Symptomatic bradycardia with oral aripiprazole and oral ziprasidone

To describe the case of a patient who developed symptomatic bradycardia upon initiation of oral ziprasidone and later with oral aripiprazole, both of which resolved shortly after discontinuation of therapy.

An 18-year-old female with bipolar disorder was started on oral ziprasidone 80 mg at night and the dose was subsequently increased to 120 mg for management of acute mania and delusions. The patient developed symptomatic bradycardia (heart rate 31-35 beats/min), which resolved after ziprasidone was decreased to 80 mg. Three months later, the patient was readmitted for treatment of bipolar mania with psychotic features in the context of medication nonadherence. She was started on oral aripiprazole 15 mg daily (subsequently increased to 20 mg) in conjunction with 600 mg lithium carbonate twice daily. The patient again developed symptomatic bradycardia that resolved after discontinuation of aripiprazole.

This is the first case report of symptomatic bradycardia associated with the use of ziprasidone or aripiprazole. The Naranjo probability scale suggests that the likelihood of the atypical antipsychotic as the cause of bradycardia is probable for both ziprasidone and aripiprazole. Symptomatic bradycardia with the use of other atypical antipsychotics has been reported in the literature. Little is known about the mechanisms that contribute to the antipsychotic-associated bradycardic response.

Further studies are needed to better determine the relationship between antipsychotics and reflex bradycardia. Although bradycardia remains a relatively uncommon phenomenon seen with the use of these medications, the severity of this potential adverse effect warrants consideration when initiating antipsychotic therapy.