Antipsychotics are associated with the polymorphic ventricular tachycardia, Torsade's de pointes, which in worst case can lead to sudden cardiac death. The QTc interval is used as a clinical proxy for Torsade's de pointes. QTc interval is prolonged by monotherapy with antipsychotic, but it is unknown if the QTc interval is prolonged further with antipsychotic polypharmacy.
To investigate the associations between QTc interval and antipsychotic mono- and polypharmaceutical treatment, respectively, in schizophrenic patients.
To learn more about the impact of antipsychotics on the QTc interval.
An observational cohort study of unselected patients with schizophrenia visiting outpatient facilities in the Region of Central Jutland, Denmark. Patients were enrolled from January 2013 through March 2015 with follow-up until June 2015. Data was collected from clinical interviews and clinical case records.
ECGs were available in 58 patients receiving antipsychotic treatment. We observed no difference in average QTc interval for the whole sample of patients receiving monotherapy or polypharmacy (P = 0.29). However, women presented longer QTc-interval on polypharmacy than on monotherapy (P = 0.01).
We recommend an increased focus on monitoring the QTc interval in woman with schizophrenia receiving antipsychotics as polypharmacy.
The authors have not supplied their declaration of competing interest.