Pharmacokinetics of Micafungin During Continuous Venovenous Hemofiltration

Micafungin is a cyclic lipopeptide antifungal agent of the echinocandin class. Members of this class of antifungal agents are known to inhibit the synthesis of glucan polymers in fungal cell walls. The spectrum of activity of micafungin includes Candida (all species, including strains resistant to fluconazole), Aspergillus, and Pneumocystis.

In intensive care patients continuous venovenous haemodiafiltration (CVVHDF) is a well-established extracorporal renal replacement therapy with a high clearance rate.

Pharmacokinetic studies of antifungal agents in critically ill patients treated with CVVHDF are rare. Elimination of any given drug by renal replacement therapy is determined by several major factors which are membrane specific, due to physico-chemical properties of the drug and characteristics of the renal replacement technique used.

Ten intensive-care patients with acute renal failure and suspected or proven candida infection are included into the study.

100 mg Micafungin will be infused over a period of sixty minutes via a central venous catheter, different from the venous catheter used for CVVHDF. Blood samples will be drawn on days 1 and 2 from the arterial and venous line of the extracorporeal circuit at 0, 2, 4, 6, 8 and 24h after starting the infusion. Plasma and ultrafiltration samples, collected from the outlet of the ultrafiltrate compartment of the hemofilter, will be taken at corresponding times.

The following pharmacokinetic parameters will be determined: area under the curve (AUC), half-live (t1/2), maximum plasma concentration (Cmax) and elimination fraction.