What is the common use for the antiviral agent docosanol?

Docosanol is commonly used as a topical treatment for cold sores, which are caused by the herpes simplex virus. This antiviral agent works by inhibiting the fusion of the virus with host cell membranes, thereby preventing the virus from entering the cells and replicating. When applied at the first signs of a cold sore outbreak, docosanol can reduce the duration of symptoms and enhance healing.

In contrast, options suggesting intravenous therapy for respiratory syncytial virus (RSV), oral treatment for influenza, or preventive therapy for HIV do not align with the established clinical indications of docosanol. These uses require different classes of antiviral agents that are specifically formulated and proven effective for those viruses.