Switching From Twice-Daily to Once-Daily Clozapine Dosing in Schizophrenia
Trial statusRecruiting
Trial phasePhase 4
Trial typeInterventional
Biological sexAll
Age18+
SponsorCentre for Addiction and Mental Health
About this trial
Plasma half-life has routinely been used to establish the dosing schedule of antipsychotics; for example, it is recommended that agents with a short plasma half-life be administered multiple times per day. However, to date, several randomized controlled trials (RCTs) have shown no differences in clinical outcomes between once- and twice-daily dosing of various antipsychotics, suggesting that once-daily dosing of antipsychotics is a viable option regardless of plasma half-life. This would apply to clozapine as well; however, there have been no studies comparing once-daily vs. twice-daily dosing regimens of clozapine in terms of efficacy and tolerability. To address this gap in the literature, the investigators shall conduct a pilot, double-blind, RCT to examine efficacy and tolerability following a switch to once-daily dosing regimen of clozapine in patients with schizophrenia receiving clozapine twice a day.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Diagnosed with schizophrenia or schizoaffective disorder based on DSM-IV criteria
Outpatient status
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
Disqualifiers
Having significant medical or neurological illnesses
Pregnant or lactating
Trial design
Design model
Parallel
Treatments tested in this trial
Clozapine
DrugSwitching from twice-daily to once-daily clozapine dosing regimen
Treatment groups
30 Participants
are divided into 2 treatment groupsGroup A: Switch groupExperimental treatment 1 intervention
Group B: Maintenance groupNo intervention 0 interventions
Trial outcomes
Primary outcomes
1
Brief Psychiatric Rating 18 item Scale (BPRS 18 item scale)
Change in BPRS total scores from baseline to 12 weeks Total scores range from 18-126, higher scores represent worse clinical outcomes: \<31 = Illness not significant \>=31 = Mildly ill \>41 = Moderately ill \>53 = Markedly ill.
Time frame
0 and 12 weeksSecondary outcomes
1
Glasgow Antipsychotic Side-effect Scale for Clozapine (GASS-C)
Detect side effects related to Clozapine from baseline to 12 weeks Higher Scores indicating worse side-effects: 0-16 (absent/mild side-effects) 17-32 (moderate side-effects) 33-48 (severe side-effects)
Time frame
0 and 12 weeks2
Brief Evaluation of Psychosis Symptom Domains (BE-PSD)
Assess the overall severity of five symptom domains of BE-PSD with a total score in each domain scoring from absent to very severe (i.e. 0-6 with higher scores with worse outcomes)
Time frame
0 and 12 weeks3
Personal and Social Performance scale (PSP)
Change in patients social functioning scores from baseline to 12 weeks The PSP is a 100-point single item rating scale from 1-100, subdivided into 10 equal intervals with higher scores indicating better outcomes. The ratings are based on patient's functioning in four main areas: 1) socially useful activities, 2) personal and social relationships, 3) self-care; and 4) disturbing and aggressive behaviours.
Time frame
0 and 12 weeks4
Clinical Global Impression - Severity of Illness (CGI-S)
Assess severity of Illness in Schizophrenia CGI scores from baseline to 12 weeks Scores ranging from normal to the most ill (i.e., scores ranging from 1-7 with higher scores with illness worsening)
Time frame
0 and 12 weeksSponsors and contacts
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Source ClinicalTrials.gov