A client with cytomegalovirus (CMV) is to start on ganciclovir (Cytovene) for retinitis. The nurse should carefully monitor for which adverse effect?

• A. Tinnitus
• B. Inflammation of the gallbladder
• C. Bone marrow depression
• D. Myalgia and muscle weakness

Answer: (C)

The main concept here is that ganciclovir commonly causes bone marrow suppression. This antiviral can significantly lower white blood cell, red blood cell, and platelet counts, leading to neutropenia, anemia, and thrombocytopenia. For a patient starting therapy for CMV retinitis, the nurse must monitor the complete blood count regularly to detect these cytopenias early. Neutropenia raises infection risk, thrombocytopenia increases bleeding risk, and anemia can cause fatigue and dyspnea—problems that are especially serious in someone with active CMV infection and often compromised immunity. That’s why bone marrow depression is the key adverse effect to watch for and manage, guiding dose adjustments and treatment plans. Tinnitus, gallbladder inflammation, and myalgia are not the primary concerns with ganciclovir, so they are not the focus of routine monitoring.