TY - JOUR T1 - Population pharmacokinetics of high dose ibuprofen in cystic fibrosis JF - Archives of Disease in Childhood JO - Arch Dis Child SP - 1128 LP - 1130 DO - 10.1136/adc.88.12.1128 VL - 88 IS - 12 AU - I Arranz AU - A Martín-Suárez AU - J M Lanao AU - F Mora AU - C Vázquez AU - A Escribano AU - M Juste AU - J Mercader AU - E Ripoll Y1 - 2003/12/01 UR - http://adc.bmj.com/content/88/12/1128.abstract N2 - Aims: To evaluate ibuprofen population pharmacokinetics in a large series of data collected in children with cystic fibrosis (CF) treated with high doses of ibuprofen (59 patients; 2–18 years), and to identify the main causes responsible for the considerable interindividual variability in ibuprofen serum levels. Methods: Blood samples were collected during routine clinical care; serum ibuprofen concentrations were determined by HPLC. Fitting of the concentration/time data to a one compartment kinetic population model was performed by a non-linear mixed effect regression method. Results: Body weight, dose, and ibuprofen dosage form (lysinate salt or the free acid form), for elimination clearance (CL/F); and body weight, dose, and fasting status for the apparent distribution volume (Vd/F) proved to be the covariates with influence in the model. The four factors identified helped to explain part of the interindividual variability observed, but the remaining unexplained variability made therapeutic drug monitoring absolutely essential. ER -