Trial reportJournal of clinical psychopharmacology2018
The Effect of Body Weight Changes on Total Plasma Clozapine Concentrations Determined by Applying a Statistical Model to the Data From a Double-Blind Trial.
Trial report in Journal of clinical psychopharmacology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
25 citing papers in PubMed, 1 synthesis or guideline pooled it, 57 citations in OpenAlex.
- Population Pharmacokinetics of Clozapine: A Systematic Review.BioMed research international · 2020Pooled it
- Review
- Risk factors for sudden cardiac death or sudden unexplained death in patients treated with clozapine: systematic review.BJPsych open · 2026Review
- Review
- Clozapine-Induced Myocarditis in Huntington's Disease: Case Report.Turk psikiyatri dergisi = Turkish journal of psychiatry · 2026Article
- Exploratory analysis of non-linear clozapine dose-concentration relationship in real-life hospital database.Frontiers in pharmacology · 2025Article
- Effect of Organic Anion Transporting Polypeptide 1B1 on Plasma Concentration Dynamics of Clozapine in Patients with Treatment-Resistant Schizophrenia.International journal of molecular sciences · 2024Article
- Analysis of clinical studies on clozapine from 2012-2022.Naunyn-Schmiedeberg's archives of pharmacology · 2024Review
- Review
- Advocating for the inclusion of therapeutic drug monitoring in the national essential diagnostic list: Perspectives from psychiatrists.Indian journal of psychiatry · 2024Article
- The effects of clinical and pharmacological factors on the ratio of clozapine to norclozapine in psychiatric patients.Frontiers in pharmacology · 2024Article
- Clinical and pharmacological factors influencing serum clozapine and norclozapine levels.Frontiers in pharmacology · 2024Article
- Body mass index as a predictor of the outcomes of acute clozapine toxicity: a cross-sectional study.Toxicology research · 2023Article
- Reflections on the Lack of Consideration of Ethnic Ancestry to Stratify Clozapine Dosing.Psychiatry investigation · 2023Article
- Pharmacometric modeling of drug adverse effects: an application of mixture models in schizophrenia spectrum disorder patients treated with clozapine.Journal of pharmacokinetics and pharmacodynamics · 2023Article
- The potential effect of metformin on cognitive and other symptom dimensions in patients with schizophrenia and antipsychotic-induced weight gain: a systematic review, meta-analysis, and meta-regression.Frontiers in psychiatry · 2023Review
- Real-World Analysis of Antipsychotic Drugs' Effect on Weight Gain: An EHR Application.AMIA ... Annual Symposium proceedings. AMIA Symposium · 2023Article
- Current Status of Therapeutic Drug Monitoring in Mental Health Treatment: A Review.Pharmaceutics · 2022Review
- The Impact of Smoking, Sex, Infection, and Comedication Administration on Oral Olanzapine: A Population Pharmacokinetic Model in Chinese Psychiatric Patients.European journal of drug metabolism and pharmacokinetics · 2021Article
- Self-Report for Measuring and Predicting Medication Adherence: Experts' Experience in Predicting Adherence in Stable Psychiatric Outpatients and in Pharmacokinetics.Patient preference and adherence · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
PURPOSE/
backgroundSome therapeutic drug monitoring studies suggest that increased weight is associated with small increases in clozapine concentrations. The goal of this study was to reanalyze a US double-blind study using a sophisticated statistical model to test whether weight gains from baseline or increases in percentage of body fat from baseline, computed from a published equation, are associated with increased total plasma clozapine concentrations after controlling for the effects of smoking and sex. METHODS/PROCEDURES: Using data from a multidosage randomized double-blind US clozapine trial previously published, a random intercept linear model of steady-state total plasma clozapine concentrations was fitted to 424 concentrations from 47 patients. FINDINGS/
resultsAfter adjusting for sex and smoking, (1) a 1-kg gain in body weight during clozapine treatment was significantly associated with a 1.4% increase in total plasma clozapine concentrations (95% confidence interval = 0.55 to 2.3) and (2) a 1-point increase in percentage of body fat during clozapine treatment was significantly associated with a 5.4% increase in total clozapine concentration (2.5 to 8.3) in females and 1.4% (-1.1 to 4.0) in males. IMPLICATIONS/
conclusionsAs hypothesized, weight increases during clozapine treatment, which probably reflect increases in fat tissue, were associated with increases in total plasma concentrations. Pending further replication in other samples, it seems likely that clozapine may deposit in body fat and that this may decrease clozapine clearance. This change may be small in most patients but may be clinically relevant in females with major gains in body fat.
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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.