* p<0.001 vs Placebo; ° p =0.002 vs Placebo
In the active-controlled clinical study conducted in Europe, silodosin 8 mg once daily was shown to be non inferior to tamsulosin 0.4 mg once daily: the adjusted mean difference (95 % CI) in the IPSS Total Score between treatments in the per-protocol population was 0.4 (0.4 to 1.1). The responder rate (i.e. improvement in the IPSS total score by at least 25 %) was significantly higher in the silodosin (68 %) and tamsulosin group (65 %), as compared to placebo (53 %).
In the long-term open-label extension phase of these controlled studies, in which patients received silodosin for up to 1 year, the symptom improvement induced by silodosin at week 12 of treatment was maintained over 1 year.
No significant reduction in supine blood pressure was observed in all clinical studies conducted with silodosin.
Silodosin 8 mg and 24 mg daily had no statistically significant effect on ECG intervals or cardiac repolarisation relative to placebo.
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with Urorec in all subsets of the paediatric population in BPH (see section 4.2 for information on paediatric use).
5.2 Pharmacokinetic properties
 The pharmacokinetics of silodosin and its main metabolites have been eva luated in adult male subjects with and without BPH after single and multiple administrations with doses ranging from 0.1 mg to 48 mg per day. The pharmacokinetics of silodosin is linear throughout this dose range.
The exposure to the main metabolite in plasma, silodosin glucuronide (KMD-3213G), at steady-state is about 3fold that of the parent drug. Silodosin and its glucuronide reach steady-state after 3 days and 5 days of treatment, respectively.
Absorption
Silodosin administered orally is well absorbed and absorption is dose proportional. The absolute bioavailability is approximately 32 %.
An in vitro study with Caco2 cells showed that silodosin is a substrate for Pglycoprotein.
Food decreases Cmax by approximately 30 %, increases tmax by approximately 1 hour and has little effect on AUC.
In healthy male subjects of the target age range (n=16, mean age 55±8 years) after once-a-day oral administration of 8 mg immediately after breakfast for 7 days, the following pharmacokinetic parameters were obtained: Cmax 87±51 ng/ml (sd), tmax 2.