Pharmacokinetics and safety of oral posaconazole in neutropenic stem cell transplant recipients

The pharmacokinetics of posaconazole oral suspension in neutropenic patients undergoing high-dose chemotherapy and stem cell transplantation were evaluated, and the association of plasma posaconazole exposure with the presence and severity of oral mucositis was explored in this nonrandomized, open-label, parallel-group, multiple-dose pharmacokinetic study. Thirty patients were enrolled and received one of three regimens (group I, 200 mg once daily; group II, 400 mg once daily; group III, 200 mg four times daily) for the duration of neutropenia. The mean total exposure for day 1, as shown by the area under the concentration-time curve from 0 to 24 h (AUC_0-24), was 1.96 mg · h/liter in group I and was 51% higher in group II and in group III. Increases in AUC_0-24 and maximum plasma concentration (C _max) in groups II and III were dose related. The AUC_0-24 and C_max values on day 1 were similar between groups II and III. There was interpatient variability of up to 68% in the pharmacokinetic values for our study population. Steady state was attained by days 5 to 6. Average steady-state plasma posaconazole trough values were 192, 219, and 414 ng/ml in groups I, II, and III, respectively. The AUC_0-24 and apparent oral clearance increased by increasing dose and dosing frequency. Mucositis appeared to reduce exposure but did not significantly affect mean total posaconazole exposure (AUC and C_max) at steady state (P = 0.1483). Moreover, this reduction could be overcome by increasing the total dose and dosing frequency. Posaconazole was safe and well tolerated.