The pharmacokinetics of fluconazole are expected to be different in ICU patients compared to non-ICU patients and healthy volunteers due to underlying disease(s). Therefore, extrapolation of data from healthy volunteers and non-ICU patients is not possible.~To be able to include 20 patients within the study duration, a multi-centre approach is necessary.~Patients will receive standard care, as stated in the product characteristics or according to local protocols. Blood sampling for pharmacokinetic analysis will be retrieved through a central venous catheter. A maximum of 62 milliliter blood in total will be drawn for this study. Patients will be monitored daily during the treatment period for adverse events of the study drug.~Full pharmacokinetic curves will be taken on day 3 of iv therapy. Limited pharmacokinetic curves will be taken on day 7 of iv therapy. These two moments of pharmacokinetic analysis will enable the determination steady state and enable the determination of intra-individual variability.~As probably not all patients included will be treated with iv fluconazole for 7 days, switching to oral/enteral therapy is allowed after day 3. To assess bioavailability limited pharmacokinetic curves will be taken on day 3 of oral/enteral therapy.
The pharmacokinetics of fluconazole are expected to be different in ICU patients compared to non-ICU patients. The investigators will determine fluconazole and free fluconazole concentrations in 20 ICU patients, who will get intravenous fluconazole as standard care. Switching to oral/enteral fluconazol is allowed after day 3.~A full pharmacokinetic curve will be taken on day 3 of iv therapy and limited pharmacokinetic curves on day 7 of iv therapy and/or on day 3 of oral therapy; trough levels will be taken daily after intravenous therapy.