Valganciclovir is an antiviral drug. It works by preventing viral cells from multiplying in your body. Valganciclovir treats cytomegalovirus (CMV) infection of the eye in adults with acquired immunodeficiency syndrome (AIDS). Valganciclovir also prevents CMV infection in adults and children who have received an organ transplant (heart, kidney, or kidney-pancreas). Valganciclovir will not cure CMV but it can help control the infection. Valganciclovir is not for treating CMV that a baby is born with. Valganciclovir may also be used for purposes other than those listed in this medication guide. Your doctor may have switched you from ganciclovir (Cytovene) to valganciclovir (Valcyte). The strength of these two medications is different. A valganciclovir tablet contains more medicine than a ganciclovir capsule. You may not need to use as many valganciclovir tablets as you did ganciclovir capsules. Take only the number of valganciclovir tablets your doctor has prescribed.