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Once-Daily vs Twice-Daily Clozapine for Schizophrenia

Phase 4

Recruiting

Led By Gary Remington, MD, PhD

Research Sponsored by Centre for Addiction and Mental Health

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Ages 18 years or older

Has received clozapine twice a day, one of which is in the evening/bedtime, at the same dose and dosing regimen for at least 3 months

Timeline

Screening 3 weeks

Treatment Varies

Follow Up 0 and 12 weeks

Awards & highlights

Study Summary

This trial will compare the effects of taking clozapine once a day versus taking it twice a day.

Who is the study for?

This trial is for adults over 18 with schizophrenia or schizoaffective disorder, currently taking clozapine twice daily. They must be outpatients, fluent in English, and able to consent. It's not for those with serious medical conditions or women who are pregnant or breastfeeding.Check my eligibility

What is being tested?

The study tests if taking clozapine once a day is as effective and tolerable as the standard twice-daily dose for schizophrenia treatment. Participants will be randomly assigned to one of the dosing schedules in a controlled environment.See study design

What are the potential side effects?

Clozapine can cause side effects like drowsiness, dizziness, rapid heartbeat, constipation, excessive salivation, and in rare cases may affect white blood cell count leading to infection risk.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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I am 18 years old or older.

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I have been taking clozapine twice daily, including bedtime, at the same dose for 3 months.

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I have been diagnosed with schizophrenia or schizoaffective disorder.

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I am not currently admitted to a hospital.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ 0 and 12 weeks

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~0 and 12 weeks

This trial's timeline: 3 weeks for screening, Varies for treatment, and 0 and 12 weeks for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.

Primary outcome measures

Brief Psychiatric Rating 18 item Scale (BPRS 18 item scale)

Secondary outcome measures

Brief Evaluation of Psychosis Symptom Domains (BE-PSD)

Brief Neurocognitive Assessment (BNA)

Fetal Distress

+4 more

Side effects data

From 2008 Phase 4 trial • 25 Patients • NCT00001656

31%

Increased appetite

31%

Hypersalivation

17%

tachycardia >100 beats/min (supine)

15%

Somnolence

15%

Constipation

Hypertension

Difficulty concentrating

Insomnia

Enuresis

Abnormal white blood count

100%

80%

60%

40%

20%

Study treatment Arm

Olanzapine Group

Clozapine Group

Trial Design

2Treatment groups

Experimental Treatment

Active Control

Group I: Switch groupExperimental Treatment1 Intervention

Participants will receive clozapine once daily at evening or bedtime throughout the study period. If a participant takes ≥200 mg of clozapine at a time other than evening/bedtime, half of this dose will be switched to an evening/bedtime regimen on day 0 (baseline), then another half dose will be switched on day 7 (week 1). Participants will receive placebo in place of the clozapine dose that was switched to evening/bedtime.

Group II: Maintenance groupActive Control1 Intervention

Participants will continue to take clozapine twice daily throughout the study period.

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

Clozapine

2000

Completed Phase 4

~1540

0 / 4Eligibility criteria met