Relative to placebo , yohimbine significantly increased hydromorphone demand inelasticity , more so for hydromorphone 1-mg units ( P ( max ) = 909 , 3,647 , and 3,225 for placebo , 16.2 , and 32.4 mg yohimbine doses , respectively ) than hydromorphone 2-mg units ( P ( max ) = 2,656 , 3,193 , and 3,615 , respectively ) .
