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Droperidol : Dangerous Drug or Hazard Hyperbole?. Todd Severson April 22, 2003. Droperidol: The Drug. Rapid-acting, high-potency butyrophenone Dopamine antagonist & mild -adrenergic blockade Used for: Anti-emetic properties Tranquilization of agitated patients
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Droperidol: Dangerous Drug or Hazard Hyperbole? Todd Severson April 22, 2003
Droperidol: The Drug • Rapid-acting, high-potency butyrophenone • Dopamine antagonist & mild -adrenergic blockade • Used for: • Anti-emetic properties • Tranquilization of agitated patients • Treatment of acute migraine headache
Droperidol: The Issue • Widespread use in the U.S. since 1970 • Case reports of QT prolongation and torsades • FDA “black-box” warning December 2001: • “Due to its potential for serious proarrhythmic effects and death, INAPSINE should be reserved for use in the treatment of patients who fail to show an acceptable response to other adequate treatments…” • Is the warning appropriate? Can droperidol be used?
Droperidol QT effect • Droperidol does prolong the QT interval in dose-response fashion • Lischke et al, Anesth Analg, 1994: • Prospective, randomized, double-blind study of 40 healthy patients undergoing elective surgery • Three dose levels of pre-induction droperidol given IV • Serial EKG’s showed rapid onset of QT prolongation, dose related, (37 / 44 / 59 ms), not increased with time
Droperidol QT effect • Similar results by Guy et al (Ann Cardiol Angeiol, 1991) prospective observational study of 55 elective surgery patients receiving 0.25mg/kg IV droperidol • Retrospective review by Smith et al (Acad Emerg Med, 2002) of 15,374 ED patients over 4 years showed 3.1% incidence of QT > 480ms in patients who had received droperidol
Droperidol dysrhythmia effect • Five published systematic reviews of droperidol use as an anti-emetic; no adverse cardiac events reported • Seven published case reports of adverse cardiac events associated with droperidol use, many with confounding factors (e.g., other drugs, hypokalemia)
Droperidol dysrhythmia effect • Published FDA literature (McCormick, Am Soc Anesth Newsletter) lists approximately 100 reports of adverse cardiac events, 38 analyzed in detail: • 12 events with droperidol dose 2.5mg • 11 events within 30 minutes of droperidol administration • Unpublished MedWatch reports, 273 cases: • 42 dysrhythmias, 10 fatal • Droperidol primary suspect drug in 12 of 29 cases 5mg
Causation? • Is droperidol use an independent risk factor for sudden cardiac death? • Data does show droperidol prolongs the QT interval in a dose-related fashion • However, data does not support the transitive conclusion that droperidol use therefore leads to cardiac death. Such events are rare.
Conclusions • Caution is clearly warranted in using droperidol • A “black-box” warning seems excessive based on available evidence (i.e., judicious use as an initial therapy is appropriate in selected patients) • Ongoing study is needed, but will likely be severely limited by decreased use of the drug in response to the black box warning and litigation concerns
HUP-isms • Droperidol is a reasonable drug choice in the appropriate context • You’ll never use it