Table 4.
Uroselectivity: Inhibition of Phenylephrine-Mediated Responses in Anesthetized Rats (n = 5–8)
| Urethral Pressure (ID50) (μγ/kg) | Blood Pressure (ED15) (μγ/kg) | Uroselectivity (BP/UP) | |
| Intravenous Injection | |||
| Silodosin | 1.4 | 12 | 8.6 |
| Tamsulosin | .67 | .70 | 1.0 |
| Prazosin | 4.8 | 1.4 | .3 |
| Terazosin | 49 | 7.3 | .15 |
| Intraduodenal Injection | |||
| Silodosin | 54 | 870 | 16.1 |
| Tamsulosin | 19 | 61 | 3.2 |
| Prazosin | 48 | 24 | .5 |
| Terazosin | – | – | – |
BP, blood pressure; ED15, dose required to reduce BP by 15%; ID50, dose required to inhibit the increase in intraurethral pressure by 50%; UP, urethral pressure.
Data from Akiyama K et al.31