Clinical trial NCT02639702: Switching From Twice-Daily to Once-Daily Clozapine Dosing in Schizophrenia
Official title: Switching From Twice-Daily to Once-Daily Clozapine Dosing in Schizophrenia: A Pilot, Double-Blind, Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE4
Conditions: Schizophrenia
Schizoaffective Disorder
Keywords: Clozapine
Dosing
Once daily
Regimen
Schizophrenia
Lead sponsor: Centre for Addiction and Mental Health
Sponsor class: OTHER
First posted: 2015-12-24
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: 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.

Detailed description: 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. To date, however, several randomized controlled trials (RCTs) have shown that once-daily dosing of antipsychotics including perphenazine, risperidone, olanzapine, quetiapine, and asenapine is comparable to twice-daily dosing in terms of efficacy and tolerability, suggesting that once-daily dosing of antipsychotics is a viable option regardless of plasma half-life.

This issue applies to clozapine as well, in that it has a relatively short plasma half-life of 12-16 hours; of note, the product monographs recommends that clozapine be administered more than once daily if the dose exceeds 200 mg/day in Canada. Despite this, in clinical practice clozapine is frequently administered once daily because of convenience and side effects such as a daytime sedation or somnolence, In support of this, a cross-sectional survey done at the investigators' own centre has revealed that clozapine was prescribed once daily in 75.1% of 676 patients, even though \>200 mg/day was administered in 88.6%. 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: Inclusion Criteria:

* 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
* Fluent in English and competent to provide written informed consent

Exclusion Criteria:

* Having significant medical or neurological illnesses
* Pregnant or lactating

Primary outcomes:
measure: Brief Psychiatric Rating 18 item Scale (BPRS 18 item scale)
timeFrame: 0 and 12 weeks
Secondary outcomes:
measure: Glasgow Antipsychotic Side-effect Scale for Clozapine (GASS-C)
timeFrame: 0 and 12 weeks
measure: Brief Evaluation of Psychosis Symptom Domains (BE-PSD)
timeFrame: 0 and 12 weeks
measure: Personal and Social Performance scale (PSP)
timeFrame: 0 and 12 weeks
measure: Clinical Global Impression - Severity of Illness (CGI-S)
timeFrame: 0 and 12 weeks
measure: Brief Neurocognitive Assessment (BNA)
timeFrame: 0 and 12 weeks
measure: Subjective Well-being under Neuroleptics scale - Short form (SWNS)
timeFrame: 0 and 12 weeks
measure: Change in the Visual Analogue Scale for Distress Associated with Symptoms (VAS-DAS) scores from baseline to 12 weeks
timeFrame: 0 and 12 weeks
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Centre for Addiction and Mental Health
state: Ontario
Study officials:
affiliation: Centre for Addiction and Mental Health
name: Gary Remington, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Takeuchi H, Fervaha G, Uchida H, Suzuki T, Bies RR, Gronte D, Remington G. Impact of once- versus twice-daily perphenazine dosing on clinical outcomes: an analysis of the CATIE data. J Clin Psychiatry. 2014 May;75(5):506-11. doi: 10.4088/JCP.13m08695.
citation: Nair NP. Therapeutic equivalence of risperidone given once daily and twice daily in patients with schizophrenia. The Risperidone Study Group. J Clin Psychopharmacol. 1998 Apr;18(2):103-10. doi: 10.1097/00004714-199804000-00002.
citation: Agarwal V, Chadda RK. Once daily risperidone in treatment of schizophrenia. Indian J Psychiatry. 2001 Jan;43(1):32-5.
citation: Takeuchi H, Fervaha G, Lee J, Agid O, Remington G. Effectiveness of different dosing regimens of risperidone and olanzapine in schizophrenia. Eur Neuropsychopharmacol. 2015 Mar;25(3):295-302. doi: 10.1016/j.euroneuro.2014.12.008. Epub 2015 Jan 9.
citation: Chengappa KN, Parepally H, Brar JS, Mullen J, Shilling A, Goldstein JM. A random-assignment, double-blind, clinical trial of once- vs twice-daily administration of quetiapine fumarate in patients with schizophrenia or schizoaffective disorder: a pilot study. Can J Psychiatry. 2003 Apr;48(3):187-94. doi: 10.1177/070674370304800307.
citation: Sun X, Hamer R, McEvoy J. Asenapine once daily versus twice daily: impact on patient acceptance in a randomized, open-label, 14-day clinical trial. J Clin Psychiatry. 2015 Jul;76(7):992-3. doi: 10.4088/JCP.14l09206. No abstract available.
citation: Hiemke C, Baumann P, Bergemann N, Conca A, Dietmaier O, Egberts K, Fric M, Gerlach M, Greiner C, Grunder G, Haen E, Havemann-Reinecke U, Jaquenoud Sirot E, Kirchherr H, Laux G, Lutz UC, Messer T, Muller MJ, Pfuhlmann B, Rambeck B, Riederer P, Schoppek B, Stingl J, Uhr M, Ulrich S, Waschgler R, Zernig G. AGNP Consensus Guidelines for Therapeutic Drug Monitoring in Psychiatry: Update 2011. Pharmacopsychiatry. 2011 Sep;44(6):195-235. doi: 10.1055/s-0031-1286287. Epub 2011 Sep 27.
citation: Takeuchi H, Powell V, Geisler S, DeSanti M, Fervaha G, Agid O, Kane JM, Remington G. Clozapine administration in clinical practice: once-daily versus divided dosing. Acta Psychiatr Scand. 2016 Sep;134(3):234-40. doi: 10.1111/acps.12593. Epub 2016 May 16.