naloxone administration resulted in significantly greater peak levels of plasma norepinephrine ( peak levels of 1.5 +/- 0.4 versus 0.9 +/- 0.1 ng/ml ) and epinephrine ( peak levels of 1.4 +/- 0.7 versus 0.9 +/- 0.3 ng/ml ) and higher norepinephrine values throughout the study period .
C0014563
epinephrine
C0028351
norepinephrine