ArticleSchizophrenia bulletin2007
Clozapine underutilization and discontinuation in African Americans due to leucopenia.
Article in Schizophrenia bulletin, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT02692755 (Phase II Safety Study of Palbociclib in Combination With Letrozole or Fulvestrant in African American Women With Hormone Receptor Positive HER2 Negative Advanced Breast Cancer), which is not on this map. Cited by 34 papers, 2 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Phase II Safety Study of Palbociclib in Combination With Letrozole or Fulvestrant in African American Women With Hormone Receptor Positive HER2 Negative Advanced Breast Cancer
Who cites it
34 citing papers in PubMed, 2 syntheses or guidelines pooled it, 101 citations in OpenAlex.
- Exploring Biologic Predictors Response Disparities to Atypical Antipsychotics among Blacks: A Quasi-Systematic Review.Ethnicity & disease · 2020Pooled it
- When can patients with potentially life-threatening adverse effects be rechallenged with clozapine? A systematic review of the published literature.Schizophrenia research · 2012Pooled it
- Clozapine and neutrophil response in patients of African descent: A six-month, multinational, prospective, open-label clinical trial.Schizophrenia research · 2024Trial
- Trial
- Proportion and Reasons for Clozapine Discontinuation: A Systematic Review and Meta-Analysis.Schizophrenia bulletin open · 2026Review
- Characterization of the phenotypic consequences of the Duffy-null genotype.Blood advances · 2025Article
- Differences in schizophrenia treatments by race and ethnicity-analysis of electronic health records.Schizophrenia (Heidelberg, Germany) · 2024Article
- Medical, Psychiatric, and Sociodemographic Predictors of Clozapine Initiation at an Academic Medical Center.Psychiatric research and clinical practice · 2024Article
- Social Determinants of Health in People Living with Psychiatric Disorders: The Role of Pharmacists.Health equity · 2023Review
- Benign ethnic neutropenia: an analysis of prevalence, timing and identification accuracy in two large inner-city NHS hospitals.BMC psychiatry · 2021Observational
- There Is Life After the UK Clozapine Central Non-Rechallenge Database.Schizophrenia bulletin · 2021Observational
- Cluster Analysis of Clozapine Consumer Perspectives and Comparison to Consumers on Other Antipsychotics.Schizophrenia bulletin open · 2021Article
- Clozapine Metabolism is Associated With Absolute Neutrophil Count in Individuals With Treatment-Resistant Schizophrenia.Frontiers in pharmacology · 2021Article
- The Duffy-null genotype and risk of infection.Human molecular genetics · 2020Article
- A Rational Use of Clozapine Based on Adverse Drug Reactions, Pharmacokinetics, and Clinical Pharmacopsychology.Psychotherapy and psychosomatics · 2020Review
- The side effect profile of Clozapine in real world data of three large mental health hospitals.PloS one · 2020Article
- Benign ethnic neutropenia.Blood reviews · 2019Review
- A genome-wide association study in individuals of African ancestry reveals the importance of the Duffy-null genotype in the assessment of clozapine-related neutropenia.Molecular psychiatry · 2019Article
- PALINA: A phase II safety study of palbociclib in combination with letrozole or fulvestrant in African American women with hormone receptor positive HER2 negative advanced breast cancer.Contemporary clinical trials communications · 2018Article
- Clozapine in Reducing Aggression and Violence in Forensic Populations.The Psychiatric quarterly · 2018Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
Abstract
Clozapine use has been notably lower in African American patients than in Caucasians. It has been suggested that lower normal ranges for white blood cell (WBC) counts in African Americans, known as benign ethnic neutropenia, may account partially for the disparity. We examined the rates of leucopenia and agranulocytosis as reasons for discontinuation of clozapine in a sample of 1875 patients with schizophrenia treated in the State of Maryland. Between 1989 and 1999, 5.3% (31/588) of African Americans and 2.4% (31/1287) of Caucasians discontinued clozapine treatment due to leucopenia (chi square = 10.35, df = 1, P = 0.001). No African American patients developed agranulocytosis while 8 Caucasian patients (0.62%) developed this blood dyscrasia. Discontinuations due to leucopenia occurred throughout treatment. Discontinuations due to agranulocytosis occurred primarily in the first 18 weeks (7/8; 87.5% patients with agranulocytosis). It is likely that African Americans had clozapine discontinued unnecessarily due to benign ethnic neutropenia. We concur with recent recommendations to acknowledge differences in WBC values in African Americans and to modify prescribing guidelines or formally acknowledge benign ethnic leucopenia like in other countries in order to facilitate greater use of clozapine in these patients.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.