OBJECTIVE To establish the population pharmacokinetics(PPK)model of theophylline in elderly patients with chronic obstructive pulmonary disease,and to obtain the individual pharmacokinetic parameters for designing clinical individualized regimen.METHODS Sixty eight elderly patients in our hospital diagnosed as chronic obstructive pulmonary disease were included from April 2014 to November 2014.TDM data of theophylline and clinical materials were collected.The influences of covariate effects,including gender...