Evidence map›Paper›PMID 34046160›Full record

ArticleTherapeutic advances in psychopharmacology2021

Comprehensive assessment of exposure to clozapine in association with side effects among patients with treatment-resistant schizophrenia: a population pharmacokinetic study.

Nobuyuki Nomura, Kohei Kitagawa, Ryuhei So, Fuminari Misawa, Masafumi Kodama, Hiroyoshi Takeuchi, Robert Bies, Thomas Straubinger, Christopher Banker, Yuya Mizuno and 2 more

Open access · goldAbstract read
In one paragraph

Article in Therapeutic advances in psychopharmacology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
0.6field-weighted citation impact, top 35% of its field
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 5 citations in OpenAlex.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors at 5 institutions in 3 countries.

Nobuyuki NomuraDepartment of Neuropsychiatry, Yamanashi Prefectural Kita Hospital, Yamanashi, Japan.
Kohei KitagawaDepartment of Neuropsychiatry, Okayama Psychiatric Medical Center, 3-16, Shikatahonmachi, Kita-ku, Okayama-shi, Okayama, 700-0915, Japan.
Ryuhei SoDepartment of Neuropsychiatry, Okayama Psychiatric Medical Center, 3-16, Shikatahonmachi, Kita-ku, Okayama-shi, Okayama, 700-0915, Japan.
Fuminari MisawaDepartment of Neuropsychiatry, Yamanashi Prefectural Kita Hospital, Yamanashi, Japan.
Masafumi KodamaDepartment of Neuropsychiatry, Okayama Psychiatric Medical Center, Okayama, Japan.
Hiroyoshi TakeuchiDepartment of Neuropsychiatry, Yamanashi Prefectural Kita Hospital, Yamanashi, Japan.
Robert BiesDepartment of Pharmaceutical Sciences, University at Buffalo, New York, USA.
Thomas StraubingerDepartment of Pharmaceutical Sciences, University at Buffalo, New York, USA.
Christopher BankerDepartment of Pharmaceutical Sciences, University at Buffalo, New York, USA.
Yuya MizunoDepartment of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
Masaru MimuraDepartment of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
Hiroyuki UchidaDepartment of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.ORCID https://orcid.org/0000-0002-0628-7036
Keio University · JPOkayama Psychiatric Medical Center · JPUniversity at Buffalo, State University of New York · USKeio University Hospital · JPKing's College London · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThere have been scarce data on the distribution of clozapine concentrations in comparison with the recommended range (350-600 ng/ml) or their relationship with side effects among patients with treatment-resistant schizophrenia. Furthermore, no studies have assessed the association between side effects and overall exposure to the drug by calculating the 24-h area-under-curve (AUC).

methodsIn- and outpatients with schizophrenia or schizoaffective disorder (ICD-10) who were receiving a stable dose of clozapine for ⩾2 weeks were included. Side effects were assessed using the Glasgow antipsychotic side-effects scale for clozapine (GASS-C). Using two collected plasma samples, plasma clozapine and norclozapine concentrations at peak and trough and their 24-h AUC were estimated using population pharmacokinetic models.

resultsA total of 108 patients completed the study (mean ± SD age, 43.0 ± 10.1 years; clozapine dose, 357.5 ± 136.9 mg/day); 33 patients (30.6%) showed estimated trough concentrations of clozapine within the recommended range (350-600 ng/ml) whereas the concentrations were higher and lower than this range among 37 (43.5%) and 28 (25.9%) patients (%), respectively. There were no significant correlations between estimated peak or trough concentrations or 24-h AUC of both clozapine or norclozapine, and GASS-C total or individual scores. No significant differences were found between GASS-C total or individual item scores between the patients with estimated trough concentrations of clozapine of >600 ng/ml and the other subjects.

conclusionThe results suggest that clozapine or norclozapine concentrations are not linked directly to the extent of side effects experienced in clozapine-treated patients with treatment-resistant schizophrenia while the cross-sectional study design limits the interpretation of any causal relationships. These findings indicate that side effects associated with clozapine may occur at any dose or concentration.

Indexed as

clozapinepharmacokineticsschizophrenia

Identifiers

PMID34046160
PMCPMC8138292
OpenAlexW3160308778

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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.