Effects of Topical Clonidine vs. Brimonidine on Choroidal Blood Flow and Intraocular Pressure During Isometric Exercise
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|ClinicalTrials.gov Identifier: NCT00312416|
Recruitment Status : Completed
First Posted : April 10, 2006
Last Update Posted : February 12, 2007
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.
|Condition or disease||Intervention/treatment||Phase|
|Ocular Physiology Regional Blood Flow||Drug: Clonidin Drug: Brimonidine||Phase 4|
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||18 participants|
|Intervention Model:||Crossover Assignment|
|Official Title:||Effects of Topical Clonidine vs. Brimonidine on Choroidal Blood Flow and Intraocular Pressure During Isometric Exercise|
|Study Start Date :||February 2004|
|Estimated Study Completion Date :||December 2004|
- Choroidal pressure-flow relationship
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00312416
|Department of Clinical Pharmacology|
|Vienna, Austria, 1090|
|Principal Investigator:||Gabriele Fuchsjäger-Mayrl, M.D.||Deapartment of Clinical Pharmacology, Medical University of Vienna|