Herpes simplex virus (HSV) is one of Herpesviridae family viruses which belong to DNA viruses. HSV-associated diseases are among the most widespread infections, affecting nearly 60% to 95% of human adults. Labial herpes typically results from infection with HSV type 1 (HSV-1), whereas most genital herpes is caused by HSV type 2 (HSV-2). They are incurable and persist during the lifetime of the host, often in latent form. Antiviral agents do not cure HSV infections, but rather modify the clinical course of the disease. Topical, oral, or intravenous antiviral agents may be used in the management of HSV infections. Acyclovir, valacyclovir hydrochloride, and famciclovir are the 3 antiviral drugs commonly used to treat symptomatic HSV infections. However, it is very difficult to choose an appropriate drug and dosing regimen.