Carvedilol inhibits reactive oxygen species generation by leukocytes and oxidative damage to amino acids.

The purpose of this study was to test whether carvedilol has an antioxidant effect in humans in vivo. We administered 3.125 mg of carvedilol twice daily to normal subjects for 1 week. ROS generation by polymorphonuclear leukocytes and mononuclear cells fell from 314+/-183.43 and 303+/-116 mV to 185+/-157 and 189+/-63 mV (P<0.025), respectively. m-Tyrosine fell from 4.24+/-0.99 to 4.03+/-0.97 ng/mL (P=0.01), and o-tyrosine fell from 4.59+/-1.10 to 4.24+/-0.99 ng/mL (P=0.004) in the absence of a change in phenylalanine concentrations. We conclude that carvedilol significantly inhibits ROS generation by leukocytes and oxidative conversion of phenylalanine to m- and o-tyrosine.