title: The use of labetalol as a moderate hypotensive agent in otological operations--plasma concentrations after intravenous administration.
abstract: The usefulness of labetalol, a combined alpha and beta adrenoceptor antagonist, as a moderate hypotensive agent during combination anaesthesia in otological operations was studied. These preliminary results show that an intravenous dose of 2.0 mg/kg of body weight of labetalol causes a moderate decrease in blood pressure without a concomitant increase in heart rate or excessive hypotension. The half-life of the elimination phase of labetalol in plasma varied between 3.9 and 6.3 hours. A direct relationship between the intravenous dose of the drug (0.5, 1.0 and 2.0 mg/kg i.v.) and the increase in the AUC value was observed. No correlation was found between the decrease in either the systolic or diastolic blood pressure and the plasma level of labetalol. This new type of antagonist may possess advantages over other current hypotensive drugs, i.e lack of tachycardia and excessive hypotension.
mesh_terms: D000328:Adult; D000758:Anesthesia; D001794:Blood Pressure / Q000187:drug effects*; D004311:Double-Blind Method; D004423:Ear / Q000601:surgery*; D004983:Ethanolamines / Q000494:pharmacology*; D005260:Female; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D007741:Labetalol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008297:Male; D013997:Time Factors
chemical_list: D004983:Ethanolamines; D007741:Labetalol