Clinical Trial of Dipyridamole in Schizophrenia

Brief Summary

Official Title: “Clinical Trial of Dipyridamole in Schizophrenia”

This is a 6-week, randomized, double blind, parallel groups designed, olanzapine-controlled trial of oral dipyridamole in symptomatic patients with a (DSM IV) diagnosis of schizophrenia, schizoaffective or schizophreniform disorder. This pilot study aims to provide preliminary estimates of whether the effect sizes of dipyridamole on positive symptoms, negative symptoms, and cognitive deficits differ between schizophrenia patients treated with dipyridamole, and schizophrenia patients treated with olanzapine. A total of 30 subjects will be recruited locally.

  • Study Type: Interventional
  • Study Design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
  • Study Primary Completion Date: September 2008

Detailed Clinical Trial Description

Since the demonstrated success of chlorpromazine in treating psychosis in the1950's, the pharmacotherapy of schizophrenia has focused mainly on drugs with antidopaminergic actions. These drugs have robust effects on reality distortion and disorganization symptom complexes, but minimal effect on cognitive impairment, negative symptoms, and functional outcome and quality of life measures. Newer generation antipsychotic drugs have a similar profile of effects, with some advantages on the course of depression, hostility, suicide, hospital readmission rates and motor side effect measures. Side effects such as weight gain, increase in cardiovascular stress and diabetes risk are associated with some new generation drugs. A new class of drugs is needed to address the inadequate effectiveness and the side-effect disadvantages of the currently available pharmacological agents for the treatment of schizophrenia. Recently, new treatment strategies using nicotinergic drugs or agonists at the glycine modulatory site of the glutamatergic N-methyl-D-aspartate (NMDA) receptor have been employed in clinical trials with mixed results. Our proposal focuses on a clinically available adenosine agonist, dipyridamole, in a 6-week clinical trial. Published data suggest effectiveness of dipyridamole in treating psychosis when added to haloperidol treatment. The effectiveness of dipyridamole alone in treating schizophrenia symptoms, although indirectly suggested by several lines of evidence, has not been tested.

Interventions Used in this Clinical Trial

  • Drug: Dipyridamole
    • Week 1- 50 mg bid Week 2- 50 mg am and 100 mg pm Weeks 3-6 100 mg am and 100 mg pm
  • Other: Olanzapine
    • Week 1- 5 mg BID Week 2- 5 mg am and 10 mg pm Weeks 3-6 10 mg am and 10 mg pm

Arms, Groups and Cohorts in this Clinical Trial

  • Experimental: 1
    • Dipyridamole
  • Active Comparator: 2
    • Olanzapine

Outcome Measures for this Clinical Trial

Primary Measures

  • To provide preliminary estimates of effect sizes of dipyridamole on positive symptoms, negative symptoms, and cognitive deficits differ between schizophrenia patients treating with dipyridamole, and schizophrenia patients treated with olanzapine.
    • Time Frame: 6 weeks
      Safety Issue?: Yes

Secondary Measures

  • To determine if dipyridamole, a clinically available adenosine agonist, has efficacy for treating positive and negative symptoms and cognitive deficits of schizophrenia.
    • Time Frame: 6 weeks
      Safety Issue?: Yes

Criteria for Participation in this Clinical Trial

Inclusion Criteria

  • Subjects between ages 18-65, both males and nonpregnant females (on birth control) Diagnosis of schizophrenia, schizoaffective or schizophreniform disorder Ability to give written informed consent Total BPRS score > 27 Psychosis subscale scores > 7

Exclusion Criteria

  • Patients with coagulative disorders, bleeding diathesis or currently on anticoagulants, and patients with major medical illnesses (including hypertension, angina, and cardiovascular diseases) or an abnormal baseline ECG.

Patients with moderate to severe mental retardation.

Inability to sign informed consent.

Patients with a history of serious violence (e.g., suicide attempts, or assaultive behavior).

Patients on clozapine treatment within the 6 weeks leading to the double-blind phase.

Patients with a history of olanzapine non-response

Positive Urine Toxicology Screen

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 65 Years

Are Healthy Volunteers Accepted for this Clinical Trial: No

Clinical Trial Investigator Information

  • Lead Sponsor
    • University of Maryland
  • Provider of Information About this Clinical Study
    • Principal Investigator: Human Research Protections Office, Associate Professor – University of Maryland
  • Overall Official(s)
    • Ikwunga Wonodi, MD, Study Director, Maryland Pschiatric Research Center, University of Maryland School of Medicine
    • Gunvant K Thaker, MD, Principal Investigator, University of Maryland

Citations Reporting on Results

Akhondzadeh S, Shasavand E, Jamilian H, Shabestari O, Kamalipour A. Dipyridamole in the treatment of schizophrenia: adenosine-dopamine receptor interactions. J Clin Pharm Ther. 2000 Apr;25(2):131-7.

Dixon DA, Fenix LA, Kim DM, Raffa RB. Indirect modulation of dopamine D2 receptors as potential pharmacotherapy for schizophrenia: I. Adenosine agonists. Ann Pharmacother. 1999 Apr;33(4):480-8. Review.

Ferre S. Adenosine-dopamine interactions in the ventral striatum. Implications for the treatment of schizophrenia. Psychopharmacology (Berl). 1997 Sep;133(2):107-20. Review.

Source

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The URL of this page is:
http://clinicaltrialsfeeds.org/clinical-trials/show/NCT00349973