title: Azithromycin is not associated with QT prolongation in hospitalized patients with community-acquired pneumonia.
abstract: OBJECTIVE
  Large data-based studies have reported excess cardiovascular mortality in high-risk patients treated with azithromycin, but whether or not azithromycin causes QT prolongation remains controversial. The purpose of this study was to examine the association of azithromycin treatment on QT prolongation in a cohort of patients hospitalized with community-acquired pneumonia (CAP) METHODS: One-hundred twenty-two hospitalized patients with CAP were enrolled in the study. We compared the baseline QTc, with daily post antibiotic QTc. Other risk factors for QT prolongation such as medication or electrolyte abnormalities were recorded.
  
  
  RESULTS
  Ninety (73.8%) patients were treated with azithromycin (usually in combination with ceftriaxone), and 32 (26.2%) patients with other antibiotics (ampicillin-clavulanate, chloramphenicol, doxcycline, or ceftriaxone); 72.1% (88) of the cohort experienced QT lengthening; 72.7% with QT lengthening had a normal baseline QTc. Azithromycin was not associated with the post-antibiotic QTc. Wide (pathological) post-antibiotic QTc was associated with the pneumonia score. Every 10-point increase in the pneumonia score raised the risk for a pathological post antibiotic QTc by 1.249 (95%CI: 1.050-1.486). Analysis of patients with non-pathological baseline QTc revealed that pathological post-antibiotic QTc was only associated with previous stroke and not with the type of antibiotic.
  
  
  CONCLUSIONS
  Azithromycin treatment was not associated with QT prolongation in patients with severe CAP. Nonetheless, in a large majority of hospitalized CAP patients, QT prolongation and pathological QTc develop regardless of the antibiotic used, especially in patients with previous stroke or a higher pneumonia score.
authors.affiliation: Department of Internal Medicine C, Ha'emek Medical Center, Afula, Israel.|Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Clinical Pharmacology Unit, Ha'emek Medical Center, Haifa, Israel.
authors.forename: Lee Hilary
authors.initials: LH
authors.lastname: Goldstein
authors.affiliation: Department of Internal Medicine C, Ha'emek Medical Center, Afula, Israel.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Gabin
authors.affiliation: Department of Internal Medicine C, Ha'emek Medical Center, Afula, Israel.
authors.forename: Abdallah
authors.initials: A
authors.lastname: Fawaz
authors.affiliation: Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiology and Electrophysiology Unit, Ha'emek Medical Center, Afula, Israel.
authors.forename: Nahum Adam
authors.initials: NA
authors.lastname: Freedberg
authors.affiliation: Clinical Research Unit, Ha'emek Medical Center, Afula, Israel.|School of public health, University of Haifa, Haifa, Israel.
authors.forename: Naama
authors.initials: N
authors.lastname: Schwartz
authors.affiliation: Department of Internal Medicine C, Ha'emek Medical Center, Afula, Israel.|Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Mazen
authors.initials: M
authors.lastname: Elias
authors.affiliation: Department of Internal Medicine C, Ha'emek Medical Center, Afula, Israel.|Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Walid
authors.initials: W
authors.lastname: Saliba
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D017963:Azithromycin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced / Q000453:epidemiology*; D008297:Male; D017891:Pharmacoepidemiology; D018410:Pneumonia, Bacterial / Q000188:drug therapy* / Q000453:epidemiology; D011446:Prospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin
keywords: QT prolongation; azithromycin; hospitalization; macrolides; pharmacoepidemiology; pneumonia