Psych

Droperidol

Rapid Review

  • Mechanism of Action: Antipsychotic, Antiemetic; antagonizes dopamine and alpha adrenergic receptors. 
  • Indications: Agitation, nausea/vomiting, headache, pain (as adjunct w/ opiate) 
  • Contraindications: Allergy to drug/class, known or suspected prolonged QT
  • Dosage:
    • Acute agitation: 5-10mg (IV) or 10 mg (IM)
    • Nausea/vomiting: 0.625 – 2.5 mg (IV)
  • Onset: 5-10 minutes
  • Duration: 2-4 hours
  • Adverse Reactions: QT prolongation, extrapyramidal side effects

Pearls

  • Obtaining an EKG prior to administering droperidol is recommended when possible due to concern for QT prolongation.
  • Droperidol has a much faster onset than haloperidol, making it the agent of choice for acute agitation. 
Video Credit: ER-Rx Podcast

Haloperidol

Rapid Review

  • Mechanism of Action: Antipsychotic; blocks dopaminergic receptors in the brain, depressing reticular activating system.
  • Indications: Acute agitation, psychosis
  • Contraindications: Allergy to drug, Parkinson’s disease. Caution in QT prolongation.
  • Dosage: 5-10 mg PO/IM/IV q2hrs (Max 100mg/day)
  • Onset: 10-20 minutes
  • Duration: 4-6 hours (IV)
  • Adverse Reactions: Drowsiness, extrapyramidal symptoms, tardive dyskinesia
  • Special Considerations: May increase liver function test values

Pearls

  • Haloperidol has strong antiemetic properties and is particularly effective in treating cannabinoid hyperemesis syndrome. 
  • When possible, you should always get an EKG prior to administration of haloperidol given it’s QTc prolonging effects. 
Video Credit: Nurse Ryan

Olanzapine

Rapid Review

  • Mechanism of Action: Atypical antipsychotic; binds to dopamine, histamine, alpha1, and 5HT2 receptors. 
  • Indications: Acute agitation, schizophrenia, bipolar disorder
  • Contraindications: Allergy to drug/class. Should not be given for dementia-related psychosis, NMS
  • Dosage: 5-10 mg IM/ODT (max 30mg/day)
  • Onset: 15-45 minutes
  • Duration: Half life of 30 hours for most adults
  • Adverse Reactions: Orthostatic hypotension (3-20%), Neuroleptic malignant syndrome, extrapyramidal side effects
  • Special Considerations: N/A

Pearls

  • Olanzapine is considered safer than other antipsychotics due to it’s lower risk of extrapyramidal side effects and it’s minimal impact on QTc. When combined with benzodiazepines though, this can increase overall risk of respiratory depression.
  • Although olanzapine is effective for acute agitation, it does require reconstitution which may delay it’s administration time. This may be problematic for the severely agitated or violent patient.
Video Credit: Nurse Ryan

Ziprasidone

Rapid Review

  • Mechanism of Action: Antipsychotic; D2 and 5HT2 antagonist. Strong alpha 1 blocker and histamine-1 antagonist.
  • Indications: Acute agitation, psychosis.
  • Contraindications: QT prolongation, allergy to drug, decompensated heart failure
  • Dosage: 10-20mg IM q2-4 hrs (Max: 40 mg/day)
  • Onset: 
  • Duration: Half life 2-7 hrs.
  • Adverse Reactions: Prolonged QT, torsades, neuroleptic malignant syndrome, extrapyramidal side effects, dizziness
  • Special Considerations: None 

Pearls

  • Ziprasidone tends to have a faster onset of action, reduced extrapyramidal symptoms, and superior efficacy over typical antipsychotics such as haloperidol. However, it does prolong the QTc interval more than any other antipsychotic agents.
  • For the undifferentiated agitated patient, benzodiazepines (ex. midazolam) are the drugs of choice. For agitation caused by known psychosis, intoxication, or sundowning, agents like ziprasidone are better options.
Video Credit: Eric Christianson