Age does not influence the serum protein binding of bupivacaine.

The serum protein binding of bupivacaine was studied in 74 subjects, 39 males and 35 females, aged 20-90 years, without evidence of acute or chronic inflammatory disease or malignancy. Subjects were drug free for at least 1 month. The free fractions of bupivacaine did not change with age in either males or females. This is in keeping with the lack of effect of age on AAG concentrations. Free fractions of bupivacaine were slightly higher in females as compared with males. The previously observed decline in clearance of bupivacaine with age probably reflects a concomitant decline in the metabolic activity of hepatic enzymes.