From the Guidelines
Treatment failure of oral candidiasis is often due to underlying factors such as immunosuppression, continued antibiotic use, poor oral hygiene, or uncontrolled diabetes, and switching to a different antifungal medication or increasing the dosage and duration of the current treatment may be necessary. The causes of failed treatment of oral candidiasis (thrush) can be multifaceted, including resistance to fluconazole or other azoles, which is predominantly the consequence of previous repeated and long-term exposure to these medications 1. According to the 2016 update by the Infectious Diseases Society of America, fluconazole-refractory infections should be treated initially with itraconazole solution, with a response rate of between 64% and 80% of patients 1.
Some key factors that contribute to treatment failure include:
- Immunocompromised state, particularly in patients with HIV infection and low CD4 counts (<200 cells/μL) 1
- Previous exposure to azole antifungals, leading to resistance 1
- Presence of non-albicans Candida species, such as C. glabrata, C. dubliniensis, and C. krusei 1
- Poor oral hygiene and continued use of antibiotics 1
- Uncontrolled diabetes and other underlying medical conditions 1
In cases of treatment failure, posaconazole suspension (400mg twice daily) or voriconazole (200mg twice daily) may be effective alternatives, with posaconazole suspension showing efficacy in approximately 75% of patients with refractory oropharyngeal or esophageal candidiasis 2, 1. It is essential to identify and address underlying factors contributing to treatment failure and consider laboratory confirmation through culture and sensitivity testing to guide treatment decisions 1. Consultation with an infectious disease specialist may be necessary to determine the most appropriate treatment approach for severe or persistent cases.
From the FDA Drug Label
An inadequate period of treatment may lead to recurrence of active infection. The causes of failed treatment of oral candidiasis (thrush) include inadequate treatment duration.
- Inadequate period of treatment may lead to recurrence of active infection 3.
From the Research
Causes of Failed Treatment of Oral Candidiasis
The causes of failed treatment of oral candidiasis (thrush) can be attributed to several factors, including:
- Resistance to medications, particularly in immunocompromised hosts 4
- Inadequate treatment duration, as nystatin and miconazole require a long time to eradicate the infection 5
- Drug interactions, such as those associated with miconazole 5
- Presence of underlying systemic factors, such as immunosuppression or other medical conditions 6
- Infection with Candida strains that are resistant to commonly used antifungal agents, such as fluconazole 7
Factors Contributing to Treatment Failure
Other factors that may contribute to treatment failure include:
- Virulence of the infection 7
- Type of candidiasis 7
- Inadequate diagnosis or misdiagnosis of the infection 6
- Ineffective treatment regimens or dosing schedules 6
- Lack of patient compliance with treatment instructions 5
Antifungal Resistance and Treatment Failure
Antifungal resistance is a significant concern in the treatment of oral candidiasis, with some Candida strains developing resistance to commonly used antifungal agents, such as fluconazole 4, 7. This highlights the need for alternative treatment options and the development of new antifungal agents to combat resistant strains 5, 6.