Send to

Choose Destination
See comment in PubMed Commons below
Pharmacoepidemiol Drug Saf. 2015 Jul;24(7):701-8. doi: 10.1002/pds.3792. Epub 2015 May 27.

Are ECG monitoring recommendations before prescription of QT-prolonging drugs applied in daily practice? The example of haloperidol.

Author information

  • 1Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
  • 2Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.



Monitoring of the QT duration by electrocardiography (ECG) prior to treatment is frequently recommended in the label of QT-prolonging drugs. It is, however, unknown how often general practitioners in daily clinical practice are adhering to these risk-minimization measures. We assessed the frequency of ECG measurements in patients where haloperidol was initiated in primary care.


Patients (≥18 years) with a first prescription of haloperidol in the UK Clinical Practice Research Datalink (2009-2013) were included. The proportion of ECGs made was determined in two blocks of 4 weeks: during the exposure period when haloperidol was initiated, and during the control period, 1 year before. Conditional logistic regression analysis was applied to calculate the relative risk of having an ECG in the exposure period compared with the control period. Subgroup analyses were performed to assess the proportion of ECG measurements in patients with one or more additional risk factors for QT prolongation.


In total, 3420 patients were prescribed haloperidol during the exposure period, and 1.8% of them had an ECG at treatment initiation, compared with 0.8% during the control period (relative risk [RR] 2.4 [1.5-3.8]). Of the patients with additional risk factors for QT prolongation, 1.9% of the patients had an ECG at initiation of the prescription, compared with 1.0% during the control period (RR 2.1 [1.2-3.5]).


Compliance with recommendations to perform an electrocardiogram when starting a new QT-prolonging drug is extremely low, when haloperidol is taken as an example.


antipsychotic agent; cardiac arrhythmia; communication; epidemiology; pharmacoepidemiology; regulatory; risk minimization

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center