Clozapine use and prevalence in Australia 2016-2020

Seven decades of antipsychotic drugs: Why is the life of Australians with schizophrenia still so suboptimal?

The advent of dopamine (D2) receptor-blocking medications over 70 years ago, ushered in a new era of biological treatment for schizophrenia. However, we argue that little subsequent progress has been made in translating this into fulfilled and fulfilling lives for people with schizophrenia. This Viewpoint asks why this is the case, and suggests ways forward for capitalising on extant and emerging new treatments for psychotic disorders, to the betterment of the lives of people living with schizophrenia.

Toxicity and Adverse Effects in Clozapine-Related Presentations to a Medical Toxicology Service in Western Sydney

BACKGROUND

Clozapine is an anti-psychotic agent, reserved for treatment-resistant schizophrenia, with demonstrated efficacy in an otherwise therapeutically challenging patient population. We aimed to review the full spectrum casemix of clozapine presentations to our tertiary toxicology service.

METHODS

In this retrospective study, we reviewed consecutive clozapine related toxicity presentations to a tertiary medical toxicology inpatient and consultation service-including deliberate self-poisoning (DSP), adverse drug reaction (ADR), recreational use, and therapeutic misadventure over a 10-year period from 2011 to 2021. Data were extracted for demographics, ingested dose, exposure characteristics, and patient outcome.

RESULTS

We identified 83 patients with clozapine-related presentations over the 10-year period. Twenty-two patients were excluded. Of the remaining 61 patients, 28 patients presented with DSP, 20 patients with accidental overdose, and 13 patients with an ADR; no patients presented with recreational use. It was noted that ADRs were largely idiosyncratic reactions and not always related to dose adjustments. In the context of therapeutic misadventure and DSP, we noted that a lower mean dose achieved a higher poison severity score (PSS) in clozapine-naive patients when compared to those patients on regular clozapine.

CONCLUSIONS

The presentation of clozapine-related toxicity differs depending on the modality of ingestion, whether DSP, accidental, or as a result of ADR. Patients naive to clozapine therapy tend to experience higher PSS with lower doses ingested either in a deliberate self-poisoning or accidental ingestion context. This is likely due to tolerance to the sedative properties of clozapine. No patients manifested clinical toxicity greater than 8 hours after ingestion, with an observation period of 6 hours accurately identifying toxicity in most patients.

Two-year cohort-up study of clozapine prescription in Chinese patients with schizophrenia treated in rural primary care

Few studies have examined the clozapine in cohort studies of Chinese patients with schizophrenia in rural primary care. The objective of this two-year cohort study was to describe the usage of clozapine and investigate and identify the demographic, clinical correlations and risk variables which affect the use of clozapine in patients with schizophrenia. A random cluster sampling technique was used, and participants were collected from China National Psychiatric Management System (CNPMS). The variables for clozapine use in individuals with schizophrenia who had undergone a two-year follow-up were determined using the generalized estimating equation (GEE). In this study, 742 patients with schizophrenia were invited, and 491 completed the two-year follow-up study. Being married, more years of education, more waist circumference, using mood stabilizer, using anticholinergic, higher ITAQ (Insight and Treatment Attitude Questionnaire) scores were more significantly related to the use of clozapine. Older age of onset, using second-generation antipsychotics (SGAs) except clozapine predicted a lower prevalence of using clozapine. The usage of clozapine was very common in patients with schizophrenia treated by primary care physicians, and was influenced by a variety of factors, including price of drugs, clinical factors, health regulations, and the characteristics of treatment environment. Further examination of the rationale and appropriateness of clozapine in primary care in China is necessary.