Which adverse effect requires monitoring with ganciclovir?

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

Answer: (D)

Bone marrow suppression is the adverse effect to monitor with ganciclovir. This antiviral can affect rapidly dividing cells, including bone marrow precursors, leading to neutropenia, anemia, and thrombocytopenia. Because these cytopenias raise infection risk and can cause bleeding or fatigue, regular blood count monitoring is essential. Start with a baseline CBC before therapy and check counts regularly during treatment (often weekly or per protocol), adjusting the dose or stopping treatment if counts drop significantly. Monitoring renal function is also important since ganciclovir is excreted renally and may require dose adjustments in kidney impairment. Other listed adverse effects are not the primary toxicities that drive the need for routine hematologic monitoring.