 27 percent; P = .026). The mean time to pain cessation was significantly less in the valacyclovir group (3.2 days) than in the placebo group (6.2 days) ( P = .006). Conclusion HSV recrudescence after routine dental treatment is suppressed by valacyclovir prophylaxis. Clinical Implications HSV recrudescence is common after routine dental treatment. Clinicians should consider antiviral therapy for patients at risk of experiencing a recurrence, as well as to minimize transmission of the disease.