Table 2.

Pharmacokinetic parameters of sildenafil citrate reported in different ethnic groups after a single oral administration of a 100-mg or 50-mg tablet.

Ethnic Group	n	Age (years)	Dose (mg)	$C_{max}$ (ng/ml)	$T_{max}$ (h)	$\mathit{AU}{C}_{0-t}$ (ng.h/ml)	$\mathit{AU}{C}_{0-\infty }$ (ng.h/ml)	$t_{\frac{1}{2}}$ (h)	$V_{\mathit{ss}}/F$	CL/F	MRT (h)	Ref.
Mexican	29	30.2	100 mg (1 tab)	765.9	0.85	1873.3 (t = 24 h)	1894.6	4.12	352.56	60.3	3.68	(Marcelín-Jiménez et al., 2012)
Mexican	30	24.4	100 mg (1 tab)	657.64	1.42	1884.97 (t = 16 h)	1983.03	3.06	—	—	3.86*	(Valenzuela et al., 2011)
Mexican	24	—	100 mg (1 tab)	1044	1.2	2960 (t = 12 h)	—	4.3	—	—	6.2	(Flores-Murrieta et al., 2000)
Iranian	11	—	100 mg (2x50 mg tabs)	840.0	1.13	2790.0 (t = 24 h)	2870.0	2.90	—	—	3.13*	(Mahmoudian et al., 2010)
Thai	15	28.8	100 mg (1 tab)	661.54	0.99	1876.36 (t = 12 h)	—	3.11	—	58.94	4.48	(Kanjanawart et al., 2011)
Caucasian	34	≈ 31.5	100 mg (1 tab)	514.0	0.95	1651.0 (t = 24 h)	1670	3.98	—	—	5.88*	(Nichols et al., 2002)
Caucasian	27	28.8	100 mg (1 tab)	302.0	3.10	1468 (t = 24 h)	—	3.48	—	—	5.03*	(Muirhead et al., 2000)
Caucasian	24	29	50 (1 tab)	254.89	0.75	— (t = 24 h)	619.88	3.79	—	—	5.47*	(Jetter et al., 2002)
Egyptian	12	22	50 (1 tab)	236.0	1.74	— (t = 12 h)	1336	2.39	134.9	40.1	2.97*	(Hedaya et al., 2005)
Egyptian	10	≈ 29	50 (1 tab)	318.35	1.25	— (t = 12 h)	484.2	1.92	—	—	2.63*	(Hegazy 2014)
Jordanian	6	30	50 (1 tab)	212.4	1.25	515.4 (t = 24 h)	564.5	1.73	—	—	2.50*	(Al-Ghazawi et al., 2010)

C_max maximum plasma concentration; T_max time to maximum plasma concentration; AUC_0-t area under the plasma concentration–time curve up to the last measurable concentration; AUC_0-∞ area under the plasma concentration–time curve up to time infinity; t_1/2 the half-life; V_ss/F apparent volume of distribution at steady state; CL/F apparent clearance; MRT mean residence time.

^*Estimated from references as (MRT = half-life/0.693).