Which medication is specifically used for treating herpes labialis?

Penciclovir is specifically indicated for topical treatment of herpes labialis, commonly known as cold sores. This medication works by inhibiting the replication of the herpes simplex virus, thereby reducing the duration and severity of symptoms when applied at the early stages of an outbreak. Penciclovir is designed for local application, which allows it to target the infected area effectively.

While acyclovir and valacyclovir are antiviral medications used to treat herpes infections, they are often prescribed for systemic treatment of more serious herpes simplex infections, including those affecting other parts of the body or for prophylactic use. Oseltamivir, on the other hand, is an antiviral medication used specifically for influenza and does not have an effect on herpes viruses.

Thus, the choice of penciclovir is appropriate for directly addressing cold sores, given its specific formulation and mechanism of action aimed at treating herpes labialis.