TABLE 1

Noncompartmental pharmacokinetics of racemic metoprolol in 20 healthy, young women (16 extensive and four poor metabolizers) after the administration of 100 mg of metoprolol tartrate in the absence or presence of diphenhydramine dosed to steady state

Results presented as mean ± standard deviation.

Parameter	EM (n = 16)			PM (n = 4)
Parameter		MET-PCB	MET-DPH	MET-PCB	MET-DPH
C_max (μmol/l)	0.89 ± 0.42	1.18 ± 0.34^a	1.74 ± 0.31^b	1.50 ± 0.38^b
T_max (h)	1.69 ± 0.63	1.97 ± 0.70	1.75 ± 0.20	2.06 ± 0.72
t_1/2 (h)	2.88 ± 0.80	3.95 ± 0.81^a	7.44 ± 0.8^b	7.08 ± 0.80^b
AUC_0—∞ (μmol · h/l)	4.05 ± 2.15	7.76 ± 3.34^a	17.18 ± 2.48^b	14.08 ± 3^b
CL/F (l/h)	111 ± 90	47 ± 26^a	17 ± 2.5^b	21 ± 4^b
CL_R (l/h)	3.98 ± 2.14	3.81 ± 1.39	3.64 ± 0.48	4.71 ± 1.99
CL_NR (l/h)	107.23 ± 89.12	42.99 ± 24.95^a	13.61 ± 2.29^b	16.71 ± 4.10^b
CL_{MET→α-OH-MET} (l/h)	11.97 ± 12.70	3.91 ± 3.21^a	0.04 ± 0.01^b	0.04 ± 0.01^b

↵ a P < 0.05 EMs placebo versus EMs diphenhydramine.
↵ b P < 0.05 significantly different between EMs and PMs in placebo as well as diphenhydramine week.