Effects of Topical Clonidine vs. Brimonidine on Choroidal Blood Flow and Intraocular Pressure During Isometric Exercise

February 9, 2007 updated by: Medical University of Vienna

Brimonidine tartrate is an alpha-2 agonist ocular hypotensive drug that exerts its effect by causing both a decrease in aqueous production and an increase in uveoscleral outflow. It has been proven to reduce increased intraocular pressure in glaucoma and ocular hypertension. As an alpha 2 agonist Brimonidine belongs to the same class of drugs as Clonidine; however, its molecular structure is sufficiently different to make it more selective for the alpha 2 receptor than Clonidine. Unlike Clonidine, Brimonidine does not appear to have an effect on the central nervous system and therefore does not cause sedation or systemic hypotension.

In addition to their known effect of lowering intraocular pressure, alpha 2 adrenoceptor agonists are neuroprotective. It has, however, been shown that Brimonidine is a very potent vasoconstrictor in the ciliary body thus reducing aqueous humor production. Little is, however, known about potential vasoconstrictor effects of Brimonidine in the posterior pole of the eye. This is of clinical importance, because optic nerve head ischemia appears to contribute to glaucoma pathophysiology.

This study is performed to investigate the effects of topical Clonidine vs. topical Brimonidine on choroidal blood flow and intraocular pressure during isometric exercise.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment

18

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Austria
      • Vienna, Austria, 1090
        • Department of Clinical Pharmacology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

19 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Men aged between 19 and 35 years, nonsmokers
  • Body mass index between 15th and 85th percentile (Must A et al. 1991)
  • Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropy < 3 Dpt.
  • Intraocular pressure between 10 and 18 mmHg.

Exclusion Criteria:

  • Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
  • Treatment in the previous 3 weeks with any drug
  • Symptoms of a clinically relevant illness in the 3 weeks before the first study day
  • History of hypersensitivity to the trial drug or to drugs with a similar chemical structure
  • History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with, distribution, metabolism or excretion of study drugs
  • Blood donation during the previous 3 weeks
  • History or family history of epilepsy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Choroidal pressure-flow relationship

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University of Vienna

Investigators

  • Principal Investigator: Gabriele Fuchsjäger-Mayrl, M.D., Deapartment of Clinical Pharmacology, Medical University of Vienna

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2004

Study Completion

December 1, 2004

Study Registration Dates

First Submitted

April 6, 2006

First Submitted That Met QC Criteria

April 7, 2006

First Posted (Estimate)

April 10, 2006

Study Record Updates

Last Update Posted (Estimate)

February 12, 2007

Last Update Submitted That Met QC Criteria

February 9, 2007

Last Verified

February 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OPHT-121203B

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Ocular Physiology

Clinical Trials on Brimonidine

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Cyprus

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe