EPV1334 - Clozapine levels in hospitalised schizophrenic patients does not predict re-hospitalisation: a naturalistic study.

EPV1334

Clozapine levels in hospitalised schizophrenic patients does not predict re-hospitalisation: a naturalistic study.

A. M. Mach ^1,*, P. Bieńkowski ¹, A. Wnorowska ¹, M. Sypniewski ², M. Radziwoń-Zaleska ¹, M. Wojnar ^{1 3}

¹Department of Psychiatry, Medical University of Warsaw, Warsaw, ²2Greater Poland Center of Digital Medicine, Poznan University of Medical Sciences, Poznan, Poland, ³Department of Psychiatry, Addiction Center, University of Michigan, Ann Arbor, MI 48109, United States

 

Introduction: Clozapine (CLO) is an atypical antipsychotic drug effective in the management of treatment-resistant schizophrenia and prevention of relapses in ambulatory care. Therapeutic drug monitoring (TDM) is the recommended method for personalised CLO dose titration.

Objectives: The aim of this real-life study was to assess whether CLO and norclozapine (NCLO) concentrations at the time of hospitalisation could predict the risk of psychiatric re-hospitalisation during outpatient care.

Methods: A total of 141 blood samples (71 females and 70 males, aged from 18 to 74 years) were analysed for serum CLO and NCLO levels with high-performance liquid chromatography coupled with a UV detector. All the patients received inpatient and outpatient care in a single academic psychiatric center from 2016 to 2022. The occurrence of re-hospitalisation was assessed for each patient up to 360 days. 

Results: At all analysed time intervals (90, 180, 360 days), no correlation was observed between either CLO or NCLO concentrations and the risk of psychiatric re-hospitalisation. Patients on CLO monotherapy presented a significantly lower risk of re-hospitalisation at 180-day and 360-day follow-up (p<0.001) as compared to patients receiving CLO in combination with other psychotropic medications. The risk of re-hospitalisation was increased in patients with a higher number of previous psychiatric hospitalisations (OR =1.15, p<0.01) and in patients taking one or more psychotropic medications other than clozapine (OR=1.51, p<0.05). 

Conclusions: Our study suggest that: 1) in-hospital, steady-state CLO or NCLO levels do not predict the risk of psychiatric re-hospitalisation after discharge; 2) the use of CLO in polytherapy with other psychotropic medications and the number of previous psychiatric hospitalisations may increase the risk of re-hospitalisation.

 

Disclosure of Interest: None Declared