title: Plasma concentrations and bioavailability of propranolol by oral, rectal, and intravenous administration in man.
abstract: Eight normal male volunteers received 80 mg doses of propranolol by the oral and rectal routes and 2.2 mg by intravenous administration in a crossover fashion. Plasma concentrations of propranolol were measured by a gas chromatographic method using an electron capture detector. Individual subject concentration-time data were analysed and results indicated that the data fit a two compartment model with first order absorption. An approximately two-fold higher plasma propranolol concentration was observed after rectal administration as compared with oral dosing. Statistical analysis of the difference in the total AUCs indicates a significantly higher bioavailability of propranolol administered by the rectal route. The reduced bioavailability after oral administration indicates a substantial first pass effect but that it is possible to bypass the liver, at least partially, by giving the drug rectally to man.
mesh_terms: D000284:Administration, Oral; D000285:Administration, Rectal; D000328:Adult; D001682:Biological Availability; D006801:Humans; D007262:Infusions, Intravenous; D007700:Kinetics; D008297:Male; D011433:Propranolol / Q000008:administration & dosage / Q000097:blood*
chemical_list: D011433:Propranolol