Study of the Effect of Dosing on Clozapine Levels
Information source: University of British Columbia
ClinicalTrials.gov processed this data on August 20, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Psychotic Disorders; Schizophrenia
Intervention: Clozapine (Drug)
Phase: Phase 4
Status: Not yet recruiting
Sponsored by: University of British Columbia Official(s) and/or principal investigator(s): Ric M. Procyshyn, Ph.D, Principal Investigator, Affiliation: University of British Columbia Alasdair Barr, Ph.D, Study Director, Affiliation: University of British Columbia William Honer, MD, Study Director, Affiliation: University of British Columbia Randall White, MD, Study Director, Affiliation: University of British Columbia
Overall contact: Heidi Boyda, Ph.D, Phone: 604-822-7500, Email: hnboyda@gmail.com
Summary
The objectives of this 15-day study are:
1. To compare steady-state trough plasma concentrations of clozapine and its metabolite
norclozapine when given once daily and twice daily (at the same total daily dose)
2. To determine if frequency of clozapine administration has an effect on:
1. Symptoms of schizophrenia
2. Adverse effects of clozapine
3. Fasting blood glucose, lipids, creatinine, and urea
4. Weight and waist circumference
Clinical Details
Official title: A Pilot Study to Determine How Frequency of Administration Modifies Steady-State Plasma Concentrations of Orally Administered Clozapine
Study design: Endpoint Classification: Pharmacokinetics Study, Intervention Model: Single Group Assignment, Masking: Open Label
Primary outcome: Change from baseline in steady-state trough plasma concentrations of clozapine and norclozapine at Days 7 and 14.
Secondary outcome: Change from baseline in symptoms at Day 14.Change from baseline in side effect burden at Day 14 Changes from baseline in laboratory measures at Day 14. Change from baseline in weight and waist circumference at Day 14.
Detailed description:
It is important that clinicians do everything possible to optimize the use of clozapine in
individuals with treatment-resistant schizophrenia. To our knowledge, there are no published
studies evaluating whether twice daily administration of clozapine is better than once daily
administration in terms of effectiveness and tolerability. Although this may seem trivial at
first, when we consider that clozapine has a relatively short half-life and dissociates
quickly from the dopamine D2 receptor, it justifies further consideration. It takes on even
more significance knowing that the established threshold clozapine plasma concentration for
therapeutic response (i. e., 350-420 ng/ml) was determined using steady-state trough plasma
samples (i. e., approximately 12 hours after the evening dose) in patients administered
clozapine twice rather than once daily.
Eligibility
Minimum age: 19 Years.
Maximum age: 65 Years.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Participants must be between the ages of 19 - 65
- Participants must be fluent in English
- Participants must have a psychiatric diagnosis and are currently treated with
clozapine once daily in the evening
- Participants must be on a stable dose of clozapine for at least one week to ensure
steady-state has been achieved
Exclusion Criteria:
- Participants who are hypersensitive to clozapine
- Participants who are pregnant or lactating
- Participants who are of childbearing age and not using reliable contraception
- Participants who have postsurgical complications of the gastrointestinal tract that
might impair absorption
- Participants who have any clinically relevant abnormalities of laboratory parameters
- Participants who have had a potent CYP1A2 metabolic inducer (e. g., carbamazepine;
rifampin) or inhibitor (e. g., amiodarone; cimetidine; efavirenz; fluoroquinolone
antibiotics; ticlopidine) added to and/or removed from their medication regimen in
the past two weeks
Locations and Contacts
Heidi Boyda, Ph.D, Phone: 604-822-7500, Email: hnboyda@gmail.com
UBC Hospital - Detwiller Pavilion, Vancouver, British Columbia V6T 2A1, Canada; Not yet recruiting Ric M. Procyshyn, Ph.D, Principal Investigator Alasdair Barr, Ph.D, Sub-Investigator William Honer, MD, Sub-Investigator Randall White, MD, Sub-Investigator
Additional Information
Starting date: January 2015
Last updated: November 4, 2014
|