Snapshot A 56-year-old man with a history of HIV presents to the emergency room with fevers, headaches, and general malaise. A head CT shows soap bubble lesions and variable enhancing lesions, concerning for Cryptococcus. A lumbar puncture and subsequent India ink stain on cerebral spinal fluid show yeast with clear halos, confirming the diagnosis. He is admitted immediately and started on dual anti-fungal therapy. (Cryptococcal meningitis) Introduction Drugs flucytosine Mechanism of action the drug is converted to 5-fluorouracil and inhibits nucleic acid synthesis cleared renally Clinical use Cryptococcal infections used with amphotericin B systemic fungal infections candidal infections resistant to azoles Adverse effects bone marrow suppression gastrointestinal upset hallucinations renal failure use with caution in those with renal failure