Population pharmacokinetic methods that utilize all data including those below the lower limit of quantification were developed to describe fluticasone furoate (FF) and vilanterol (VI) systemic exposure in chronic obstructive pulmonary disease (COPD) patients following once-daily FF/VI, FF, or VI and to identify significant covariates that impact the pharmacokinetics.

Race was a significant covariate on inhaled clearance (CL/F) of FF resulting in a maximum of 30 % higher in steady-state AUC0–24 for subjects with Asian heritage compared with White/Caucasians. Age, bodyweight, sex and smoking status were significant covariates to affect the pharmacokinetics of VI.

The magnitudes of these covariate effects on systemic exposure are not large enough to warrant FF/VI dosage adjustment in patients with COPD.