<unk>  is an antiviral agent that is FDA approved for the treatment of cytomegalovirus (CMV) retinitis; prevention of CMV disease in adults and children. There is a Black Box Warning for this drug as shown here.  Common adverse reactions include diarrhea, pyrexia, nausea, tremor, neutropenia, anemia, graft rejection, thrombocytopenia, hypertension, upper respiratory tract infection, cough, vomiting, constipation.
Valganciclovir hydrochloride
Ganciclovir 
Valacyclovir
Penciclovir
Tenofovir
Acyclovir 
Cidofovir
Letermovir