Effect of adenosine A2a receptor blockade on dopamine D2 receptors

Not Applicable

• Conditions: Physically and mentally healthy

• Registration Number: JPRN-jRCTs031180131
• Lead Sponsor: Okita Kyoji

Brief Summary

This is a double-blind, randomized controlled trials aiming to evaluate the effect of instradefylline, a selective adenosine 2A receotor antagonist, compared to placebo on dopamine D2 receptor availability in striatum. The pharmacological intervention was 2 week, and positron emission tomography (PET) scan with 11C-raclopride was performed before and after the intervention. The result shows that istradefylline, compared placebo, increase the striatal D2 receptor availability.

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2019-02-18
• Study Completion: 2021-06-30
• Last Update Posted: 17 October 2023

Recruitment & Eligibility

• Status: Complete
• Sex: Male
• Target Recruitment: 36

Inclusion Criteria

1.Physically and mentally healthy male nonsmokers aged between 20 and 65 (nonsmoker is defined as those who has not smoked for the last one year)
2.No problems with communication in Japanese language and understanding documents of informed consent

Exclusion Criteria

1.Past history of neurological and/or psychiatric disorders
2.Intracranial lesion(s) seen in MRI
3.Impairment of liver and/or renal function
4.HIV seropositive
5.Positive urine-sample test for illegal drug
6.Past history of suicidal ideation or attempt
7.Claustrophobia or aichmophobia
8.MRI imcompatible metals inside the body
9.Use of psychotropic drugs which could have an impact on dopamine D2 receptor availability
10.Engaged in night work
11.Employees of National Center of Neurology and Psychiatry or any companies that have a business connection with National Center of Neurology and Psychiatry
12.Participate in any other clinical trials or studies
13.In case of principle investigator judges inappropriate to participate in the study

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Striatal dopamine D2 receptor availability

Secondary Outcome Measures

Name	Time	Method
eurocognitive measures relating impulsivity, eyelid movement (eyeblinks) and plasma concentration of istradefylline