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Effects of Buspirone Combined With Clozapine

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

Status
Completed
Phases
Early Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06906224
Enrollment
46
Registered
2025-04-02
Start date
2022-05-01
Completion date
2023-12-30
Last updated
2025-04-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia

Keywords

Buspirone, schizophrenia

Brief summary

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.

Interventions

DRUGControl 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.

DRUGLow-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.

DRUGHigh-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.

Sponsors

Wuhu Fourth People's Hospital affiliated with Bengbu Medical University
CollaboratorOTHER
Chuanfu Song
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)

Eligibility

Sex/Gender
ALL
Age
1 Years to 65 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Assessment of psychiatric symptoms4 weeks, 8 weeks and 12 weeksThe 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.
Assessment of cognitive function4 weeks, 8 weeks and 12 weeksCognitive 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.
Adverse event records4 weeks, 8 weeks and 12 weeksThroughout 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

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026