title: Influence of different bisoprolol doses on hemodynamics, plasma catecholamines, platelet aggregation, and alpha 2- and beta-receptors in hypertensive patients.
abstract: This study was designed to evaluate the effects of the beta 1-selective adrenoceptor antagonist bisoprolol on blood pressure, heart rate, plasma catecholamines, platelet aggregation, and alpha 2- and beta-adrenoceptor density in 45 male hypertensive patients (WHO stages I-II). Following a two-week placebo phase, the patients received either 5, 10, or 20 mg bisoprolol in a double-blind randomized fashion, once daily for 12 weeks. On days - 14, 0, 1, 7, 28, 56, 84, and 1 and 2 weeks after discontinuation of treatment (administration of placebo), blood pressure and heart rate were measured in the supine and sitting position, as well as during and after a 15-min exercise period on a bicycle ergometer. Simultaneously with the hemodynamic measurements, blood samples were obtained for the determination of plasma catecholamines. Blood samples for the assessment of beta-receptor density on lymphocytes and alpha 2-receptor density on thrombocytes, as well as thrombocyte aggregation sensitivity, were collected before bicycle ergometry. Five, 10, and 20 mg bisoprolol caused dose-dependent reductions of blood pressure and heart rate at rest and at peak exercise. The responder rates (diastolic BP less than or equal to 90 mm Hg) were 33%, 67%, and 100% with 5, 10, and 20 mg bisoprolol, respectively. After discontinuation of active treatment, blood pressure and heart rate gradually returned to pretreatment values within 1-2 weeks. Plasma epinephrine and norepinephrine levels in patients in the supine position remained unchanged during the whole course of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D017298:Bisoprolol; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000378:metabolism; D009994:Osmolar Concentration; D010974:Platelet Aggregation / Q000187:drug effects*; D011412:Propanolamines / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D011941:Receptors, Adrenergic / Q000378:metabolism*
chemical_list: D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D011412:Propanolamines; D011941:Receptors, Adrenergic; D017298:Bisoprolol