Docosanol (Abreva) is a long-chain saturated alcohol that is clinically effective against HSV. It has in vitro ac-tivity against many enveloped viruses, including CMV, influenzavirus, and respiratory syncytial virus.
Docosanol is not directly virucidal; instead, it blocks the entry of the virion into the host cell by inhibiting the fusion of the viral envelope with the host plasma mem-brane. Because it does not affect viral replication or pro-tein production, it may be less susceptible to the develop-ment of resistance than other antiviral drugs.
Docosanol is topically applied; systemic absorption is minimal.
Docosanol cream is approved for the over-the-counter treatment of herpes labialis. It shortens the duration of symptoms of cold sores and fever blisters but does not provide symptomatic relief.
Adverse effects of docosanol are minimal. Skin irrita-tion occurs infrequently. Drug interactions are not an-ticipated.