Longitudinal ECG changes in cocaine users during extended abstinence

Drug Alcohol Depend. 2008 May 1;95(1-2):160-3. doi: 10.1016/j.drugalcdep.2007.12.001. Epub 2008 Feb 1.


Background: Cocaine lengthens electrocardiographic QTc, QRS and PR intervals through blockade of sodium and potassium channels, but changes during withdrawal have not been well studied.

Methods: We recorded weekly electrocardiograms (ECGs) from 25 physically healthy cocaine users (84.0% men, mean [S.D.] age 34.7 [4.1] years, 9.0 [5.2] years of cocaine use, 9.4 [3.5] days of use in the 2 weeks prior to admission) over 3 months of monitored abstinence on a closed ward. Subjects had minimal current use of other drugs. Baseline ECGs were recorded 20.5 h [16.6] after last cocaine use.

Results: Baseline QTc interval correlated positively with total amount of cocaine used and amount used per day in the 2 weeks prior to ward admission. There was a significant 10.5 ms [12.9] shortening of QTc interval during the first week of withdrawal, with no further significant changes thereafter. There were no significant changes in PR or QRS intervals.

Conclusions: These findings suggest that cocaine-associated QTc prolongation returns toward normal during the first week of cocaine abstinence.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • Cocaine / toxicity*
  • Cocaine-Related Disorders / rehabilitation*
  • Dose-Response Relationship, Drug
  • Electrocardiography / drug effects*
  • Female
  • Follow-Up Studies
  • Heart Conduction System / drug effects*
  • Heart Conduction System / physiopathology
  • Humans
  • Long QT Syndrome / physiopathology
  • Long QT Syndrome / rehabilitation
  • Male
  • Substance Withdrawal Syndrome / physiopathology*


  • Cocaine