Flucytosine and its clinical usage

Flucytosine is an antifungal agent first licensed in the 1970's. However, its clinical value has long been overlooked and its availability across the globe is limited. This review highlights the important clinical and pharmacological aspects of flucytosine. This a narrative review of the clinical and in vitro susceptibility literature, with a focus on clinical uses for flucytosine. Detailed literature review including early literature related to primary and acquired resistance to flucytosine. Flucytosine has good antifungal activity against Cryptococcus species, Candida species, and dematiaceous fungi. Its water solubility enables good penetration into the eye, urinary tract, central nervous system (CNS), cardiac vegetations and fungal biofilms. In combination with amphotericin B, it shows early fungicidal activity against Cryptococcus species, and this translates to ~20% improved survival in cryptococcal meningitis. Combination therapy also reduces the mortality of Candida meningitis, and should be used in neonatal candidiasis because of the high frequency of CNS infection. Monotherapy for urinary candidiasis is under-studied, but is usually effective. It is probably valuable in the treatment of Candida endocarditis and endophthalmitis: there are few data. It is not effective for aspergillosis or mucormycosis. Flucytosine monotherapy of urinary candidiasis resulted in 22% developing resistance on therapy and failing therapy, and in 29% of 21 patients with cryptococcosis. Certain regions of the world still do not have access to flucytosine compromising the management of certain severe fungal infections. Flucytosine has an important role in combination therapy for yeast and dematiaceous infections and probably as monotherapy for urinary candidiasis, with a modest risk of resistance emergence. Facilitating access to flucytosine in those regions (especially low-income countries) might alleviate the mortality of invasive fungal diseases.

A Case of Candidemia after Long-term Presence of Urethral Foreign Bodies

A 52-year-old man presented to our hospital complaining of general malaise, cough, and fever. Total body computed tomography revealed scattered pneumonia and urethral foreign bodies that had been inserted during adolescence. Candida glabrata was detected in blood and urine cultures. Based on these findings, the patient was diagnosed with candidemia that developed due to Candida urinary tract infection, complicated by septic pulmonary embolism and severe diabetes mellitus. Candidemia likely persisted despite the initiation of intravenous antifungal therapy and control of blood sugar level. Therefore, surgical removal of the urethral foreign bodies was performed, which resulted in resolution of the patient’s symptoms. Herein, we report a rare case of candidemia complicated by Candida urinary tract infection that developed due to the long-term presence of urethral foreign bodies. A multidisciplinary therapeutic approach, including surgical removal of the infected foreign bodies, is effective in such cases. This case indicates that long-term presence of foreign bodies and acquired immune dysfunction can be risk factors for candidemia. Therefore, detailed history should be obtained and systemic examination should be performed to identify the complicating risk factors on diagnosis of candidemia.

Candida urinary tract infections in adults

Candiduria is commonly seen in hospitalized patients and most of the patients are asymptomatic, but it may be due to cystitis, pyelonephritis, prostatitis, epididymo-orchitis or disseminated candidiasis. Major risk factors are diabetes mellitus, indwelling urinary catheters, use of broad-spectrum antibiotics, urinary obstruction, and admission to intensive care units. Candida urinary tract infections can be caused by hematogenous spread following candidemia, or retrograde route via the urethra. The presence of Candida species in urine in asymptomatic patients does not warrant antifungal therapy except neutropenic patients, very low-birth-weight infants and patients undergoing urologic procedures. Fluconazole is the treatment of choice for symptomatic infections, it achieves high urinary levels. The other azole antifungals and echinocandins do not reach sufficient urine levels. Amphotericin B deoxycholate is the alternative antifungal agent if fluconazole can not be used because of resistance, allergy or failure.

Successful treatment with caspofungin of candiduria in a child with Wilms tumor; review of literature

Symptomatic candiduria often occurs in patients with indwelling bladder catheters or immunocompromised host. Isolation of Candida in urine in high-risk patients should primarily be considered as a marker for candidemia. Hematological and genitourinary malignancies are one of the main risk factors associated with Candida urinary tract infections (CUTI). Fluconazole is a choice for initial treatment of CUTI, but it is fluctuate depending on the patient's condition including renal failure, site of urinary infection and Candida species. Poor glomerular filtration is the main disadvantage echinocandins resulting in very low urinary concentrations. Therefore, echinocandins have prohibited their use in CUTI. Up to now, there are only 10 cases reported in the literatures with highly effective echinocandins in CUTI because of high concentrations in the tissue are needed to control invasive fungal disease. Herein, we report a candiduria followed by renal candidiasis caused by Candida albicans in a 6-year-old Iranian male with a history of Wilms tumor in left kidney. Direct examination of urine specimen revealed an infection due to budding yeast cells with numerous pseudohyphae and growths of C. albicans was reconfirmed by sequencing of ITS rDNA region. MICs in increasing order were as follows: caspofungin (0.016μg/ml), voriconazole (0.125μg/ml), amphotericin B (0.25μg/ml), itraconazole (0.5μg/ml) and fluconazole (2μg/ml). It seems that successful treatment with caspofungin owes achieved high renal tissue concentrations that are unrelated to glomerular filtration. In conclusion, predisposing factors for better outcome are more important than treatment of CUTI, therefore, management of UTI is essential for critically patients.