Association of autonomic dysfunction and clozapine
BackgroundAntipsychotic medications cause a wide range of adverse effects and have been associated with sudden death in psychiatric patients.AimsTo supply power spectral analysis of heart rate variability as a tool to examine the arrythmogenic effects of neuroleptics.MethodHeart rate analysis was carried out in patients with schizophrenia on standard doses of neuroleptic monotherapy − 21 were on clozapine, 18 on haloperidol and 17 on olanzapine – and in 53 healthy subjects.ResultsPatients with schizophrenia on clozapine had significantly higher heart rate, lower heart rate variability and lower high-frequency and higher low-frequency components compared with patients on haloperidol or olanzapine and matched control subjects. Prolonged QTc intervals were more common in patients than controls.ConclusionsPatients treated with neuroleptic medications, especially clozapine, showed autonomic dysregulation and cardiac repolarisation changes. Physicians should be aware of this adverse reaction.