Clozapine antipsychotic polypharmacy: audit of use and patient monitoring

Aims and method We audited prescribing within our area to ascertain how widespread the practice of antipsychotic polypharmacy using clozapine was, and whether it was being carried out within existing standards, including those of high-dose monitoring when required. Results Data on 169 patients were reviewed in year one, rising to 193 in year three. Around 30% of patients on clozapine received additional antipsychotic medication. A disturbingly low proportion of patients on clozapine whose antipsychotic polypharmacy brought them into the high-dose range were being monitored appropriately after three audit cycles (the proportion rose from 10% in cycle 1 to 28% in cycle 3). A wide range of additional antipsychotic medications was used. Clinical implications Clozapine antipsychotic polypharmacy was prevalent at just below a third of all patients in this review. Prescribers should be alert to the fact that clozapine antipsychotic polypharmacy can push patients into the high-dose range and ensure appropriate monitoring.