Evidence map›Paper›PMID 40694104›Full record

ArticleEuropean journal of clinical pharmacology2025

Pharmacogenetics and pharmacometabolomics predictors of clozapine and norclozapine pharmacokinetic exposure in healthy volunteers.

Orwa Albitar, Mohd Rahimi Muda, Siti Maisharah Sheikh Ghadzi, Dzul Azri Mohamed Noor, Baharudin Ibrahim, Chin-Hoe Teh, Mohammed Ahmed Akkaif, Fatimatuzzahra' Abd Aziz

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Article in European journal of clinical pharmacology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07262736 (Pharmacokinetics of Clozapine and Norclozapine and the Effect of Pantoprazole), which is not on this map. Not yet cited in PubMed.

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1 · What the graph read from 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.

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.

NCT07262736 phase1completednot on this map

Pharmacokinetics of Clozapine and Norclozapine and the Effect of Pantoprazole

TypeinterventionalSponsorUniversiti Sains MalaysiaRan2021 to 2022Enrolled33ConditionsHealthy Volunteers - Male and FemaleArmsclozapine, pantoprazole
3 · Its place in the literature

Who cites it

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4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

8 authors.

Orwa AlbitarSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia. orwa.bit@gmail.com.
Mohd Rahimi MudaSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
Siti Maisharah Sheikh GhadziSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
Dzul Azri Mohamed NoorSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
Baharudin IbrahimFaculty of Pharmacy, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Chin-Hoe TehBruker Sdn Bhd, Penang, Malaysia.
Mohammed Ahmed AkkaifDepartment of Cardiology, QingPu Branch of Zhongshan Hospital Affiliated to Fudan University, Shanghai, 201700, China. akkaif@fudan.edu.cn.
Fatimatuzzahra' Abd AzizSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia. faa@usm.my.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeClozapine is the only effective medication for unresponsive schizophrenia. However, it has a complicated dose-concentration relationship. The present study aimed to investigate the role of some genetic polymorphisms and metabolic profiles in addressing the variability in clozapine and norclozapine concentrations.

methodsA single dose of 12.5 mg clozapine was administered to 33 healthy volunteers, from whom 270 samples were collected at 30 min, 1, 2, 3, 5, and 8 h. The concentrations of clozapine and norclozapine were determined using HPLC-UV. CYP1A2 -163 C>A, ABCB1 3435 C>T, and ABCB1 2677 G>T genetic polymorphisms were investigated using allele-specific polymerase chain reaction and restriction fragment length polymorphism, and the metabolic profiles were identified using proton nuclear magnetic resonance (

resultsClozapine concentrations and area under the curve (AUC) were higher, and the clearance was 38.3% (95% confidence intervals (95% CI), 4.5-72.2%) lower in the CYP1A2 -163 AA genotype, while clozapine initial concentrations were lower in the ABCB1 2677 GG genotype. In a multiple regression analysis, glucose (p-value, 0.009) was significantly associated with the norclozapine to clozapine AUC (N:C) ratio.

conclusionsVariabilities in clozapine pharmacokinetics were accounted for using genetic polymorphisms and metabolic profiles. Clozapine concentrations in CYP1A2 -163 C>A polymorphism should be cautiously interpreted considering the smoking status. Altered glucose levels, besides being an adverse effect of clozapine, may also be indirectly associated with variability in CYP1A2 activity as indicated by the N:C ratio to be confirmed in larger and controlled trials.

Indexed as

Antipsychotic AgentsClozapineCytochrome P-450 CYP1A2AdultATP Binding Cassette Transporter, Subfamily BFemaleGenotypeHealthy VolunteersHumansMaleMetabolomicsMiddle AgedPharmacogeneticsPolymorphism, Single NucleotideYoung AdultABCB1 protein, humanAntipsychotic AgentsATP Binding Cassette Transporter, Subfamily BClozapineCYP1A2 protein, humanCytochrome P-450 CYP1A2norclozapineClozapineNorclozapinePharmacogeneticsPharmacokineticsPharmacometabolomics

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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 Socratic graph.