title: Early use of metoprolol and serum potassium in suspected acute myocardial infarction.
abstract: In 1350 patients with suspected acute myocardial infarction, serum potassium was analysed in the emergency ward. The effect of metoprolol was compared with placebo in a double-blind randomized trial. Metoprolol increased serum potassium from 4.11 +/- 0.02 mmol/l to 4.27 +/- 0.02 mmol/l (P less than 0.001) during the 1st day after hospital admission, whereas serum potassium levels remained fairly constant in patients given placebo during the same time (4.11 +/- 0.02 to 4.14 +/- 0.02 mmol/l; P greater than 0.2). Similar results were obtained when analysing patients with a confirmed myocardial infarction separately. The effects appeared homogeneously distributed in subgroups related to sex, clinical history, infarct site, infarct size and delay time from onset of symptoms to start of treatment. We conclude that early treatment with the beta-1-selective blocker metoprolol in patients with suspected acute myocardial infarction increases serum potassium.
authors.affiliation: Department of Medicine I. Sahlgren's Hospital, University of Göteborg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Herlitz
authors.forename: A
authors.initials: A
authors.lastname: Hjalmarson
authors.forename: F
authors.initials: F
authors.lastname: Waagstein
mesh_terms: D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D011188:Potassium / Q000097:blood*; D011379:Prognosis; D014693:Ventricular Fibrillation / Q000097:blood
chemical_list: D008790:Metoprolol; D011188:Potassium