Effects of newer atypical antipsychotics on autonomic neurocardiac function: A comparison between amisulpride, olanzapine, sertindole, and clozapine

As part of a prospective clinical study investigating the effects of atypic al neuroleptics on autonomic neurocardiac function (ANF), serial standardiz ed recordings of conventional electrocardiograms and computer-calculated me asurements of 5-minute resting heart rate variability (HRV) were obtained f rom 51 medication-free inpatients with schizophrenia (DSM-III-R-diagnosed) before and after an average of 14.1 days of treatment with amisulpride 400 mg/day (N = 12), olanzapine 20 mg/day (N = 13), sertindole 12 mg/day (N = 1 3), or clozapine 100 mg/day (N = 13). Reference values for the HRV data wer e obtained from a large group of web-matched healthy controls (N = 70). The most important findings were the following: (1) clozapine, olanzapine, and sertindole all prolonged mean frequency-corrected QTc times, which, in the case of sertindole, proved to be significant (Wilcoxon test p < 0.05); (2) sertindole and clozapine significantly increased the mean resting heart ra te; and (3) only clozapine significantly reduced the parasympathetic restin g tone, The results of the HRV studies are discussed considering the in vit ro receptor profiles of the atypical neuroleptics under study. Potential im plications for the cardiac safety and tolerance of these drugs are also dis cussed.