Antipsychotic polypharmacy and clozapine prescribing patterns: evolution
and correlates before and after a psychiatric hospitalisation
Abstract
Aim: To explore the evolution of antipsychotic polypharmacy (APP) and
other psychotropic prescribing patterns during psychiatric
hospitalisations, to detect characteristics associated with APP on
admission and at discharge, and to examine clozapine prescribing
patterns. Methods: Data on adult inpatients diagnosed with schizophrenia
spectrum disorders were collected retrospectively from 6 Belgian
hospitals. Results: Of the 516 patients included, APP prescribing
increased significantly from 47.9% on hospital admission to 59.1% at
discharge. On admission and at discharge, APP was associated with prior
clozapine use (ORadmission=2.53, CI=1.1-5.84, ORdischarge=11.01,
CI=4.45-27.28), treatment with a first-generation antipsychotic
(ORadmission=26.79, CI=13.08-54.86, ORdischarge=25.2, CI=12.2-52.04),
increased antipsychotic exposure (ORadmission=8.93, CI=5.13-15.56,
ORdischarge=19.89, CI=10-39.54), and a greater number of hypno-sedatives
(ORadmission=1.88, CI=1.23-2.88, ORdischarge=4.18, CI=2.53-6.91), and
negatively associated with involuntary admission (ORadmission=0.31,
CI=0.14-0.7, ORdischarge=0.3, CI=0.13-0.68). When using an alternative
definition of monotherapy (i.e., including patients with an add-on
low-dose antipsychotic for sleep disorders), alcohol use disorder
(ORadmission=0.26, CI=0.13-0.54) and higher age (ORdischarge=0.53,
CI=0.29-0.95) were negatively associated with APP, and living in a
residential facility (ORdischarge=2.39, CI=1.21-4.71) and a higher daily
dosage of benzodiazepines during the stay (ORdischarge=1.32,
CI=1.03-1.69) increased the odds of being discharged on APP. Although
28.1% of patients were eligible for clozapine treatment, only 9.3%
were being treated with clozapine on admission, and 11% at discharge.
Seven of the ten patients with a new clozapine prescription were
directly being prescribed a combination of antipsychotics, without a
prior trial of clozapine monotherapy. Conclusion: Suboptimal
prescriptions of antipsychotics in patients with schizophrenia persist
after psychiatric hospitalisations and are associated with identifiable
characteristics.