Antivirals for the treatment of herpesvirus infections

Agents available to treat herpesvirus infections include idoxuridine, trifluridine, vidarabine and acyclovir for the topical treatment of herpetic eye infections; vidarabine and acyclovir for the systemic (intravenous) treatment of herpes encephalitis; acyclovir for the topical and systemic (oral) treatment of genital herpes; acyclovir for the systemic (intravenous, oral) treatment of HSV or varicella-zoster (VZV) infections in immunosuppressed patients; brivudin for the systemic (oral) treatment of HSV-1 or VZV infections in immunosuppressed patients; and ganciclovir and foscarnet for the systemic (intravenous) treatment of cytomegalovirus (CMV) retinitis in AIDS patients. Brivudin is also effective in the treatment of herpetic eye infections that no longer respond to idoxuridine, trifluridine, vidarabine or acyclovir; and foscarnet is effective in the treatment of infections with acyclovir-resistant, thymidine kinase-deficient (TK-) HSV or VZV mutants. Other antiviral agents considered for use in herpesvirus infections include brovavir, penciclovir (and its prodrug famciclovir), desciclovir (a prodrug of acyclovir), bishydroxymethylcyclobutylguanine (BHCG) and, in particular, 1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC). The latter is more active than either acyclovir or ganciclovir in the chemotherapy and prophylaxis of various HSV-1, HSV-2, TK- HSV, VZV or CMV infections in animal models.