No stereoselective first-pass hepatic extraction of propranolol.
The plasma level: time profile for l-propranolol and total propranolol concentrations were examined in normotensive subjects after intravenous and oral dl-propranolol. l-Propranolol concentrations in plasma accounted for about 60% of total propranolol. This was attributed to lower volume of distribution for the isomer. Mean plasma clearance of 1-propranolol was similarly affected while apparent plasma half-life for the l-isomer and total propranolol were of the same order. Oral bioavailability of 1- and total propranolol averaged 40.7 +/- 8.5% and 42.4 +/- 12.9%. Food and hydralazine increased oral bioavailability of total and l-propranolol by similar magnitudes. We conclude that difference in the kinetics of l- and total propranolol concentrations in plasma are small and probably of no clinical significance. Presystemic clearance of propranolol in man does not appear to be stereospecific.
D000284:Administration, Oral; D001682:Biological Availability; D005260:Female; D005502:Food; D006207:Half-Life; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology; D007275:Injections, Intravenous; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D011433:Propranolol / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D011897:Random Allocation; D013237:Stereoisomerism; D013997:Time Factors
D006834:Hydrazines; C029424:hydrazine; D011433:Propranolol