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Single-dose ziprasidone associated with QT interval prolongation
Joanne C Witsil1, Michele Zell-Kanter, Mark B Mycyk
1Department of Pharmacy, Cook County Hospital (Stroger), TOXIKON Consortium, Chicago, Ill 60612, USA. jwitsil@ccbh.org
The American Journal of Emergency Medicine
|June 7, 2011
Summary
Ziprasidone can rarely cause QT prolongation, even in patients without risk factors. This case highlights the importance of electrocardiogram (ECG) monitoring before administering ziprasidone.
Area of Science:
- Pharmacology
- Cardiology
- Psychiatry
Background:
- Ziprasidone is an atypical antipsychotic used for agitation and psychosis.
- QT prolongation is a rare but serious side effect associated with ziprasidone.
- Risk factors for QT prolongation typically include pre-existing cardiac conditions, concurrent QT-prolonging medications, and higher initial doses.
Observation:
- A 47-year-old male with a history of cocaine use presented with agitation and suicidal ideation.
- Initial electrocardiogram (ECG) showed a QT interval of 484 ms and QTc of 475 ms.
- The patient received 20 mg intramuscular ziprasidone for agitation.
Findings:
- 45 minutes post-administration, the patient experienced palpitations and weakness.
- ECG revealed QT interval prolongation after ziprasidone administration.
- The QT interval normalized within 72 hours.
Implications:
- This case suggests ziprasidone can induce QT prolongation even in patients without typical risk factors.
- Clinicians should consider baseline ECG assessment before ziprasidone administration.
- Further vigilance is warranted for patients with a history of substance use.
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