A Phase 1 interventional study of clozapine and pantoprazole in Healthy Volunteers - Male and Female, sponsored by Universiti Sains Malaysia. Completed at 1 site in Malaysia. Open to participants aged 18 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-04.
Sponsored by Universiti Sains Malaysia · Phase 1, Interventional, and Other
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.
Universiti Sains Malaysia is the lead sponsor of 171 studies on the registry; 48 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Single dose of 12.5 mg clozapine
Drug: clozapine
Single dose of 12.5 mg clozapine after five daily doses of pantoprazole tablets 40 mg to be started four days prior to the clozapine administration
Drug: clozapine · Drug: pantoprazole
Single dose of 12.5 mg clozapine (half 25 mg tablet)
Five daily doses of pantoprazole tablets 40 mg to be started four days prior to the clozapine administration
Peak Plasma Concentration (Cmax)
Maximum plasma concentration of clozapine following a single oral dose
Time frame: From pre-dose to 8 hours after a single oral dose of clozapine
Area Under the Plasma Concentration-Time Curve (AUC)
AUC of clozapine plasma concentration from time zero to the last measurable concentration following a single oral dose
Time frame: From pre-dose to 8 hours after dosing
Area Under the Concentration-Time Curve Extrapolated to Infinity (AUCinf)
Area under the plasma concentration-time curve from time zero extrapolated to infinity
Time frame: From pre-dose to last measurable concentration
Time to Peak Concentration (Tmax)
Time to reach maximum observed plasma concentration of clozapine
Time frame: From pre-dose to 8 hours after dosing
Plan to share: Yes — The datasets generated during and analysed during the current study are available from the corresponding author on reasonable request.
This study is completed, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
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Universiti Sains Malaysia