TY - JOUR A1 - Shah, Nirav R. A1 - Bulitta, Jürgen B. A1 - Kinzig, Martina A1 - Landersdorfer, Cornelia B. A1 - Jiao, Yuanyuan A1 - Sutaria, Dhruvitkumar S. A1 - Tao, Xun A1 - Höhl, Rainer A1 - Holzgrabe, Ulrike A1 - Kees, Frieder A1 - Stephan, Ulrich A1 - Sörgel, Fritz T1 - Novel population pharmacokinetic approach to explain the differences between cystic fibrosis patients and healthy volunteers via protein binding JF - Pharmaceutics N2 - The pharmacokinetics in patients with cystic fibrosis (CF) has long been thought to differ considerably from that in healthy volunteers. For highly protein bound β-lactams, profound pharmacokinetic differences were observed between comparatively morbid patients with CF and healthy volunteers. These differences could be explained by body weight and body composition for β-lactams with low protein binding. This study aimed to develop a novel population modeling approach to describe the pharmacokinetic differences between both subject groups by estimating protein binding. Eight patients with CF (lean body mass [LBM]: 39.8 ± 5.4kg) and six healthy volunteers (LBM: 53.1 ± 9.5kg) received 1027.5 mg cefotiam intravenously. Plasma concentrations and amounts in urine were simultaneously modelled. Unscaled total clearance and volume of distribution were 3% smaller in patients with CF compared to those in healthy volunteers. After allometric scaling by LBM to account for body size and composition, the remaining pharmacokinetic differences were explained by estimating the unbound fraction of cefotiam in plasma. The latter was fixed to 50% in male and estimated as 54.5% in female healthy volunteers as well as 56.3% in male and 74.4% in female patients with CF. This novel approach holds promise for characterizing the pharmacokinetics in special patient populations with altered protein binding. KW - cystic fibrosis patients KW - healthy volunteers KW - cefotiam KW - beta-lactam antibiotics KW - population pharmacokinetics KW - protein binding KW - allometric scaling KW - body size KW - body composition KW - S-ADAPT Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196934 SN - 1999-4923 VL - 11 IS - 6 ER -