Single-dose ziprasidone associated with QT interval prolongation

Ziprasidone has been rarely associated with QT prolongation especially in patients (1) with no underlying cardiac or metabolic disorders, (2) who are receiving no concomitant medications known to prolong the QT interval, and (3) whom therapy is being initiated at a low dose. We report a 47-year-old patient who was agitated with suicidal ideation. He had a history of cocaine use, the last time being 72 hours before emergency department (ED) presentation. His electrocardiogram (ECG) on arrival in the ED showed a QT of 484 milliseconds and a QTc of 475 milliseconds with a pulse of 58 beats per minute. The patient was given 20 mg intramuscular (IM) ziprasidone for agitation. He reported feeling palpitations and weakness 45 minutes after receiving ziprasidone. His QT interval was prolonged on ECG and returned to baseline after 72 hours. Clinicians should consider obtaining an ECG before ziprasidone administration.