title: Hemodynamic comparison of twice daily metoprolol tartrate with once daily metoprolol succinate in congestive heart failure.
abstract: OBJECTIVE
  To compare the hemodynamic effects of twice daily metoprolol tartrate (MT) and once daily metoprolol succinate (MS) in congestive heart failure patients.
  
  
  BACKGROUND
  Adverse hemodynamic effects with MT demonstrated during initiation persist with drug readministration during chronic therapy.
  
  
  METHODS
  Patients were randomly assigned to 6.25 mg MT or 25 mg MS orally and the dose was gradually increased to a target of 50 mg twice a day or 100 mg once a day, respectively. Hemodynamic measurements were obtained at baseline and after three months of therapy--both before and after drug readministration.
  
  
  RESULTS
  Long term metoprolol therapy produced significant functional, exercise and hemodynamic benefits with no difference in response between either metoprolol preparation in the 27 patients (MT [14], MS [13]). When full dose metoprolol was readministered during chronic therapy, there were parallel adverse hemodynamic effects in both drug groups. Cardiac index decreased by 0.6 liters/min/m2 (p < 0.0001) with MT and by 0.5 liters/min/m2 (p < 0.0001) with MS. Systematic vascular resistance increased by 253 dyne-sec-cm(-5) (p < 0.001) with MT and by 267 dyne-sec-cm(-5) (p < 0.0005) with MS. Stroke volume index decreased by 7.0 ml/m2 (p < 0.0005) with MT and by 6.5 ml/m2 (p < 0.0001) with MS, while SWI decreased by 6.2 g-m/m2 (p < 0.0005) with MT and by 6.0 g-m/m2 (p < 0.001) with MS.
  
  
  CONCLUSIONS
  Metoprolol tartrate and MS produce similar hemodynamic and clinical effects acutely and chronically despite the fourfold greater starting dose of MS used in this study. A more rapid initiation with readily available starting doses of MS may offer distinct advantages compared with MT in treating chronic heart failure patients with beta-adrenergic blocking agents.
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, New York, New York, USA. marrick.kukin@mssm.edu
authors.forename: M L
authors.initials: ML
authors.lastname: Kukin
authors.forename: M M
authors.initials: MM
authors.lastname: Mannino
authors.forename: R S
authors.initials: RS
authors.lastname: Freudenberger
authors.forename: J
authors.initials: J
authors.lastname: Kalman
authors.forename: C
authors.initials: C
authors.lastname: Buchholz-Varley
authors.forename: O
authors.initials: O
authors.lastname: Ocampo
mesh_terms: D000284:Administration, Oral; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D008790:Metoprolol