What is Valacyclovir? Valacyclovir may be found in some form under the following brand names: Valtrex. Valacyclovir is a prescription medication used to treat conditions caused by the herpes virus including cold sores, shingles, genital herpes outbreaks, and chicken pox. Valacyclovir belongs to a group of drugs called antivirals which work by preventing the virus from multiplying.
Valacyclovir precautions. Before taking valacyclovir, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.