Valtrex (Valacyclovir Hydrochloride) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. 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. 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. Valacyclovir comes as a tablet to take by mouth with or without food. It is 1 to 3 times a day depending on the condition being treated. Take valacyclovir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Use this medication as soon as possible after symptoms appear. 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 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. Find patient medical information for Valacyclovir (Valtrex) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Valtrex is a nucleoside analogue DNA polymerase inhibitor used for the treatment of viruses including cold sores, genital herpes, shingles and chickenpox. 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. Valacyclovir (Valtrex) is an antiviral medication used for treating infections caused by herpes simplex virus and varicella zoster virus, such as cold sores, genital herpes, and shingles, and chickenpox.