From the Guidelines
No, droperidol is not an antihistamine. Droperidol is a neuroleptic (tranquilizer) agent, as described in the multisociety sedation curriculum for gastrointestinal endoscopy 1. It is used as an adjunct to standard sedation for complex endoscopic procedures or difficult-to-sedate patients, with an onset of action of 3 to 10 minutes and a duration of effect of 2 to 4 hours. The usual dose of droperidol for endoscopic sedation is 1.25 to 2.5 mg intravenously. Unlike antihistamines, which block histamine H1 receptors to treat allergic reactions, droperidol's mechanism involves blocking dopamine receptors, which helps control nausea and vomiting. It also has alpha-adrenergic blocking properties.
Key Points
- Droperidol carries a black box warning from the FDA regarding QT prolongation and risk of potentially fatal cardiac arrhythmias, so ECG monitoring is recommended when using this medication 1.
- Common side effects include sedation, hypotension, and extrapyramidal symptoms.
- The use of droperidol as an adjunct for endoscopic sedation should be avoided in most circumstances, especially in patients with a prolonged QTc interval or those at increased risk of developing QT interval prolongation 1.
Considerations
- The diagnosis and management of conditions such as rhinitis may involve the use of antihistamines, but droperidol is not an antihistamine and should not be used for this purpose 1.
- Second-generation antihistamines are generally preferred over first-generation antihistamines for the treatment of allergic rhinitis due to their lower likelihood of adverse effects.
From the FDA Drug Label
Possible pharmacodynamic interactions can occur between droperidol and potentially arrhythmogenic agents such as class I or III antiarrhythmics, antihistamines that prolong the QT interval, antimalarials, calcium channel blockers, neuroleptics that prolong the QT interval, and antidepressants
- Droperidol is not an antihistamine, but it can interact with antihistamines that prolong the QT interval.
- The FDA drug label does not classify droperidol as an antihistamine 2
From the Research
Droperidol Classification
- Droperidol is classified as a butyrophenone with antiemetic, sedative, anxiolytic, and analgesic properties 3.
- It is not classified as an antihistamine, but rather as a dopamine receptor antagonist 4.
Mechanism of Action
- Droperidol functions as an analgesic, sedative, and antiemetic by antagonizing dopamine receptors 4.
- Its mechanism of action does not involve antihistamine properties.
Clinical Uses
- Droperidol is used to treat nausea and vomiting, acute psychosis, migraine, and pain in the emergency department 3, 4, 5.
- It is not typically used as an antihistamine, but rather for its antiemetic, sedative, and analgesic effects.