Pharmacokinetics of Micafungin in Patients of Intensive Care Units

Invasive fungal infections (IFIs) are a frequent cause of morbidity and mortality in high-risk patients, such as immunocompromised patients. Candida is currently the predominant fungal pathogen in these patient populations and is associated with significant morbidity and a high mortality. Micafungin (MCF) is a semisynthetic compound belonging to the new class of antifungal agents, the echinocandin lipopeptides, that has potent in vitro and experimental in vivo activity against a variety of pathogenic Candida species and Aspergillus species. Its applied indications are so the treatment and/or the prophylaxis of Candida and Aspergillus infections. MCF is currently licensed for the treatment of candidiasis at doses of either 100 or 150 mg a day. The efficacy of MCF is linked to the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC0-24/ MIC ratio). On one hand: \- It was demonstrated that 98% of invasive candidiasis patients with a MCF AUC/MIC ratio between 3 and 12 achieve microbiological clearance, as opposed to only 85% of those with an AUC/MIC ratio \285 achieve microbiological clearance, as opposed to 82% of those below that exposure level.(1) On the other hand: * It is well known that patients of intensive care units (ICU) are characterized by particular pharmacokinetic parameters with higher apparent volume of distribution (VC/F) and/or higher apparent systemic clearance (CL/F). In a population of healthy volunteers, it was observed that CL/F of MCF presents a high interpatient variability.(2) * Whether most ICUs patients achieve optimal AUC/MIC ratio thresholds at standard doses has not been investigated so far. In particular, lower AUCs might be reached in patients having the highest VC/F values. Such patients would then be at risk of therapy failure and would