A 32-year-old man with HIV/AIDS (CD4 count 45 cells/µL) presents with a 3-week history of progressive headache, fever, and neck stiffness. CSF analysis shows: protein 180 mg/dL, glucose 35 mg/dL (serum glucose 95 mg/dL), WBC 120/µL (80% lymphocytes). India ink stain of CSF reveals budding yeast cells with a clear halo around them. What is the most appropriate initial antifungal therapy?

Explanation

## Diagnosis: Cryptococcal Meningitis ### Clinical Presentation The patient presents with classic features of cryptococcal meningitis in an advanced HIV patient: - CD4 < 100 cells/µL (highest risk) - Subacute meningitis (headache, fever, neck stiffness over 3 weeks) - CSF findings: elevated protein, low glucose with high CSF-to-serum glucose ratio - India ink stain positive: budding yeast with characteristic clear halo (capsule) ### Antifungal Management Algorithm ```mermaid flowchart TD A[Cryptococcal Meningitis Diagnosed]:::outcome --> B{Induction Phase}:::decision B -->|First-line| C["Amphotericin B deoxycholate<br/>0.7-1 mg/kg/day IV<br/>+/- Flucytosine 25 mg/kg QID"]:::action B -->|Alternative| D["Liposomal Amphotericin B<br/>if renal impairment"]:::action C --> E["2 weeks induction<br/>then assess CSF sterilization"]:::action E --> F[Consolidation Phase]:::decision F -->|Standard| G["Fluconazole 400-800 mg daily<br/>8 weeks consolidation"]:::action G --> H["Maintenance: Fluconazole<br/>200 mg daily until CD4 > 100 x 3 months"]:::action ``` ### Key Point: **Amphotericin B deoxycholate is the gold-standard induction agent for CNS cryptococcal infection.** It achieves superior CSF penetration compared to azoles and is essential for initial fungicidal therapy in meningitis. ### High-Yield: - **Induction (2 weeks):** Amphotericin B ± flucytosine - **Consolidation (8 weeks):** Fluconazole 400–800 mg daily - **Maintenance:** Fluconazole 200 mg daily until immune reconstitution (CD4 > 100 for ≥3 months) ### Clinical Pearl: **Flucytosine (5-FC) addition** during induction improves CSF sterilization and reduces mortality, especially when combined with amphotericin B. Monitor for bone marrow suppression and renal toxicity. ### Warning: ~~Fluconazole monotherapy is inadequate for meningitis~~ — it achieves only 50–90% CSF levels and lacks fungicidal activity. Reserved for consolidation/maintenance after induction with amphotericin B. ### Monitoring During Therapy - Repeat CSF culture at 2 weeks to confirm sterilization - Monitor renal function, electrolytes (hypokalemia, hypomagnesemia), and CBC - Assess immune reconstitution with CD4 recovery