Predicted steady-state geometric mean concentration-time profiles of (A) racemic BUP (blue), OHBUP (red), THR (black), and ERY (gray) and (B) individual enantiomers R-BUP (solid blue), S-BUP (dashed blue), RR-OHBUP (solid red), SS-OHBUP (dashed red), RR-THRHBUP (solid black), SS-THRHBUP (dashed black), SR-ERYHBUP (solid gray), and RS-ERYHBUP (dashed gray) after twice-daily oral BUP (100 mg) administration for 13 days, after which terminal elimination is depicted to 30 days.