What is the treatment for Candida lusitaniae infections?

Treatment of Candida lusitaniae Infections

Fluconazole is the preferred first-line therapy for Candida lusitaniae infections due to the well-documented resistance of this species to amphotericin B. 1

Antifungal Options for C. lusitaniae

First-line therapy:

• Fluconazole 6 mg/kg daily (standard adult dose) is the preferred treatment for C. lusitaniae infections due to its effectiveness against this species and the known resistance patterns 1
• For severe infections, consider starting with fluconazole 12 mg/kg daily (800 mg/day for a 70-kg patient) to ensure adequate drug levels 1

Alternative options:

• Echinocandins (caspofungin, micafungin, or anidulafungin) are effective alternatives when fluconazole cannot be used or in critically ill patients 1, 2
• Voriconazole has activity against C. lusitaniae and can be considered as an alternative therapy 3, 1
• Lipid formulation amphotericin B should be used with extreme caution due to the high likelihood of resistance 1

Special Considerations

Resistance patterns:

• C. lusitaniae is well-known for its ability to rapidly develop resistance to amphotericin B, which is a unique characteristic of this species 1, 4
• Not all C. lusitaniae isolates are resistant to amphotericin B, but resistance is common enough that amphotericin B should not be used as first-line therapy 1
• Multidrug resistance can emerge during therapy, particularly when sequential or combination antifungal treatments are used 5, 6

Susceptibility testing:

• Antifungal susceptibility testing is strongly recommended for all C. lusitaniae isolates due to variable resistance patterns 4, 7
• Treatment should be adjusted based on susceptibility results to ensure optimal therapy 2, 7

Treatment duration:

• For candidemia without metastatic complications, treat for 14 days after documented clearance of Candida from the bloodstream and resolution of symptoms 1
• For deep-seated infections, longer treatment courses may be necessary until all signs, symptoms, and radiological abnormalities have resolved 1

Source control:

• Removal of infected central venous catheters is strongly recommended for candidemia 1, 2
• For intra-abdominal infections, appropriate drainage and/or debridement is essential 1

Treatment Algorithm

1. Obtain cultures and initiate empiric therapy with fluconazole 6-12 mg/kg daily 1
2. For critically ill patients, consider starting with an echinocandin (caspofungin: 70-mg loading dose, then 50 mg daily; anidulafungin: 200-mg loading dose, then 100 mg daily; or micafungin: 100 mg daily) 1
3. Perform susceptibility testing on all isolates 4, 7
4. Adjust therapy based on susceptibility results and clinical response 1, 2
5. Continue treatment for at least 14 days after clearance of infection and resolution of symptoms 1
6. Monitor for development of resistance, especially if clinical response is poor 5, 6

Pediatric Considerations

• In neonates with disseminated candidiasis, fluconazole 12 mg/kg daily is recommended if C. lusitaniae is isolated 1
• For severe neonatal infections, consider starting with fluconazole rather than amphotericin B due to the risk of resistance 1, 5
• Echinocandins should be used with caution in neonates and generally limited to salvage therapy 1

Common Pitfalls and Caveats

• Assuming all Candida species have similar susceptibility patterns can lead to treatment failure with C. lusitaniae 1
• Failure to perform susceptibility testing may result in continued use of ineffective therapy 4, 7
• Colony morphology switching can affect susceptibility to antifungals and should be monitored during treatment 5
• Breakthrough infections can occur during treatment with amphotericin B due to resistance 2
• Sequential therapy with different antifungal classes may promote the development of multidrug resistance 6