FoscarnetPhosphonoacetic AcidGanciclovirAntiviral AgentsCytomegalovirus RetinitisAcyclovirOrganophosphorus CompoundsCytomegalovirus InfectionsCytomegalovirusOrganophosphonatesSkin Diseases, ViralRetinitisCytosineStomatitis, HerpeticVirus ReplicationDrug Resistance, ViralHerpes LabialisAIDS-Related Opportunistic InfectionsHerpes SimplexAcquired Immunodeficiency SyndromeZidovudineAdministration, TopicalDNA-Directed DNA PolymeraseRoseolovirus InfectionsOintmentsReverse Transcriptase InhibitorsInterferonsDrug Resistance, MicrobialViral Plaque AssayHerpesvirus 6, Human