Treatment strategies for clozapine-induced hypotension: a systematic review

Overcoming clozapine's adverse events: a narrative review of systematic reviews and meta-analyses

INTRODUCTION

Clozapine is the gold standard treatment for treatment-resistant schizophrenia, however adverse events remain a clinical challenge.

AREAS COVERED

This review presents a narrative synthesis of systematic reviews and meta-analyses that have reported the onset, incidence, prevalence, and management of clozapine's adverse events. We conducted a systematic literature search using PubMed, Embase, PsycINFO, OvidMEDLINE, CINAHL, and the Cochrane Database of Systematic Reviews from inception to April 2024.

EXPERT OPINION

Effective management of clozapine's adverse events necessitates multi-faceted, individualized, and shared-decision strategies. Despite a lack of high-quality systematic evidence, expert inter-disciplinary solutions are provided to help address a critical need for clinical guidance. This 35-year update offers an evidence-based framework to assist clinicians, patients, and caregivers navigate the adverse events associated with clozapine therapy.

Evaluation of major adverse events of clozapine based on accordance to an international titration guideline

Introduction

Clozapine is the only antipsychotic approved for treatment-resistant schizophrenia, but without appropriate monitoring, it can be associated with potentially fatal outcomes. An International Adult Clozapine Titration Guideline categorizes patients into normal or slow metabolizers. Categorization provides clozapine titration schedules and recommends regular c-reactive protein (CRP) and clozapine concentration monitoring to reduce the risk of adverse drug reactions (ADRs). The impact of the guideline on clozapine ADRs has not been evaluated.

Methods

A retrospective chart review assessed clozapine titrations, laboratory monitoring, ADRs, and discontinuations for clozapine-naive adult inpatients at a single center from January 1, 2013, to June 1, 2022. Each patient's cumulative weekly clozapine dosage was compared with their guideline recommended dosage to create a percent accordance. Linear logistic regression evaluated the relationship between titration speed and the presence of an ADR, while descriptive statistics analyzed laboratory monitoring.

Results

Forty-three patients were included, with the majority being White males with schizophrenia. An inverse relationship existed between the last inpatient week clozapine dose percent accordance and the probability of an ADR. Nonobese patients were less likely than obese patients to experience an ADR (odds ratio = 0.17; 95% CI, 0.03-0.99). CRP and clozapine concentration monitoring was suboptimal.

Discussion

Based on our small retrospective review of primarily White males, more aggressive clozapine titrations did not increase ADRs. Future studies with more diverse samples are needed and should focus on specific ADRs, which may have increased occurrence with rapid titrations. Obese patients were at higher risk of ADRs, correlating with the guideline-recommended slower titrations for these patients.

Inpatient antipsychotic medication switching and rehospitalization risk among patients with schizophrenia-spectrum disorders

OBJECTIVE

To describe patterns of antipsychotic switching among patients hospitalized for schizophrenia and to correlate antipsychotic switching with hospital readmission risk.

METHODS

We identified 3295 patients with index hospitalizations for schizophrenia or schizoaffective disorder from New York State Medicaid claims 2017-2018 who had filled at least one prescription for an antipsychotic in both the 44 days (one month +14 day grace period) prior to and after their admission. We identified patients who had kept or switched any of their antipsychotic medication between the pre- and post-periods surrounding their index hospitalization. We compared the kept and switched any groups, adjusting for patient characteristics.

RESULTS

Of patients who had filled antipsychotic prescriptions in both the 44 days prior to and after their hospitalization, 1599 (48.6 %) had switched at least one antipsychotic and 1215 (36.8 %) had switched their primary antipsychotic. Switching any antipsychotic was associated with increased hazards of readmission, HR = 1.21, 95%CI 1.09-1.35, which was slightly concentrated during the first 90 days after hospital discharge.

CONCLUSIONS

Switching antipsychotic medications during hospitalization occurs commonly and is associated with higher rehospitalization risk following hospital discharge.

Benefits and Risks of Medications Used in the Management of Hypotension: A Review

This comprehensive literature review addresses the scarcity and limited study of hypotension treatments compared to abundant antihypertensive drugs. Hypotension, categorized as absolute, relative, or orthostatic, has diverse causes. This review explores various treatments, including drugs affecting the sympathetic nervous system, such as midodrine, dihydroergotamine, and ergotamine, which have shown efficacy in managing hypotension. Dopamine agonists/antagonists and other drugs such as ephedrine, norepinephrine, and fludrocortisone are also discussed, each with distinct mechanisms and applications. Additionally, adjunctive agents such as non-steroidal anti-inflammatory agents, caffeine, and monoamine oxidase inhibitors are reviewed for their effects on blood pressure. This review underscores the importance of understanding the efficacy and safety profiles of hypotension treatments to guide healthcare professionals in optimal drug selection and management, emphasizing the need for further research and comparative studies for evidence-based guidelines.

Developing prediction models for symptom severity around the time of discharge from a tertiary-care program for treatment-resistant psychosis

Antipsychotics are the only therapeutic class indicated in the symptomatic management of psychotic disorders. However, individuals diagnosed with schizophrenia or schizoaffective disorder may not always benefit from these first-line agents. This refractoriness to conventional treatment can be difficult to address in most clinical settings. Therefore, a referral to a tertiary-care program that is better able to deliver specialized care in excess of the needs of most individuals may be necessary. The average outcome following a period of treatment at these programs tends to be one of improvement. Nonetheless, accurate prognostication of individual-level responses may be useful in identifying those who are unlikely to improve despite receiving specialized care. Thus, the main objective of this study was to predict symptom severity around the time of discharge from the Refractory Psychosis Program in British Columbia, Canada using only clinicodemographic information and prescription drug data available at the time of admission. To this end, a different boosted beta regression model was trained to predict the total score on each of the five factors of the Positive and Negative Syndrome Scale (PANSS) using a data set composed of 320 hospital admissions. Internal validation of these prediction models was then accomplished by nested cross-validation. Insofar as it is possible to make comparisons of model performance across different outcomes, the correlation between predictions and observations tended to be higher for the negative and disorganized factors than the positive, excited, and depressed factors on internal validation. Past scores had the greatest effect on the prediction of future scores across all 5 factors. The results of this study serve as a proof of concept for the prediction of symptom severity using this specific approach.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

Clozapine is the approved option in treatment-resistant schizophrenia and requires careful management

Clozapine is the only agent approved for treatment-resistant schizophrenia, but is underprescribed. Its adverse drug event (ADE) profile and patient monitoring requirements can discourage its use, but the benefits of clozapine generally outweigh its risks, as most ADEs are manageable. Careful patient assessment, gradual titration, minimum effective dosages, therapeutic drug monitoring and checks of neutrophils, cardiac enzymes and ADE symptoms are recommended. Neutropenia is common but does not necessarily warrant permanent clozapine cessation.