Table 1.

Effective doses of cGMP-PDE inhibitors

Target	Drug	IC50	EC50a	Human Plasma [Cmax]
PDE5	Sildenafil	3.9 nM(Gupta et al., 2005)	66-271 µM (Li et al., 2013; Mei et al., 2015)	1.2 µM(Gupta et al., 2005) (100 mg dose)
	Tadalafil	1-5 nM(Gupta et al., 2005; Ahmed, 2018)	38 µM(Li et al., 2013)	0.87 µM(Gupta et al., 2005) (20 mg dose)
	Exisulind	113 µM(Soh et al., 2000)	165-557 µM(Thompson et al., 2000)	13-27 µM(van Stolk et al., 2000) (40-200 mg dose)
PDE9	Pf-04447943	12 nM(Charnigo et al., 2019)	90 µMb	0.12-0.63 µM (Charnigo et al., 2019)
	BI-409306	52 nM(Rosenbrock et al., 2019)	ND	1.37 µM(Moschetti et al., 2016) (100 mg dose)
PDE10	TAK-063	0.3 nM(Harada et al., 2015)	22 µMb	0.57 µM(Tsai et al., 2016) (1000 mg dose)
	Pf-2545920	0.16 nM(Lee et al., 2016)	14-20 µM(Lee et al., 2016)	0.1-0.52 µM(Delnomdedieu et al., 2017) (10-30 mg dose)

^aInhibition of colon cancer cell growth.

^bFrom the present study. ND: Not determined.