Blood cultures from a febrile neutropenic patient grow a yeast identified as Candida krusei. The patient had been receiving fluconazole prophylaxis. What is the most appropriate next step in antifungal therapy?
- A Switch to an echinocandin such as caspofungin ✓
- B Increase the dose of fluconazole
- C Add flucytosine to continuing fluconazole
- D Continue fluconazole and add topical nystatin
Correct answer: A. Switch to an echinocandin such as caspofungin
Explanation
Candida krusei is intrinsically resistant to fluconazole through reduced target sensitivity of lanosterol 14-alpha-demethylase, and breakthrough C. krusei fungaemia during fluconazole prophylaxis is well described. Echinocandins such as caspofungin, micafungin, and anidulafungin inhibit beta-glucan synthesis and are active against C. krusei, making them the preferred choice. Raising the fluconazole dose will not overcome intrinsic resistance, flucytosine is not combined with fluconazole for candidemia, and topical nystatin is irrelevant for bloodstream infection.
Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.