Valacyclovir is an antiviral drug. It slows the growth and spread of the herpes virus to help the body fight the infection. Valacyclovir is used to treat infections caused by herpes viruses, including genital herpes, cold sores, and shingles (herpes zoster) in adults. Valtrex (valacyclovir) is a prescription medication used to treat viral infections such as genital herpes, cold sores (fever blisters), and shingles. Valtrex dosages depend on what you’re taking it for, your age, and if you have kidney problems. Valacyclovir is used to treat cold sores (herpes labialis), shingles (herpes zoster), and genital herpes. It is also used to control genital herpes outbreak in patients with human immunodeficiency virus-1 (HIV-1). This medicine is also used to treat cold sores and chickenpox in children. Valtrex (Valacyclovir Hydrochloride) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. It is marketed by GlaxoSmithKline under the brand names Valtrex [1] and Zelitrex. Valaciclovir has been available as a generic drug in the US since November 2009. Find patient medical information for Valacyclovir (Valtrex) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Valtrex is an antiviral drug. It slows the growth and spread of the herpes virus to help the body fight the infection. Valtrex is used to treat infections caused by herpes viruses, including genital herpes, cold sores, and shingles (herpes zoster) in adults. Valtrex (valacyclovir) is an antiviral medication to treat certain viral infections, including cold sores, genital herpes, and shingles. Herpes Zoster: VALTREX is indicated for the treatment of herpes zoster (shingles) in immunocompetent adults. The efficacy of VALTREX when initiated more than 72 hours after the onset of rash. Medscape - Herpes simplex, zoster-specific dosing for Valtrex (valacyclovir), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and.