Antiviral Agents: Ganciclovir/Valganciclovir

Ganciclovir was the first antiviral drug noted to have activity against cytomegalovirus (CMV). It has an oral analog, valganciclovir, an L-valine ester of ganciclovir that improves oral bioavailability substantially and allows for equivalent exposure through the oral route. Ganciclovir and valganciclovir display broad anti-herpesvirus activity and represent common options utilized to treat CMV and HHV-6. Both require phosphorylation to an active form inside the virus, with the activated form inhibiting viral DNA polymerase.