46 patients treated with high-dose droperidol (10-40 mg) were studied prospectively with continuous holter recording.
What they did
Patients initially received 10 mg droperidol as part of a standardized sedation protocol (for aggression). An additional 10 mg dose was given after 15 min if required and further doses at the clinical toxicologist's discretion.
Continuous 12-lead holter recordings were obtained for 2-24 hours. QTc > 500 msec was defined as abnormal (with heart rate correction - QTcF).
What they found
Only 4 patients had abnormal QT measurements, three given 10 mg and one 20 mg. All 4 had other reasons for QT prolongation. No patient given > 30 mg had a prolonged QT. There were no dysrhythmias.
What it means
There was little evidence supporting droperidol being the cause and QT prolongation was more likely due to pre-existing conditions or other drugs.
References
Calver L, et al. High dose droperidol and QT prlongation: analysis of continuous 12-lead recordings. Br J Clin Pharmacol. 2014;77(5):880-6. [PMID 24168079]
