CORRELATION BETWEEN PLASMA CLOZAPINE CONCENTRATION AND HEART-RATE-VARIABILITY IN SCHIZOPHRENIC-PATIENTS

Forty schizophrenic patients treated with 50-600 mg/day of clozapine a s monotherapy and 40 normal control subjects were tested for heart rat e variability (HRV) which is mediated by the vagus nerve using acetylc holine as neurotransmitter. As compared to the control subjects, the p atients showed essentially reduced HRV parameters which were negativel y correlated with the plasma clozapine levels. Therefore, clozapine's anticholinergic effect is correlated to the plasma clozapine level whe n measured by the decrease of HRV We suggest that HRV data might be us eful as a predictor for plasma clozapine levels.