Table I.

Stereospecific pharmacokinetic variables in healthy subjects (N=10) for oral metoprolol IR and ER given with and without paroxetine.

Variable	Metoprolol Enantiomer	Metoprolol IR 50mg			Metoprolol ER 100mg
		Without paroxetine	With paroxetine		Without paroxetine	With paroxetine
AUC0–24h	S	138±98	511±116	**	173±96	599±174	**
(ng*h/mL)	R	84±75	436±141	**	120±71a	521±183	**
Cl/F (L/h)	S	194±171	47±15	*	138±90b	56±46c
	R	392±913	56±27	*	292±291d	66±36c
λz(h−1)	S	0.23±0.05	0.13±0.02	**	0.04±0.03b	0.04±0.03c
	R	0.29±0.19	0.14±0.03	*	0.05±0.03d	0.05±0.02c
Tmax (h)	S	1.0±0.4	1.0±0.6		8±3	10±3
	R	1.0±0.3	1.1±0.6		5±4a	9±3	*
Cmax	S	30±23	81±17	**	10±5	35±9	*
(ng/mL)	R	20±20	73±18	**	8±4a	30±9	*
S/R AUC	S/R	1.64±0.25	1.17±0.17	**	1.65±0.37a	1.15±0.11	**
Ratio

Values are reported as geometric mean ± standard deviation.

^*P<0.05;

^**P<0.001;

^aN=9 evaluable;

^bN=6 evaluable;

^cN=5 evaluable;

^dN=7 evaluable