Limitations of caspofungin in the treatment of obstructive pyonephrosis due to Candida glabrata infection

BACKGROUND Caspofungin is a new antifungal agent with high-level activity against a number of Candida species including those that are resistant to azoles. Its good safety profile and low nephrotoxicity makes it an attractive drug to treat fungal infections in patients with compromised renal function. However, little is known about the clinical efficacy in the treatment of complicated urinary tract infections due to Candida species such as pyonephrosis. CASE PRESENTATION We report a case of obstructive pyonephrosis due to an azole (fluconazole and itraconazole) resistant Candida glabrata strain that failed to respond to intravenous treatment with caspofungin. A sustained clinical and microbiological response was only achieved after percutaneous drainage and instillation of amphotericin B deoxycholate into the renal pelvis in combination with intravenous liposomal amphotericin B. CONCLUSION This case demonstrates the limitation of intravenous antifungal agents such as caspofungin as the sole treatment of an obstructive upper urinary tract infection due to Candida species. In order to achieve long term sustained cure from an obstructive pyonephrosis, pus and fungal balls should be drained and an anti-fungal agent such as amphotericin B deoxycholate instilled locally. The pharmacokinetics and role of caspofungin in the treatment of complicated Candida urinary tract infection is reviewed.