Effects of Buspirone Combined with Clozapine

March 25, 2025 updated by: Chuanfu Song

Effects of Different Doses of Buspirone Combined with Clozapine on Psychiatric Symptoms and Cognitive Function in Patients with Schizophrenia: a Randomised, Double-blind, Placebo-controlled Trial

This study aimed to evaluate the enhancing effects of different doses of buspirone on psychiatric symptoms and cognitive function in patients with schizophrenia. The investigators adopted a prospective, randomised, double-blind, placebo-controlled study design and included 46 patients with schizophrenia being treated at the Fourth People's Hospital of Wuhu. The patients were randomly divided into three groups: the control group, the low-dose group and the high-dose group. The control group received clozapine monotherapy, while the experimental groups received additional buspirone at different doses in addition to clozapine. The Positive and Negative Syndrome Scale (PANSS) and the Chinese version of the Repeatable Battery for the Assessment of Neuropsychological Status were used to evaluate psychiatric symptoms and cognitive function.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

46

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Anhui
      • Wuhu City, Anhui, China, 241002
        • Wuhu Fourth People's Hospital affiliated with Bengbu Medical University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 18-65 years;
  • Meeting the diagnostic criteria for chronic schizophrenia in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)
  • Current remission of psychotic symptoms. The patients had a relatively stable mental state in the past 4 weeks, with a total score of ≤60 points and a score of ≤4 points on the Positive and Negative Syndrome Scale (PANSS)[15], and there were no signs of acute psychotic symptoms. To ensure that patients were included in the chronic phase, only patients who had been diagnosed with schizophrenia for ≥1 year were recruited, thus avoiding confusion with acute phase cases;
  • Receiving monotherapy with antipsychotic drugs, such as clozapine.

Exclusion Criteria:

  • Pregnant or lactating women;
  • Patients allergic to buspirone;
  • Patients previously diagnosed with cognitive impairment, such as dementia or intellectual disability;
  • Patients with a history of other brain injuries or diseases, such as stroke, traumatic brain injury, epilepsy or intracranial infection;
  • Patients with severe liver or kidney insufficiency;
  • Patients with severe physical diseases or other mental illnesses, such as bipolar disorder, major depressive disorder, alcohol or substance dependence;
  • Patients with a history of using drugs that affect cognitive function during the study period or those who need to adjust the existing treatment regimen;
  • Patients who are unable to cooperate with cognitive function tests or have poor treatment compliance.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Control group
Patients received oral clozapine (Jiangsu Pharmaceutical Co., Ltd., Approval No. H32022963) in combination with a placebo. Each dose of the placebo was 1 mg, taken three times a day. Use of placebo: This study employed a double-blind design. Patients in the control group received clozapine monotherapy and took a placebo concurrently. The placebo was identical to buspirone tablets in terms of appearance, shape, colour and packaging to guarantee the double-blind nature of the study. The placebo was custom-made by a third-party pharmaceutical company. Its label only stated 'placebo' and was exactly the same as that of buspirone tablets. This design was intended to eliminate the potential impact of the placebo effect on the study results.
Drug: Control group (clozapine, placebo)
Patients received oral clozapine (Jiangsu Pharmaceutical Co., Ltd., Approval No. H32022963) in combination with a placebo. Each dose of the placebo was 1 mg, taken three times a day.
Active Comparator: Low-dose group
Patients received oral buspirone tablets (Jiangsu Enhua Pharmaceutical Co., Ltd., Approval No. H19991024) in combination with clozapine. The total daily dose of buspirone was 15 mg, divided into three administrations. The dose remained unchanged throughout the entire study period.
Drug: Low-dose group (buspirone tablets, clozapine)
Patients received oral buspirone tablets (Jiangsu Enhua Pharmaceutical Co., Ltd., Approval No. H19991024) in combination with clozapine. The total daily dose of buspirone was 15 mg, divided into three administrations. The dose remained unchanged throughout the entire study period.
Experimental: High-dose group
Patients received oral buspirone tablets in combination with clozapine. The initial total daily dose of buspirone was 15 mg, divided into three administrations. One week later, the dose was increased to a total daily dose of 30 mg, also divided into three administrations.
Drug: High-dose group (buspirone tablets, clozapine)
Patients received oral buspirone tablets in combination with clozapine. The initial total daily dose of buspirone was 15 mg, divided into three administrations. One week later, the dose was increased to a total daily dose of 30 mg, also divided into three administrations.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Assessment of psychiatric symptoms
Time Frame: 4 weeks, 8 weeks and 12 weeks
The PANSS was used to evaluate the severity of psychiatric symptoms in schizophrenia. The PANSS is composed of three subscales: Positive Scale, Negative Scale and General Psychopathology Scale. Each item is rated on a scale from 1 to 7, with a total score ranging from 0 to 125; lower scores indicate milder symptoms.
4 weeks, 8 weeks and 12 weeks
Assessment of cognitive function
Time Frame: 4 weeks, 8 weeks and 12 weeks
Cognitive function was assessed using the Chinese version of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)[17]. The RBANS assesses five cognitive domains: immediate memory, visuospatial/constructional abilities, language, attention and delayed memory. Each domain contains specific tasks and scoring criteria.
4 weeks, 8 weeks and 12 weeks
Adverse event records
Time Frame: 4 weeks, 8 weeks and 12 weeks
Throughout the entire study period, detailed records were made of all adverse events reported by patients, including the type of the event, the occurrence time, the duration and the severity level. Particular attention was paid to the potential adverse reactions associated with the combined use of medications, such as drowsiness and dizziness
4 weeks, 8 weeks and 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chuanfu Song

Collaborators

Wuhu Fourth People's Hospital affiliated with Bengbu Medical University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 1, 2022

Primary Completion (Actual)

November 10, 2023

Study Completion (Actual)

December 30, 2023

Study Registration Dates

First Submitted

March 19, 2025

First Submitted That Met QC Criteria

March 25, 2025

First Posted (Actual)

April 2, 2025

Study Record Updates

Last Update Posted (Actual)

April 2, 2025

Last Update Submitted That Met QC Criteria

March 25, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Wuhu4thPeopleH001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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