Can haloperidol be administered after Geodon (ziprasidone)?

Administration of Haloperidol After Ziprasidone (Geodon)

Haloperidol can be administered after ziprasidone (Geodon), but caution is warranted due to the potential for additive QT prolongation effects and increased risk of extrapyramidal symptoms.

QT Interval Considerations

• Both medications can prolong the QT interval, though to different degrees:

  • Ziprasidone (Geodon) causes QT prolongation of 5-22 ms 1
  • Haloperidol causes more modest QT prolongation of approximately 7 ms 1

• When transitioning between these medications, consider:

  • The half-life of ziprasidone (7 hours) to allow for adequate clearance
  • Monitoring ECG if the patient has other risk factors for QT prolongation
  • Avoiding other QT-prolonging medications during the transition

Dosing Recommendations

When administering haloperidol after ziprasidone:

1. Start with a lower dose of haloperidol:

   • 0.5-1 mg PO or SC for initial dosing 1
   • Use even lower doses (0.25-0.5 mg) in older or frail patients 1

2. Monitor closely for:

   • QT interval prolongation on ECG
   • Extrapyramidal symptoms (EPS), which are more common with haloperidol than with ziprasidone 2, 3
   • Excessive sedation

Clinical Evidence

Research comparing these medications has shown:

• Ziprasidone is associated with a lower incidence of movement disorders compared to haloperidol 2
• In a randomized study, haloperidol-treated patients exhibited significantly greater increases in Extrapyramidal Symptom Rating Scale scores compared to ziprasidone 3
• A study examining high-dose intramuscular injections found that both medications caused only modest changes in QTc interval, with none of the patients experiencing QTc intervals >480 msec 4

Special Considerations

• Timing: Allow at least 4-6 hours after the last dose of ziprasidone before administering haloperidol to minimize potential drug interactions
• Route of administration: Intramuscular route is preferred over intravenous for haloperidol due to FDA warnings about IV administration 1
• Monitoring: Observe for signs of sedation, which often precedes respiratory depression 1
• Anticholinergic medication: Consider having anticholinergic medication available to manage potential extrapyramidal symptoms, which are more common with haloperidol 2

Contraindications

Avoid this combination or use with extreme caution in patients with:

• Known QT prolongation
• History of torsades de pointes
• Congenital long QT syndrome
• Recent myocardial infarction
• Uncompensated heart failure
• Concurrent use of other QT-prolonging medications

By following these guidelines, haloperidol can be safely administered after ziprasidone while minimizing the risk of adverse effects and maintaining effective symptom control.