title: The effect of varenicline on Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio in healthy smokers and nonsmokers.
abstract: BACKGROUND
  Varenicline could affect the T wave and QT interval. The interval from the peak to the end of the electrocardiographic (ECG) T wave (Tp-e) may correspond to the transmural dispersion of repolarization, and increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. In this study, we assessed the effects of varenicline on Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio.
  
  
  METHODS
  Thirty healthy volunteers (15 healthy non-smokers [NS] and 15 healthy smokers [S]) were included in the randomized, double-blind, placebo-controlled, crossover study. Varenicline (2 mg single dose) or placebo was administered in two different testing sessions (5 days after the first period, performed the second period). Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were assessed in the supine position and during handgrip exercise before and after the participants were given placebo or varenicline. Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were calculated from continuous ECG recordings and averages were used in the final analysis.
  
  
  RESULTS
  There were no statistically significant differences among any of the Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio before and after placebo administration in both groups (S and NS). In the S group, Tp-e and QTc interval, and Tp-e/QT and Tp-e/QTc ratio were significantly increased after varenicline administration (Tp-e: 64.28 ± 8.78 vs. 70.42 ± ± 13.12; p = 0.02, QTc: 409.57 ± 28.17 vs. 425.28 ± 32.79; p = 0.02, Tp-e/QT: 0.18 ± 0.02 vs. 0.19 ± 0.03; p = 0.04, Tp-e/QTc: 0.17 ± 0.02 vs. 0.19 ± 0.02; p = 001) but these parameters were not changed in the NS group.
  
  
  CONCLUSIONS
  Tp-e and QTc interval, and Tpe/QT and Tpe/QTc ratio were increased after varenicline administration in smokers.
authors.affiliation: Bursa Postgraduate Hospital, Depar tment of Cardiology, Bursa, Turkey. hasanari03@yahoo.com.
authors.forename: Hasan
authors.initials: H
authors.lastname: Ari
authors.forename: Selma
authors.initials: S
authors.lastname: Ari
authors.forename: Selvi
authors.initials: S
authors.lastname: Coşar
authors.forename: Nuran
authors.initials: N
authors.lastname: Celiloğlu
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Aktaş
authors.forename: Sencer
authors.initials: S
authors.lastname: Camci
authors.forename: Kübra
authors.initials: K
authors.lastname: Doğanay
authors.forename: Ahmet
authors.initials: A
authors.lastname: Tütüncü
authors.forename: Mehmet
authors.initials: M
authors.lastname: Melek
mesh_terms: D000200:Action Potentials; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004562:Electrocardiography; D005260:Female; D064368:Healthy Volunteers; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D018722:Nicotinic Agonists / Q000009:adverse effects*; D018570:Risk Assessment; D012907:Smoking / Q000503:physiopathology; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention; D013997:Time Factors; D061485:Tobacco Use Cessation Devices / Q000009:adverse effects*; D014421:Turkey; D000068580:Varenicline / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D018722:Nicotinic Agonists; D000068580:Varenicline
keywords: QT interval; Tp-e interval; varenicline