Pharmacokinetics of Clozapine and Norclozapine and the Effect of Pantoprazole
Summary
Clozapine is an effective treatment for patients with schizophrenia who do not respond to other therapies, but its blood concentration varies widely between individuals due to genetic and physiological differences. Proton pump inhibitors such as pantoprazole are often prescribed in this population to prevent stomach discomfort, yet their impact on clozapine exposure has not been fully characterized. This clinical study will investigate the pharmacokinetics of clozapine and its main metabolite norclozapine, the influence of individual characteristics on drug exposure, and the effect of pantoprazole coadministration. Healthy adult volunteers will participate in a randomized open label cross over design, receiving a single dose of clozapine alone and again after pantoprazole treatment. Outcomes include clozapine and norclozapine plasma concentration time profiles, pharmacokinetic parameters, and safety assessments.
Timeline
- Start
- 2021-02-06
- Primary completion
- 2022-02-28
- Completion
- 2022-02-28
Publications
- Results Albitar O, Muda MR, Ghadzi SMS, Noor DAM, Ibrahim B, Teh CH, Akkaif MA, Aziz FA. Pharmacogenetics and pharmacometabolomics predictors of clozapine and norclozapine pharmacokinetic exposure in healthy volunteers. Eur J Clin Pharmacol. 2025 Oct;81(10):1429-1438. doi: 10.1007/s00228-025-03884-w. Epub 2025 Jul 22.
- Results Albitar O, Harun SN, Sheikh Ghadzi SM. Semi-physiological Pharmacokinetic Model of Clozapine and Norclozapine in Healthy, Non-smoking Volunteers: The Impact of Race and Genetics. CNS Drugs. 2024 Jul;38(7):571-581. doi: 10.1007/s40263-024-01092-1. Epub 2024 Jun 5.
Drugs
| Evaluation | Drug | Modality | Dose | Route |
|---|---|---|---|---|
| Comparator | Clozapine | Other / unclassified | 12.5 mg | — |
| Comparator | Pantoprazole | Other / unclassified | 40 mg | — |
Indications
No indication recorded.