From the Guidelines
Treatment of yeast blood cultures requires prompt initiation of antifungal therapy with an echinocandin, such as caspofungin (70 mg loading dose, then 50 mg daily), micafungin (100 mg daily), or anidulafungin (200 mg loading dose, then 100 mg daily), as the first-line treatment. These medications should be administered intravenously for at least 2 weeks after documented clearance of Candida from the bloodstream, provided neutropenia and symptoms attributable to candidemia have resolved 1.
Key Considerations
- For stable patients with Candida albicans or other susceptible species, fluconazole (800 mg loading dose, then 400 mg daily) may be used as an alternative 1.
- All intravascular catheters should be removed if possible, as they can serve as a nidus for infection 1.
- Blood cultures should be repeated daily until negative to ensure clearance of the infection.
- Ophthalmologic examination is recommended to rule out endophthalmitis, and should be performed within the first week after recovery from neutropenia 1.
- For patients with persistent candidemia, evaluation for metastatic foci of infection including endocarditis or osteomyelitis should be performed.
Preferred Treatment
Echinocandins are preferred initially because they have fungicidal activity against most Candida species and have fewer drug interactions compared to azoles 1.
Step-Down Therapy
Step-down therapy to oral fluconazole can be considered after clinical improvement if the isolate is susceptible and the patient can tolerate oral medications 1.
Special Considerations
- For infections due to C. krusei, an echinocandin, lipid formulation AmB, or voriconazole is recommended 1.
- Granulocyte colony-stimulating factor (G-CSF)–mobilized granulocyte transfusions can be considered in cases of persistent candidemia with anticipated protracted neutropenia 1.
From the FDA Drug Label
Two dose levels of micafungin for injection were evaluated in a randomized, double-blind study to determine the efficacy and safety versus caspofungin in patients with invasive candidiasis and candidemia Patients were randomized to receive once daily intravenous infusions (IV) of micafungin for injection, either 100 mg/day or 150 mg/day or caspofungin (70 mg loading dose followed by 50 mg maintenance dose) Outcome was assessed by overall treatment success based on clinical (complete resolution or improvement in attributable signs and symptoms and radiographic abnormalities of the Candida infection and no additional antifungal therapy) and mycological (eradication or presumed eradication) response at the end of IV therapy.
The treatment for yeast blood cultures, specifically candidemia, involves the use of antifungal medications such as micafungin. The recommended dose of micafungin for injection is 100 mg/day.
- The treatment success rate for micafungin at this dose was 70.7% in patients with candidemia and other Candida infections.
- Success rates varied by Candida species, with the highest success rate seen in patients with C. parapsilosis (75%).
- Patients with Candida endocarditis were excluded from the analysis.
- The treatment regimen may involve switching to oral fluconazole after at least 10 days of intravenous therapy, provided certain conditions are met, such as the patient being non-neutropenic and having a Candida isolate susceptible to fluconazole 2.
Alternatively, voriconazole can be used to treat candidemia, with a response rate of 41% in non-neutropenic patients, comparable to the regimen of amphotericin B followed by fluconazole 3.
- The success rate varied by Candida species, with the highest success rate seen in patients with C. parapsilosis (53%).
- Voriconazole was also evaluated in patients with deep tissue Candida infections, with favorable responses seen in some patients with intra-abdominal, kidney and bladder wall, and deep tissue abscess or wound infections 3.
From the Research
Treatment of Yeast Blood Cultures
- The treatment of yeast blood cultures involves the use of antifungal agents, with the choice of agent depending on the species of Candida identified 4.
- A study published in 2009 investigated the in vitro antifungal combination effects of micafungin with fluconazole, voriconazole, amphotericin B, and flucytosine against clinical isolates of Candida species, and found that the synergistic antifungal effects of micafungin-fluconazole and micafungin-voriconazole were 11% and 15%, respectively 5.
- Another study published in 2020 found that elevated minimum inhibitory concentrations to antifungal drugs prevail in 14 rare species of candidemia-causing Saccharomycotina yeasts, and that amphotericin B had the broadest efficiency against the 14 tested rare yeast species, while high minimum inhibitory concentrations against azole drugs and echinocandins were common 6.
Antifungal Agents
- The echinocandins, including caspofungin, micafungin, and anidulafungin, are a class of antifungal agents that exhibit high in vitro and in vivo activities against Candida spp. and Aspergillus spp. 7.
- These agents can be used as salvage therapy in life-threatening fungal infections, and have excellent safety and tolerability profiles 7.
- The use of serological tests, such as the Platelia Candida Antigen and Antibody tests, can contribute to the early diagnosis of systemic candidiasis, and can be used in conjunction with blood cultures to initiate antifungal therapy earlier 8.
Diagnosis and Management
- The isolation of Candida species from a single blood culture is considered sufficient evidence for the initiation of systemic antifungal therapy 8.
- However, blood cultures still lack sensitivity, and the use of serological tests and other diagnostic methods can help to improve the diagnosis and management of systemic candidiasis 8.
- A rapid identification of Candida species in blood cultures is critical for the implementation of appropriately targeted antifungal drug therapy, and can be achieved using PCR-based assays 4.