title: Pharmacokinetics and pharmacodynamic studies of labetalol in hypertensive subjects.
abstract: 1 The pharmacokinetics of labetalol were studied in twelve hypertensive patients, ten of whom were not receiving other therapy. 2 Following intravenous administration there was a three- to fourfold variation in terminal elimination half-life, volume of distribution and total plasma clearance. The mean elimination half-life was 3.25 hours. 3 Following oral administration the drug was absorbed rapidly. Systemic availability varied from 11-86% (mean 33%). 4 Plasma levels correlated poorly with the acute effect on BP, raising the possibility of labetalol acting in a deep tissue compartment or alternatively an active metabolite contributing to its effect.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D004983:Ethanolamines / Q000097:blood*; D005260:Female; D006207:Half-Life; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007275:Injections, Intravenous; D007700:Kinetics; D007741:Labetalol / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D004983:Ethanolamines; D007741:Labetalol