title: Effect of blood pressure angiotensin II and aldosterone concentrations during treatment of severe hypertension with intravenous labetalol: comparison with propranolol.
abstract: 1 The actions of labetalol 1.0-2.0 mg/kg intravenously on blood pressure, heart rate, plasma angiotensin II and aldosterone concentrations have been studied in 20 recumbent hypertensive patients. 2 In all subjects there was a reduction in systolic and diastolic blood pressures within 5 min of completion of injection. 3 Severe hypotension was not seen but three patients who had a marked fall in blood pressure experienced side-effects. Postural hypotension was common at the end of the study. 4 Labetalol caused significant reduction in heart rate. 5 Labetalol induced significant lowering of plasma angiotensin II and in plasma aldosterone concentrations, which were most obvious when these were increased initially; overall there was a close correlation between concurrent measurements of angiotensin II and aldosterone concentrations. 6 In five patients a comparison was made against propranolol 10 mg intravenously. Labetalol was more effective in lowering blood pressure but less effective in reducing pulse rate of plasma angiotensin II concentration.
mesh_terms: D000450:Aldosterone / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D001794:Blood Pressure / Q000187:drug effects*; D002986:Clinical Trials as Topic; D004983:Ethanolamines / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D007275:Injections, Intravenous; D007741:Labetalol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D004983:Ethanolamines; D000804:Angiotensin II; D000450:Aldosterone; D011433:Propranolol; D007741:Labetalol