Population pharmacokinetics of inhaled fluticasone furoate and vilanterol in adult and adolescent patients with asthma.

OBJECTIVES

Population pharmacokinetic (PK) methods were used to characterize the PK of fluticasone furoate (FF) and vilanterol (VI) in patients with asthma following once daily inhaled FF/VI and FF and to identify significant covariates that impact the PK.

MATERIALS AND METHODS

Four of the five studies in the meta-analysis were conducted in patients with asthma (> 90%), the fifth in healthy subjects. FF data were described by a two-compartment model with first order absorption and elimination. VI data were described by a three-compartment model with zero-order absorption and first order elimination.

RESULTS

Race was a significant covariate on inhaled clearance (CL/F) of FF PK. AUC(0-24) for Asian patients was on average 33 - 53% higher than for non-Asians. Race was also a significant covariate on VI PK, with lower (81%) central volume of distribution (Vc/F) for Asian patients compared with non-Asians; VI C(max) was 220 - 287% higher in Asian patients. Treatment (combination or monotherapy), predicted percentage FEV(1), and other demographic variables did not influence the PK of FF or VI.

CONCLUSIONS

Combination of FF/VI does not appear to affect the PK of FF or VI. The effect of race on PK of FF or VI does not have impact on dosage adjustments for FF/VI in East Asian patients with asthma.