Assessment and Treatment of Fungal Lung Infections

Invasive fungal infections

Invasive fungal infections occur in both immunocompetent and immunocompromised patients.

Endemic Fungal Infections

Endemic fungal infections can affect both healthy and immunocompromised patients.

Species	Remark(s)
Histoplasmosis	§ Endemic to Southeast Asian rivers § Itraconazole is used as monotherapy for mild and chronic pulmonary disease. § Amphotericin B (AmB) with itraconazole is recommended for moderate-to-severe histoplasmosis.
Blastomycosis	§ Extrapulmonary dissemination involving the skin occurs in up to 40% of cases. § Treatment includes itraconazole for mild-to-moderate disease and liposomal AmB (L-AmB) followed by itraconazole for life-threatening pulmonary infections.
Sporotrichosis	§ Sporothrix schenckii is globally located and not isolated to certain regions. § Infection results primarily from cutaneous contact with sporotrichosis. § Mild-to-moderate pulmonary disease requires itraconazole, whereas AmB followed by itraconazole is recommended for severe disease.
Coccidioido-mycosis	§ Presentation as community-acquired pneumonia in endemic areas. § Immunocompetent infected hosts may not require treatment.  § Immunocompromised patients are treated with fluconazole or itraconazole. § In serious pulmonary disease, treatment with AmB is initiated, followed by an azole.

Opportunistic Fungal Infections

Opportunistic fungal infections primarily cause infections in patients who tend to be immunocompromised. 

 

Species	Remark(s)
Aspergillosis	§ Primary treatment for invasive pulmonary aspergillosis (IPA) is voriconazole. § Alternatives include lipid-based AmB formulations, echinocandins, and posaconazole. § Data to support combination therapy are currently lacking; therefore, combination therapy is not recommended.
Cryptococcosis	§ Immunocompetent patients are typically asymptomatic, which results in a dormant infection. § Because cryptococcosis is associated with a high risk of mortality secondary to dissemination, immediate identification and treatment are necessary to avoid dissemination to the central nervous system. § For those exhibiting mild-to-moderate symptoms, fluconazole therapy is recommended. § An AmB formulation with or without flucytosine, followed by oral fluconazole, is the primary recommendation for severe symptomatic pulmonary cryptococcosis.
Candidiasis	§ Pulmonary pneumonia infection due to Candida species is rare and diagnosis can be difficult. § Colonization of the lung parenchyma with Candida species is common, yet usually will be dormant in immunocompetent person. § Many critically ill patients are empirically treated with broad-spectrum antibiotics. Further clinical deterioration and lack of improvement in these cases suggest the initiation of empiric antifungal therapy.  § Because triazole antifungals and echinocandins exhibit excellent lung penetration, they—in addition to AmB formulations—are effective for treating pulmonary candidiasis, despite the lack of specific studies regarding the treatment of Candida pneumonia.
Mucormycosis	§ Uncommon. § Occurs in patients with diabetes mellitus, organ or hematopoietic stem cell transplant, neutropenia, or malignancy. § Pulmonary mucormycosis is primarily observed in patients with a predisposing condition of neutropenia or corticosteroid use. § Treatment should include control of the predisposing problem, débridement of necrotic tissue, and antifungal therapy.  § Current recommendations for efficacious treatment of mucormycosis include AmB formulations, posaconazole, and iron chelation therapy.  § Because of the lack of literature regarding combination therapy, its use in mucormycosis is not recommended.
Pneumocystis jirovecii  Pneumonia  (PCP)	§ Originally considered a parasite, PCP is currently categorized as a fungus based on molecular similarities to fungal RNA. § Infection occurs through the inhalation of airborne spores, with further maturation occurring in the lungs. § PCP is extremely resistant to common antifungal therapy, including AmB formulations and triazole antifungals.  § Trimethoprim/sulfamethoxazole remains the mainstay for PCP treatment and prophylaxis. § If clinical improvement is not noted, failure of the first-line treatment should be considered and a second-line agent should be initiated.  § Second-line agents indicated for the treatment of PCP include primaquine plus clindamycin, atovaquone, or IV pentamidine.

Reference:

 Cook S. & Confer J. Assessment and Treatment of Fungal Lung Infections. US Pharm. 2011;36(7):HS-17-HS-24.

Accessed via: 

https://www.uspharmacist.com/article/assessment-and-treatment-of-fungal-lung-infections

[Accessed on 21 Dec 2018]