List of products in the National Drug Code with proprietary name . This medication is used in certain people to treat outbreaks of herpes simplex infection of the skin (such as on the genitals), mucous membrane areas (such as the mouth, nose), or brain. It is also used in certain people to treat shingles infection. The viruses that cause these infections live in the body quietly until an outbreak occurs. Acyclovir does not cure these infections, but can speed healing of the sores, decrease pain/itching/formation of new sores, and lower the risk of other problems from the virus (e.g., infection spreading to other parts of the body/organs, persistent pain after sores heal).