From the Guidelines
The treatment for disseminated blastomycosis typically involves a two-phase approach with antifungal medications, starting with liposomal amphotericin B at 3-5 mg/kg daily for 1-2 weeks, followed by oral itraconazole 200 mg twice daily for 6-12 months, as recommended by the Infectious Diseases Society of America 1.
Key Considerations
- For patients with mild to moderate disease who are not critically ill, treatment may begin directly with oral itraconazole 1.
- In severe cases, particularly those involving the central nervous system, higher doses of liposomal amphotericin B (5 mg/kg daily) are recommended for a longer initial period (4-6 weeks) before transitioning to itraconazole, which should be continued for at least 12 months 1.
- Alternative medications include voriconazole or posaconazole for patients who cannot tolerate itraconazole 1.
- During treatment, liver function tests should be monitored regularly, and therapeutic drug monitoring is recommended for itraconazole to ensure adequate blood levels (target trough level >1 μg/mL) 1.
- Patients with immunosuppression may require longer treatment courses, sometimes even lifelong suppressive therapy 1.
Treatment Approach
- The choice of treatment depends on the severity of the disease and the presence of central nervous system involvement 1.
- Liposomal amphotericin B is preferred for initial treatment due to its efficacy and reduced toxicity compared to amphotericin B deoxycholate 1.
- Itraconazole is the preferred oral azole for step-down therapy due to its high efficacy and relatively low toxicity 1.
- Voriconazole and posaconazole may be considered as alternative agents in certain cases, but their use is based on limited clinical experience 1.
From the FDA Drug Label
Amphotericin B for Injection USP is specifically intended to treat potentially life-threatening fungal infections: ... North American blastomycosis, ... The treatment for disseminated blastomycosis is amphotericin B (IV), as it is indicated for the treatment of North American blastomycosis, which can be disseminated 2.
- Key points:
- Amphotericin B is used for potentially life-threatening fungal infections
- It is specifically intended to treat North American blastomycosis
- Disseminated blastomycosis is a potentially life-threatening fungal infection that can be treated with amphotericin B (IV)
From the Research
Disseminated Blastomycosis Symptoms and Treatment
- Disseminated blastomycosis is a serious fungal disease that can manifest with various symptoms, including skin lesions, and can involve multiple organs such as the lungs, skin, bones, and central nervous system 3, 4, 5.
- The treatment for disseminated blastomycosis depends on the severity of the disease and the patient's immune status 3, 6, 4.
- For severe cases, involving the central nervous system, or in immunosuppressed patients, initial treatment with amphotericin B is recommended 3, 6, 4.
- For mild to moderate cases, oral itraconazole is recommended as primary therapy, and can also be used as step-down therapy after initial treatment with amphotericin B 3, 6, 4.
- Other antifungal agents such as voriconazole and posaconazole can be used in patients who do not tolerate itraconazole 3.
- Treatment should be provided to all symptomatic cases to prevent progression or recurrence of the disease 7.
Diagnosis and Clinical Presentation
- Diagnosis of disseminated blastomycosis can be made by growth of the organism in culture, histopathological identification of the yeast form in tissues, or detection of Blastomyces antigen in urine or serum 3, 4.
- Clinical presentation of disseminated blastomycosis can vary, but common symptoms include skin lesions, pulmonary symptoms, and osteoarticular involvement 4, 5.
- Disseminated blastomycosis is more common in immunosuppressed individuals, and can have a high mortality rate if left untreated 4, 7.