<unk>  is a guanosine analogue antiviral drug used for the treatment of various herpesvirus infections. It is a nucleoside analogue which exhibits low toxicity and good selectivity. Because<unk>  is absorbed poorly when given orally (by mouth) it is more often used as a topical treatment. It is the active ingredient in the cold sore medications Denavir (NDC 0135-0315-52), Vectavir and Fenivir. Famciclovir is a prodrug of<unk>  with improved oral bioavailability.<unk>  was approved for medical use in 1996.
Penciclovir
Aciclovir
Valganciclovir
Famciclovir
Ganciclovir
Alcaftadine
Letermovir
Amantadine