TABLE 1

Antipsychotic agents

AgentHaloperidolOlanzapineQuetiapineRisperidoneAripiprazole
Dosage formsOral tablets, solution
Intramuscular and intravenous solutions
Oral tablets, disintegrating tablets
Intramuscular solution
Oral tablets, solutionOral tablets, disintegrating tablets, solutionOral tablets, solution, distintegrating tablets
Intramuscular solution
Starting dose0.5–1 mg twice a day2.5–5 mg twice a day12.5–25 mg twice a day0.5 mg twice a day1 mg twice a day
Half-life (hours)12–3821–5462075
ClearanceHepaticHepaticHepaticHepaticHepatic
Common adverse effectsAkathisia Dystonia ParkinsonismAkathisia ParkinsonismAgitationParkinsonismAkathisia Agitation
Effects on corrected QT intervalOral, intramuscular: Mild
Intravenous: Moderate
MildMildMildNone
Orthostatic hypotensionMildModerateSevereSevereModerate
Anticholinergic effectsaMildSevereModerateMildMild
SedationMildModerateSevereModerateModerate
Drug-drug interactions (CYP450 activity)Substrate of: CYP1A2 (minor) CYP2D6 (major) CYP3A4 (major)
Inhibits CYP2D6 (moderate)
Substrate of: CYP1A2 (major) CYP2D6 (minor)Substrate of: CYP2D6 (minor) CYP3A4 (major)Substrate of: CYP2D6 (major) CYP3A4 (minor)Substrate of: CYP2D6 (major) CYP3A4 (major)
Special considerationsMinimal effect on vital signs
May worsen stiffness and motor symptoms in Parkinson disease
Comes in dissolvable form
Helpful for cancer-related nausea
Do not combine with parenteral benzodiazepines due to risk of respiratory depression
May worsen control of diabetes
Consider in Parkinson diseaseComes in dissolvable formMay be useful for hypoactive delirium
No known effect on QTc
  • a Dry mouth, constipation, urinary retention.

  • Based on information from references 2325.