What is a major side effect of flucytosine?

Flucytosine is known for its potential to cause bone marrow suppression, which is a significant concern when using this antifungal agent. This side effect arises because flucytosine gets converted to 5-fluorouracil in the body, which interferes with the synthesis of DNA and RNA in rapidly dividing cells, including those in the bone marrow. As a result, patients may experience leukopenia (decreased white blood cell count), thrombocytopenia (decreased platelet count), or anemia (decreased red blood cell count), leading to increased risk of infections, bleeding, and fatigue.

While other side effects such as hepatotoxicity, nausea, and vomiting can occur with various medications, the distinctive and critical impact of flucytosine on bone marrow function highlights why it is essential for healthcare providers to monitor blood counts in patients undergoing treatment with this drug. Cardiotoxicity is not a commonly associated side effect of flucytosine and is generally more related to other medications. Thus, recognizing bone marrow suppression as a major side effect underscores the importance of regular blood monitoring during flucytosine therapy.