title: Comparison of Weight-Based Dose vs. Standard Dose Diltiazem in Patients with Atrial Fibrillation Presenting to the Emergency Department.
abstract: BACKGROUND
  Despite evidence-based recommended weight-based (WB) dosing of diltiazem for the initial treatment of atrial fibrillation (AF) with rapid ventricular response (RVR), many providers utilize lower initial doses of diltiazem.
  
  
  OBJECTIVE
  We sought to determine whether a low, standard dose of diltiazem is noninferior to WB diltiazem as an initial bolus dose in the treatment of AF with RVR.
  
  
  METHODS
  This retrospective review included patients who presented to the emergency department (ED) of an urban, academic tertiary medical center experiencing AF with RVR from November 2010 to August 2014. Adult patients were categorized by the dose of diltiazem received; 10 mg standard dose or 0.2-0.3 mg/kg WB dose. The primary outcome of successful treatment was defined as a composite of the following parameters 15 min after the initial bolus dose: heart rate (HR) < 100 beats/min, reduction of HR ≥ 20%, or a conversion to normal sinus rhythm.
  
  
  RESULTS
  Four hundred and fifty-six patients who received diltiazem were included for study evaluation (standard dose: n = 255 patients, WB: n = 201 patients). Baseline characteristics, medical history, and medication use before ED presentation were similar between the groups. Significant differences at baseline between the groups included weight and HR at presentation. The primary outcome of successful treatment was attained in 60.8% of the standard dose patients and 68.7% of the WB patients (p = 0.082).
  
  
  CONCLUSIONS
  In patients presenting to the ED, we found that standard dose diltiazem was noninferior to WB dosing in the initial treatment of AF with RVR.
authors.affiliation: Department of Pharmacy Services, Hartford, Connecticut.
authors.forename: Adam L
authors.initials: AL
authors.lastname: Ross
authors.affiliation: Department of Research Administration, Hartford Hospital, Hartford, Connecticut.
authors.forename: David M
authors.initials: DM
authors.lastname: O'Sullivan
authors.affiliation: Department of Emergency Medicine, Hartford Hospital, University of Connecticut School of Medicine, Hartford, Connecticut.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Drescher
authors.affiliation: Department of Pharmacy Services, Hartford, Connecticut.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Krawczynski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001835:Body Weight; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D004110:Diltiazem / Q000008:administration & dosage*; D004636:Emergency Service, Hospital; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D002121:Calcium Channel Blockers; D004110:Diltiazem
keywords: afib; atrial fibrillation; cardizem; clinical pharmacy; diltiazem; heart rate; pharmacology; rapid ventricular response