Differential Changes in QTc Duration during In-Hospital Haloperidol Use

Aims: To evaluate changes in QT duration during low-dose haloperidol use, and determine associations between clinical variables and potentially dangerous QT prolongation. Methods: In a retrospective cohort study in a tertiary university teaching hospital in The Netherlands, all 1788 patients receiving haloperidol between 2005 and 2007 were studied; ninety-seven were suitable for final analysis. Rate-corrected QT duration (QTc) was measured before, during and after haloperidol use. Clinical variables before haloperidol use and at the time of each ECG recording were retrieved from hospital charts. Mixed model analysis was used to estimate changes in QT duration. Risk factors for potentially dangerous QT prolongation were estimated by logistic regression analysis. Results: Patients with normal before-haloperidol QTc duration (male <= 430 ms, female <= 450 ms) had a significant increase in QTc duration of 23 ms during haloperidol use; twenty-three percent of patients rose to abnormal levels (male >= 450 ms, female >= 470 ms). In contrast, a significant decrease occurred in patients with borderline (male 430-450 ms, female 450-470 ms) or abnormal before-haloperidol QTc duration (15 ms and 46 ms, respectively); twenty-three percent of patients in the borderline group, and only 9% of patients in the abnormal group obtained abnormal levels. Potentially dangerous QTc prolongation was independently associated with surgery before haloperidol use (OR(adj) 34.9, p = 0.009) and before-haloperidol QTc duration (OR(adj) 0.94, p = 0.004). Conclusion: QTc duration during haloperidol use changes differentially, increasing in patients with normal before-haloperidol QTc duration, but decreasing in patients with prolonged before-haloperidol QTc duration. Shorter before-haloperidol QTc duration and surgery before haloperidol use predict potentially dangerous QTc prolongatio

Correction: Differential Changes in QTc Duration during In-Hospital Haloperidol Use

[This corrects the article on p. e23728 in vol. 6.

Baseline characteristics of patients: all, and stratified in subgroups based on QTc duration before haloperidol.

<p>Normal QTc duration: male <430 ms, female <450 ms,; borderline QTc duration: male 431–450 ms, female 451–470 ms;</p><p>abnormal QTc duration: male >450 ms, female >470 ms.</p><p>*Significant differences between subgroups (p<0.05).</p

Unadjusted and adjusted Odds Ratios for potentially dangerous QTc prolongation.

<p>OR: Odds Ratio, CI: confidence interval, SD: Standard Deviation, n.a.: not applicable.</p><p>*Multivariate I: ORs in the multivariate analysis are adjusted for gender, baseline QTc duration in ms, heart rate, surgery before haloperidol, and signs of inflammation.</p

Flowchart of patient inclusion.

<p>Flowchart of patient inclusion.</p

Course of changes in QTc duration before, during and after haloperidol use.

<p>Mean QTc intervals before, during and after haloperidol use of total patient group and of each subgroup, with Standard Errors of the mean. Normal: male ≤430 ms, female ≤450 ms, borderline: male 431–450 ms, female 451–470 ms, abnormal: male >450 ms, female >470 ms. B: before haloperidol use, D: during haloperidol use, A: after haloperidol use. * indicates significant change at p<0.05 level.</p