Antifungal prophylaxis with posaconazole tablet and oral suspension in patients with haematologic malignancy: Therapeutic drug monitoring, efficacy and risk factors for the suboptimal level

Background: Posaconazole is used to prevent invasive fungal infections (IFIs) in patients with haematologic malignancy. In this study, we compared plasma posaconazole concentrations (PPCs) and the incidence of breakthrough IFIs between patients with haematologic malignancy receiving posaconazole oral suspension vs tablet. Methods: We retrospectively collected data on adult patients with haematologic malignancies who received posaconazole prophylaxis during chemotherapy from April 2014 through May 2018. A total of 242 cases with PPCs, 88 in the oral suspension group and 154 in the tablet group, were included in this study. Results: Patients receiving tablets achieved a significantly higher mean PPC than did those on oral suspension (1.631 ± 0.878 μg/mL in the tablet group vs. 0.879 ± 0.585 μg/mL in the oral suspension group). One hundred and thirty-seven of 154 patients (89.0%) receiving tablets had PPCs of 0.7 μg/mL or more, while only 41 of 88 patients (46.6%) receiving oral suspension attained an optimal level (P <.001). The incidence of breakthrough IFIs was significantly higher in the oral suspension group compared with in the tablet group (14.8% of oral suspension vs. 4.5% of tablet; P =.005). In the analysis including patients receiving posaconazole tablets, hypoalbuminemia (< 3.5 g/dL) was found to be a risk factor associated with suboptimal levels (odds ratio: 8.872; 95% confidence interval: 3.011 - 26.141; P <.001). Conclusions: Suboptimal PPCs in the tablet group were less common than those in the oral suspension group. Therapeutic drug monitoring may be still necessary even in patients receiving posaconazole tablets, especially in those with hypoalbuminemia.