Caspofungin for Acremonium citrinum Infection in Immunocompromised Patients
Caspofungin is NOT recommended as first-line therapy for Acremonium citrinum infection; voriconazole combined with surgical debridement when feasible represents the optimal treatment approach for this rare hyalohyphomycosis.
Rationale for Treatment Selection
Why Not Caspofungin
Acremonium species demonstrate general resistance to echinocandins, including caspofungin, as these organisms are hyalohyphomycetes that do not respond reliably to agents targeting β-(1,3)-D-glucan synthesis 1.
The ESCMID/ECMM guidelines for hyalohyphomycosis specifically address Acremonium infections and do not recommend echinocandins as effective therapy for these organisms 1.
In vitro susceptibility studies show that Acremonium species are generally resistant to the most commonly used antifungal agents, with variable responses to amphotericin B and azoles, but no documented efficacy for echinocandins 2.
Recommended First-Line Approach
Voriconazole is the preferred antifungal agent for Acremonium infections in immunocompromised patients, based on clinical case reports demonstrating response after failure of amphotericin B 3.
Amphotericin B (preferably lipid formulations) remains an alternative first-line option, particularly when combined with surgical intervention 4.
Historical data from 1991 established that treatment requires a combination of surgical intervention when possible and amphotericin B, with azoles showing inhibitory activity 4.
Treatment Algorithm
Initial Management Steps
Obtain fungal cultures and species identification to confirm Acremonium and determine specific species, as susceptibility varies 1, 2.
Initiate voriconazole immediately while awaiting culture confirmation in immunocompromised patients with suspected hyalohyphomycosis 3.
Evaluate for surgical debridement of infected tissue, as this is critical for successful outcomes in localized infections 1, 4.
Antifungal Regimen
Voriconazole dosing: Loading dose of 6 mg/kg IV every 12 hours on day 1, followed by 4 mg/kg IV every 12 hours, with transition to oral therapy (200 mg twice daily for patients >40 kg) once stabilized 1.
Alternative: Lipid-based amphotericin B formulations at 3-5 mg/kg/day if voriconazole is contraindicated or unavailable 1, 4.
Consider combination therapy with voriconazole plus an echinocandin only in life-threatening infections, though evidence for Acremonium specifically is lacking 5.
Critical Adjunctive Measures
Reverse immunosuppression whenever possible, as immune reconstitution is the most important factor determining outcome 1.
Remove or replace central venous catheters if present, as these can serve as nidus for persistent infection 1.
Monitor voriconazole serum trough levels to optimize therapeutic efficacy and avoid toxicity, particularly given drug-drug interactions in immunocompromised patients 5.
Common Pitfalls and Caveats
Do not use fluconazole or itraconazole capsules, as Acremonium species show resistance to these agents in vitro 2.
Avoid caspofungin monotherapy despite its excellent safety profile and efficacy against Candida and Aspergillus, as it lacks activity against hyalohyphomycetes like Acremonium 1, 6.
Prolonged therapy is required (often weeks to months) until clinical and radiographic resolution, particularly in persistently immunosuppressed patients 1.
Susceptibility testing is recommended to guide therapy, though clinical correlation with in vitro results may be imperfect 2, 4.
Watch for treatment failure with amphotericin B alone, as clinical reports document cases requiring switch to voriconazole for response 3.