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Evaluation of Tolcapone as a Cognitive Enhancer in Schizophrenia

Phase 2
Recruiting
Conditions
Schizophrenia
Interventions
Registration Number
NCT06387771
Lead Sponsor
Clinica Universidad de Navarra, Universidad de Navarra
Brief Summary

Objective: To assess the efficacy of tolcapone to improve cognition in schizophrenia, as a genotype-based targeted treatment of cognitive and negative symptoms of schizophrenia considering the polymorphism rs4680.

Methodology: 20 patients with chronic and stabilized schizophrenia (10 patients with genotype Val/Val and 10 patients with genotype Met/Met according to polymorphism rs4680) will receive treatment with tolcapone during 7 days. The cognitive function and clinical status will be evaluated with a neuropsychological battery and appropriate clinical scales before and after treatment. The efficiency of the activation of the prefrontal cortex will be measured using functional magnetic resonance imaging (fMRI) before and after treatment.

Hypothesis: Only patients with genotype Val/Val treated with tolcapone would show a cognitive improvement, a higher efficiency of the activation of the prefrontal cortex and an amelioration of some negative symptoms.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
20
Inclusion Criteria
  • Ability to give informed consent and express the wish to fulfill all the requirements of the protocol during the study period.
  • The patient must be capable of fulfillment of all the requirements of the clinical trial, at the investigator's discretion.
  • Patients diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). Only chronic patients will be recruited, and they must be clinically compensated in order to consent to participate. The determination of clinical compensation will be conducted according with these criteria: i) outpatients, with absence of hospitalization due to acute psychiatric decompensation in the previous year, and ii) maintained GAF score equal or higher than 60 during the previous month. The recruitment process will include a clinical interview to verify the diagnosis.
  • Caucasic ethnicity
  • Negative pregnancy test for women of childbearing age.
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Exclusion Criteria
  • Severe infections or diseases or hepatic failure (or increased liver enzymes), renal failure or bone marrow failure that advise against participation in the study at the investigator's discretion
  • Positive pregnancy test, or breastfeeding women.
  • Carriers of pacemaker or any kind of metallic prosthesis incompatible with magnetic resonance imaging.
  • History of hypersensitivity to Tasmar® (tolcapone) or to any of its components
  • Active (in the last 12 months) substance abuse, or other disease that causes psychiatric symptoms
  • Cardiovascular disease and electrocardiogram alterations
  • Patients receiving treatment with monoamine oxidase inhibitors during the study or up to 15 days prior to the beginning of the study.
  • Patients receiving treatment with a catechol-O-methyltransferase (COMT) inhibitor
  • Participation in another clinical trial in the previous 30 days.
  • Other circumstances which involve Tasmar® (tolcapone) contraindications: history of Neuroleptic Malignant Syndrome and/or non-traumatic rhabdomyolysis or hyperthermia. Severe dyskinesia. Phaeochromocytoma. Hereditary galactose intolerance. Lapp lactase deficiency or glucose or galactose malabsorption.
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Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
TolcaponeTolcaponeTolcapone (Film-coated tablet) 200 mg orally every 8 hours for 7 days
Primary Outcome Measures
NameTimeMethod
Efficacy: Change from baseline in cognitive test scores at day 8Day 8

Performance in the cognitive tests scores: Dot Pattern Expectancy Task and cognitive tests (including subtests of the MATRICS\* battery) (\*MATRICS=Measurement and Treatment Research to Improve Cognition in Schizophrenia cognitive battery established by the National Institute of Mental Health) .

Efficacy: Change from baseline in the brain blood-oxygen-level-dependent (BOLD) response at day 8Day 8

Elicited brain activation during functional magnetic resonance neuroimaging (relative degree of activation of different brain regions) measured by BOLD signal.

Secondary Outcome Measures
NameTimeMethod
Efficacy: change from baseline in psychotic symptoms intensity measured by the PANSS scores at day 8Day 8

Change in psychotic symptoms intensity measured by the PANSS symptom scores

Efficacy: negative symptoms intensity: change from baseline in the 16-item Negative Symptom Assessment (NSA-16) scale scores at day 8Day 8

Change in negative symptoms intensity measured by the NSA-16 scale

Efficacy: change from baseline in the global assessment of functioning measured by the Global Assessment of Functioning (GAF) scale scores at day 8Day 8

Clinical outcome measured by the change in the scores on the GAF scale

Efficacy: change from baseline in the Clinician-Rated Dimensions of Psychosis Symptom Severity (CRDPSS) scale scores at day 8Day 8

Clinical outcome measured by the change in the scores on the CRDPSS scale

Efficacy: change from baseline in the intensity of psychotic symptoms measured by the Brief Psychiatric Rating Scale (BPRS) scores at day 8Day 8

Clinical outcome measured by the change in the scores on the BPRS

Efficacy: change from baseline in the clinical global impression measured by the Clinical Global Impression (CGI) scale scores at day 8Day 8

Clinical outcome measured by the change in the scores on the CGI scale

Efficacy: change from baseline in the anxiety symptoms measured by the Hamilton Anxiety Rating Scale (HAM-A) scale scores at day 8Day 8

Clinical outcome measured by the change in the scores on the HAM-A scale

Efficacy: change from baseline in the depressive symptoms measured by the Hamilton Depression Rating Scale (HAM-D) scale scores at day 8Day 8

Clinical outcome measured by the change in the scores on the HAM-D scale

Change from baseline in plasmatic homocysteine (umol/L)Day 8

Clinical outcome measured by the change in homocystinemia (umol/L)

Trial Locations

Locations (1)

Clinica Universidad de Navarra

🇪🇸

Pamplona, Navarra, Spain

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