Table 1. Estimation of the Risk of Stereoselective In Vivo Drug–Drug Interactions^a.

transporter	drug	IC50 [μM]	study design	Imax [μM]	fu,p	risk score [Imax, u/IC50]
OCT1	(R)-bupivacaine	10.2	single dose (30 mg), intravenous administration37	0.228	0.0737	0.005
	(S)-bupivacaine	18.7		0.154	0.0537	0.003
OCT2	(R)-amisulpride	9.4	single dose (50 mg), oral administration38	0.158	0.8439	0.014
	(S)-amisulpride	29.8		0.182		0.005
	(R)-bupivacaine	21.4	single dose (30 mg), intravenous administration37	0.228	0.0737	0.003
	(S)-bupivacaine	48.4		0.154	0.0537	0.001
	(R)-citalopram	17.8	multiple doses (40 mg, once daily for 21 d), oral administration40	0.228	0.2041	0.003
	(S)-citalopram	10.7		0.154		0.003
	(E)-doxepine	0.55	single dose (75 mg), oral administration42	0.286	0.2543	0.130
	(Z)-doxepine	2.26		0.039		0.004
	(R)-verapamil	8.2	multiple doses (80 mg, thrice daily for 7d), oral administration44	0.519	0.0545	0.003
	(S)-verapamil	4.6		0.216	0.0845	0.004
OCT3	(E)-doxepine	33.0	single dose (75 mg), oral administration42	0.286	0.2543	0.002
	(Z)-doxepine	14.9		0.039		<0.001
	(R)-propranolol	195	single dose (80 mg), oral administration46	0.228	0.2547	<0.001
	(S)-propranolol	69		0.154	0.2047	<0.001

^aC_max: maximum plasma concentration. f_u,p: fraction unbound in plasma. I_max: mean steady state C_max (I_max was replaced by C_max when no stereoselective steady-state pharmacokinetic data were available). I_max,u: unbound maximal plasma concentrations.