COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Clinical Trial of Dipyridamole in Schizophrenia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00349973
Recruitment Status : Completed
First Posted : July 10, 2006
Results First Posted : December 10, 2018
Last Update Posted : November 4, 2019
Information provided by (Responsible Party):
L. Elliot Hong, University of Maryland, Baltimore

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Schizophrenia Schizoaffective Disorder Schizophreniform Disorder Drug: Dipyridamole Other: Olanzapine Not Applicable

Detailed 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.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 29 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Clinical Trial of Dipyridamole in Schizophrenia
Study Start Date : May 2001
Actual Primary Completion Date : September 2008
Actual Study Completion Date : September 2011

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Schizophrenia

Arm Intervention/treatment
Experimental: 1
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

Active Comparator: 2
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

Primary Outcome Measures :
  1. Change in Positive Symptoms by Treatment Assignment [ Time Frame: Baseline and follow-up ]
    The Brief Psychiatric Rating Scale (BPRS) consists of 20 items, with 6 of these items used to assess positive symptom change. The BPRS positive symptom items are: somatic concern, conceptual disorganization, hostility, suspiciousness, hallucinatory behavior, and unusual thought content. Each scale ranges from "1=Not Present" to "7=Very Severe". A higher score indicates a more severe positive symptom rating.

  2. Change in Negative Symptoms by Treatment Assignment [ Time Frame: Baseline and Follow-Up ]
    The Scale for the Assessment of Negative Symptoms (SANS) total score, minus the global items, inappropriate affect, poverty of content of speech, and attention items, used to measure negative symptoms. Mean SANS total score by treatment and week. SANS total score range = 0-85. Higher scores indicate more severe negative symptoms.

  3. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) [ Time Frame: Baseline and Follow-Up ]
    The RBANS is a brief, individually administered test designed to evaluate neuropsychological status of adults, ages 20-89. The 12 subtests measure attention, language, visuospatial/constructional abilities, and immediate and delayed memory. The raw scores from the subtests are scaled together to create index scores, and these are summed for conversion to a total scale score. Higher score equals a better outcome. The total index score range for the RBANS is 40-160.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00349973

Layout table for location information
United States, Maryland
Maryland Psychiatric Research Center
Baltimore, Maryland, United States, 21228
Sponsors and Collaborators
University of Maryland, Baltimore
Layout table for investigator information
Study Director: Ikwunga Wonodi, MD Maryland Pschiatric Research Center, University of Maryland School of Medicine
Principal Investigator: Gunvant K Thaker, MD University of Maryland, College Park
Additional Information:
Publications of Results:
Layout table for additonal information
Responsible Party: L. Elliot Hong, Associate Professor, University of Maryland, Baltimore Identifier: NCT00349973    
Other Study ID Numbers: HP-00043347
First Posted: July 10, 2006    Key Record Dates
Results First Posted: December 10, 2018
Last Update Posted: November 4, 2019
Last Verified: October 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by L. Elliot Hong, University of Maryland, Baltimore:
Positive symptoms
Negative symptoms
Cognitive deficits
Additional relevant MeSH terms:
Layout table for MeSH terms
Psychotic Disorders
Pathologic Processes
Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Gastrointestinal Agents
Antipsychotic Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
Serotonin Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Serotonin Agents
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Platelet Aggregation Inhibitors
Vasodilator Agents