Single and repeat dose median plasma semi-log concentration–time profiles for fluticasone furoate (FF; 0–48 h) and vilanterol trifenatate (VI; 0–12 h) after co-administration of ketoconazole or placebo and FF/VI (study 2). , single dose FF/VI + placebo; , single dose FF/VI + ketoconazole; , repeat dose FF/VI + placebo; , repeat dose FF/VI + ketoconazole; and , lower limit of quantification (LLQ) 10 pg ml–1