Bicalutamide Pharmacokinetics and Metabolism

once daily as monotherapy for the treatment of early (localised or locally advanced) nonmetastatic prostate cancer. It is used at a dosage of 50mg once daily in combination with a luteinising hormone-releasing hormone analogue or surgical castration for the treatment of advanced prostate cancer. Bicalutamide is a racemate and its antiandrogenic activity resides almost exclusively in the (R)-enantiomer, with little, if any, activity in the (S)-enantiomer. (R)-Bicalutamide is slowly and saturably absorbed, but absorption is unaffected by food. It has a long plasma elimination half-life (1 week) and accumulates about 10-fold in plasma during daily administration. (S)Bicalutamide is much more rapidly absorbed and cleared from plasma; steadystate concentrations (Css) of (R)-bicalutamide are 100-fold higher than those of (S)-bicalutamide. Css increases linearly with doses up to 50mg, but nonlinearly at higher doses, reaching a plateau above 300mg. Css is higher in Japanese than in