"Extended" (Alternate Day) Antipsychotic Dosing

Schizophrenia and Related Disorders Clinical Trial

Official title: "Re-examining Maintenance Antipsychotic Treatment in Schizophrenia: "Extended" Antipsychotic Dosing"

Status Recruiting

Clinical Trial Summary

The study wishes to examine whether "extended" antipsychotic treatment, in this case, antipsychotic treatment every other day, is as effective as daily treatment. It is also evaluating whether there may be differences in terms of side effects.

Participants will be randomly assigned to either the treatment as usual group (i.e., taking antipsychotic daily) or the extended dosing group (i.e., taking antipsychotic one day on, one day off). That means, like flipping a coin, there is a 50/50 chance that participants will continue on daily dosing of your antipsychotic or have it switched to every other day dosing.

This study will last for 1 year. Participants will be evaluated at the beginning and every two weeks during the first 6 months, with visits once every 4 weeks for the final 6 months. In total, participants will make 22 visits over 52 weeks to the investigator's office.

The investigators hypothesize that with ED, there will be no change in symptom severity but improvement in the frequency and severity of side effects, wellbeing, and functioning.

Clinical Trial Description

This is a randomized, double-blind, controlled trial that will compare ED, i.e. alternate day dosing to daily dosing i.e. TAU.

Individuals will be randomized to ED or TAU using a permuted block design with a random number generator. The size will be fixed and study personnel blinded to the randomization block size.

To maintain a double-blind design, our pharmacy will provide, on an individualized basis, APs at the appropriate dose and placebo where necessary in matching gelatin capsules, packaged in blister packs. The active tablet will be over-encapsulated, and matching placebo will be prepared using the same capsules (filled with lactose). Thus, from the individual subject's position, AP treatment is continued according to the same daily schedule. Further, if their current medication is prescribed in divided doses, this too will be employed during the study. The minimum and maximum doses for Risperidone will be 1 mg and 16mg respectively. The minimum and maximum doses for Olanzapine will be 5 mg and 20mg respectively. Other psychotropic medications prescribed before the study will be permitted, with any changes in dosing during its course documented

The trial is 1 year in duration. To prevent bias, the study code will remain blinded until the trial's completion.

Study visits will be scheduled every 2 weeks over the first 6 months, in line with the earlier investigation. Thereafter, the visits will be decreased to every 4 weeks, aligning with the schedule routinely observed in our ambulatory clinics.

The investigators are asking the following questions:

1. (Non-inferiority) Can additional confirmatory evidence support "extended" AP dosing (ED) as an alternative to continuous administration, i.e. is it as effective clinically?

2. (Superiority) Can the investigators establish clinical benefits (e.g. better tolerability, fewer side effects, such as decreased glucose dysregulation) with ED?

Hypothesis: The investigators hypothesize that with ED, there will be no change in symptom severity but improvement in the frequency and severity of side effects, wellbeing, and functioning. ;

Related Conditions & MeSH terms

• Antipsychotic Agents
• Drug Administration Schedule
• Drug Therapy
• Schizophrenia
• Schizophrenia and Related Disorders

• NCT number: NCT04478838
• Study type: Interventional
• Source: Centre for Addiction and Mental Health
• Contact: Carol Borlido
• Phone: 416-535-8501
• Email: carol.borlido@camh.ca
• Status: Recruiting
• Phase: Phase 4
• Start date: June 6, 2022
• Completion date: September 30, 2028