David A. Flockhart

School of Medicine, Medicine, Clinical Pharmacology

Scopus Publication Detail

The publication detail shows the title, authors (with indicators showing other profiled authors), information on the publishing organization, abstract and a link to the article in Scopus. This abstract is what is used to create the fingerprint of the publication.

Intramuscular haloperidol or lorazepam and QT intervals in schizophrenia

Anne T. Harvey; David Flockhart; J. Christopher Gorski; David J. Greenblatt; Michael Burke; Steve Werder; Sheldon H. Preskorn (Profiled Author: David A. Flockhart)

Journal of Clinical Pharmacology. 2004;44(10):1173-1184.

The objective of this study was to estimate the effects of intramuscular haloperidol and lorazepam on the QT interval in volunteers with schizophrenia. Intramuscular haloperidol and intramuscular lorazepam are standard treatments in the acute management of agitation and aggression. Although prolongation of the QT interval and sequelae, including torsade de pointes and death, have been reported for haloperidol (but not lorazepam), formal studies have been lacking. Volunteers with schizophrenia (n = 12) were administered a single intramuscular injection of 7.5 mg haloperidol or 4 mg lorazepam in a blinded, randomized, placebo-controlled crossover design. Serial EKGs and concurrent blood samples were obtained over 6 hours following each injection. Changes in the QT interval were evaluated, as were plasma drug and prolactin concentrations. Haloperidol injection increased the heart rate-corrected QT interval an average of 5.1 msec using Bazett's correction (QT b 90% confidence interval [CI]: 0.3, 9.8), 3.6 msec using Fridericia's correction (QT f 90% CI: 0.02, 7.2), and 4.2 msec using an empirically derived "baseline correction" (QT ⁱⁱ 90% CI: 0.3, 8.0). Effects of lorazepam on QT were nullified by correction for the heart rate elevation (QT b 3.8 msec, 90% CI: 0.6, 7.1; QT f 0.0 msec, 90% CI:-3.2, 3.4; QT ii-2.3 msec, 90% CI:-6.6, 2.0). An association between QT prolongation and occurrence of extrapyramidal symptoms was observed. On average, intramuscular haloperidol led to minimal prolongation of the QT interval. This propensity is of theoretical concern in individuals with risk factors for torsade de pointes but seems unlikely to be a problem in the vast majority of patients.

PMID: 15342619    

Scientific Context

This section shows information related to the publication - computed using the fingerprint of the publication - including related publications, related experts with fingerprints representing significant amounts of overlap between their fingerprint and this publication. The red dots indicate whether those experts or terms appear within the publication, thereby showing potential and actual connections.