Efficacy of caspofungin in the treatment of esophageal candidiasis resistant to fluconazole

Caspofungin is a new echinocandin drug with comparable in vitro activity against azole-susceptible and -resistant isolates of Candida that could provide a less toxic alternative to amphotericin B for the management of esophageal candidiasis with clinical or laboratory evidence of decreased susceptibility to fluconazole. The authors retrospectively analyzed its efficacy in adults with endoscopically documented Candida esophagitis from four Phase II and III studies using two definitions of resistance to fluconazole: 1) clinically refractory infection based on failure of esophageal symptoms to improve despite at least 1 week of greater than or equal to200 mg/d of fluconazole; or 2) microbiologically resistant infection with either "susceptible dose-dependent" or "resistant" Candida isolates based on MICs of 16 to 32 and greater than or equal to64 mug fluconazole/mL, respectively. A favorable response required resolution of all symptoms and substantial improvement in endoscopic findings. Seven of 11 patients (64%) who had been clinically refractory to fluconazole had favorable responses to caspofungin. Eleven of 14 patients (79%) whose Candida isolates had decreased susceptibility to fluconazole had favorable responses to caspofungin, including 5 (83%) of 6 patients infected by isolates with MICs of greater than or equal to64 mug fluconazole/mL. Caspofungin appeared to be efficacious therapy for some patients with esophageal candidiasis who were clinically refractory to fluconazole or infected by Candida with reduced susceptibility to fluconazole in vitro.