Treatment of Trichosporon asahii Infection in Immunocompromised Patients
Voriconazole is the drug of choice for Trichosporon asahii infection in neutropenic patients, with a recommended dosing of 6 mg/kg IV every 12 hours for two doses, followed by 4 mg/kg IV every 12 hours (or 200-300 mg orally twice daily after clinical stabilization). 1, 2, 3
Primary Treatment Recommendation
Voriconazole demonstrates superior in vitro activity against T. asahii compared to all other triazoles, with MIC-0 values of 0.5 μg/ml and MFC values of 2 μg/ml at 48 hours, significantly better than fluconazole, itraconazole, posaconazole, or isavuconazole 2
Multiple case reports and epidemiological studies confirm voriconazole as the primary drug of choice, with successful outcomes in disseminated T. asahii infections in immunocompromised hosts including transplant recipients and neutropenic patients 1, 3, 4
Early initiation of voriconazole is critical, as mortality from T. asahii can reach 80% despite treatment, but early appropriate antifungal therapy significantly improves survival 4
Alternative and Combination Therapy
Amphotericin B lipid formulation (3-5 mg/kg daily) is a reasonable alternative if voriconazole cannot be used, though it frequently displays inadequate fungicidal activity against T. asahii 2, 5
Combination therapy with amphotericin B plus voriconazole does NOT show superiority over either drug alone and is not recommended as routine therapy 1
The combination of caspofungin plus amphotericin B demonstrates 89% synergistic effects in vitro, which may be considered in refractory cases, though clinical data are limited 5
Echinocandins alone have no meaningful antifungal effect against Trichosporon and should not be used as monotherapy 2
Critical Dosing Considerations
For voriconazole IV: Loading dose of 6 mg/kg every 12 hours for 2 doses, then maintenance of 4 mg/kg every 12 hours 3
For oral voriconazole step-down: 200-300 mg twice daily after clinical stabilization 3
Important drug interaction: Voriconazole significantly increases tacrolimus levels in transplant recipients—reduce tacrolimus dose to approximately one-third when initiating voriconazole 3
Duration and Monitoring
Continue treatment for at least 2 weeks after documented clearance of fungemia and resolution of neutropenia 1, 4
Blood cultures should be repeated every 1-2 days to establish clearance of T. asahii from bloodstream 1
Monitor voriconazole levels if available, particularly in patients with suboptimal clinical response 3
Key Risk Factors to Address
Remove central venous catheters when feasible, as invasive medical equipment is a leading risk factor for T. asahii infection 1
Antibiotic use and chemotherapy are major predisposing factors in neutropenic patients 1
Blood disorders and immunodeficiency are the most common underlying conditions 1
Common Pitfalls to Avoid
Do not delay switching from amphotericin B to voriconazole if there is lack of clinical or microbiological response within 3-5 days 3
Do not use fluconazole as first-line therapy—it has the poorest activity among triazoles with MIC-0 values of 32 μg/ml, far exceeding achievable serum concentrations 2
Do not assume fungicidal activity from azoles—all triazoles display fungistatic rather than fungicidal activity against T. asahii, emphasizing the need for immune reconstitution 2