Relation Between Intraocular Pressure Lowering Effects of Topical Brimonidine and Alpha 2 Receptor Polymorphism - Full Text View

Sponsored by:	Medical University of Vienna
Information provided by:	Medical University of Vienna
ClinicalTrials.gov Identifier:	NCT00712777

Purpose

Topical brimonidine is a recently introduced alpha 2 receptor agonist which is used in the therapy of intraocular pressure (IOP) reduction in patients with open angle glaucoma. Although adequate IOP reduction is achieved in many patients there is a considerable degree of variability in IOP reduction among subjects. The reason for this interindividual variability is not entirely clear. Obviously differences in pharmacokinetic properties due to variable penetration of the drug through the cornea may be responsible. Alternatively, polymorphisms of the alpha-2 receptor may account for the differences in IOP-lowering efficacy of topical brimonidine. This hypothesis is tested in the present study. Polymorphisms of the alpha-2 receptor have been described in a number of previous studies. In addition, polymorphisms in the alpha-2 receptor gene have been shown to be functionally important, particularly a polymorphism of the alpha-2B receptor, which has a high allele frequency in caucasians.

Condition	Intervention
Ocular Physiology Intraocular Pressure	Drug: Brimonidine 0.2 %

Drug Information available for: Brimonidine Brimonidine Tartrate

U.S. FDA Resources

Study Type:	Interventional
Study Design:	Diagnostic, Open Label, Parallel Assignment, Safety/Efficacy Study
Official Title:	Relation Between Intraocular Pressure Lowering Effects of Topical Brimonidine and Alpha 2 Receptor Polymorphism

Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:

Intraocular pressure (IOP) [ Time Frame: in total 10 minutes ] [ Designated as safety issue: No ]
alpha-2B receptor genotyping [ Time Frame: 20 minutes ] [ Designated as safety issue: No ]

Estimated Enrollment:	80
Study Start Date:	March 2008
Estimated Study Completion Date:	September 2009
Estimated Primary Completion Date:	September 2009 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
1: Active Comparator homozygote mutant: Insertion/Insertion (40 patients)	Drug: Brimonidine 0.2 % Brimonidine 0.2 % (Alphagan, Irvine, CA, USA), dose: 1 drop per eye
2: Active Comparator homozygote mutant: Deletion/Deletion (40 patients)	Drug: Brimonidine 0.2 % Brimonidine 0.2 % (Alphagan, Irvine, CA, USA), dose: 1 drop per eye

Eligibility

Ages Eligible for Study:	19 Years to 35 Years
Genders Eligible for Study:	Male
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

Men aged between 19 and 35 years, nonsmokers
Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
IOP between 12 and 16 mmHg
Normal ophthalmic findings, ametropia < 3 Dpt.
Results of alpha-2B receptor genotyping; subjects who fall within one of the following groups: group 1: homozygote mutant: I/I (n=40); group 2: homozygote mutant: D/D (n=40)

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

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00712777

Contacts

Contact: Gerhard Garhofer, MD

0043 1 40400 ext 2981

klin-pharmakologie@meduniwien.ac.at

Locations

Austria
Department of Clinical Pharmacology	Recruiting
Vienna, Austria, 1090

Sponsors and Collaborators

Medical University of Vienna

More Information

Responsible Party:	Department of Clinical Pharmacology ( Gabriele Fuchsjäger-Mayrl, MD )
Study ID Numbers:	OPHT-230408
Study First Received:	July 8, 2008
Last Updated:	July 9, 2008
ClinicalTrials.gov Identifier:	NCT00712777
Health Authority:	Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:

Brimonidine
alpha 2 receptor polymorphism
Intraocular Pressure

Study placed in the following topic categories:

Brimonidine

Additional relevant MeSH terms:

Neurotransmitter Agents
Adrenergic alpha-Agonists
Molecular Mechanisms of Pharmacological Action
Adrenergic Agents
Therapeutic Uses

Physiological Effects of Drugs
Cardiovascular Agents
Antihypertensive Agents
Pharmacologic Actions
Adrenergic Agonists

ClinicalTrials.gov processed this record on January 14, 2009