At a baseline maximum urinary flow rate of greater than @ ml per second in @ patients the median flow rate change was -@ and -@ ml per second ( p = @ ) , at a maximum of @ to @ ml per second in @ the change was @ and @ ml per second ( p = @ ) , and at a maximum of less than @ ml per second in @ the change was @ and @ ml per second ( p = @ ) for placebo and tadalafil , respectively .