Background: Since the 2001 "black box" warning on droperidol, its use in the prehospital setting has decreased substantially in favor of haloperidol. There are no studies comparing the prehospital use of either drug. The goal of this study was to compare QTc prolongation, adverse events, and effectiveness of droperidol and haloperidol among a cohort of agitated patients in the prehospital setting.
Methods: In this institutional review board-approved before and after study, we collected data on 532 patients receiving haloperidol (n = 314) or droperidol (n = 218) between 2007 and 2010. We reviewed emergency department (ED) electrocardiograms when available (haloperidol, n = 78, 25%; droperidol, n = 178, 76%) for QTc length (in milliseconds), medical records for clinically relevant adverse events (defined a priori as systolic blood pressure (SBP) <90 mmHg, seizure, administration of anti-dysrhythmic medications, cardioversion or defibrillation, bag-valve-mask ventilation, intubation, cardiopulmonary arrest, and prehospital or in-hospital death). We also compared effectiveness of the medications, using administration of additional sedating medications within 30 minutes of ED arrival as a proxy for effectiveness.
Results: The mean haloperidol dose was 7.9 mg (median 10 mg, range 4-20 mg). The mean droperidol dose was 2.9 mg (median 2.5 mg, range 1.25-10 mg.) Haloperidol was given i.m. in 289 cases (92%), and droperidol was given i.m. in 132 cases (61%); in all other cases, the medication was given i.v.. There was no statistically significant difference in median QTc after medication administration (haloperidol 447 ms, 95% CI: 440-454 ms; droperidol 454 ms, 95% CI: 450-457). There were no statistically significant differences in adverse events in the droperidol group as compared to the haloperidol group. One patient in the droperidol group with a history of congenital heart disease suffered a cardiopulmonary arrest and was resuscitated with neurologically intact survival. There was no significant difference in the use of additional sedating medications within 30 minutes of ED arrival after receiving droperidol (2.9%, 95% CI: -2.5-8.4%).
Conclusions: In this cohort of agitated patients treated with haloperidol or droperidol in the prehospital setting, there was no significant difference found in QTc prolongation, adverse events, or need for repeat sedation between haloperidol and droperidol.
Keywords: droperidol; emergency medical services; haloperidol.