Micafungin and caspofungin pharmacodynamics in patients with candidemia

Candidemia is an important cause of health care-associated bloodstream infections. Appropriate antifungal therapy is crucial to reduce morbidity and mortality. A previous randomized clinical trial compared the clinical effectiveness of caspofungin 50 mg, micafungin 100 mg (M100), and micafungin 150 mg (M150) in treating invasive candidiasis and candidemia. M100 treatment success was non-inferior to caspofungin, while M150 yielded less favourable clinical and mycological responses. Pharmacodynamic (PD) variables were explored to assess the effect of caspofungin, M100 and M150 on the following outcomes: mycological eradication, clinical success, days to eradication, recurrence, and emergent infection for cases of candidemia only from the aforementioned clinical trial. Univariate and multivariate analyses were performed to evaluate the ratio of area under the concentration curve to minimum inhibitory concentration [AUC:MIC] for the treatment arms. AUC:MIC >1500 conferred better mycological eradication, but an inverse relationship between micafungin and mycological eradication based on an AUC:MIC ≥7500 was found. M150 required more days to eradication than M100 (p<0.03) and caspofungin (p<0.02). A correlation was also noted for days to eradication with several other risk factors, including race, Candida parapsilosis, and neutropenia. Key words: Micafungin and caspofungin, echinocandins,