It is primarily used as an antiviral agent, particularly in the treatment of herpesvirus infections. The compound works by inhibiting viral DNA synthesis, effectively reducing the replication of the virus in infected cells. It is often employed in the management of conditions such as herpes simplex virus (HSV) infections, including genital herpes and cold sores, as well as in the treatment of varicella-zoster virus (VZV) infections, such as shingles and chickenpox. Its mechanism of action involves phosphorylation by viral thymidine kinase, leading to the incorporation of its triphosphate form into viral DNA, which terminates DNA chain elongation. This makes it a valuable therapeutic option for controlling viral outbreaks and alleviating symptoms associated with these infections.