Relation Between Intraocular Pressure Lowering Effects of Topical Brimonidine and Alpha 2 Receptor Polymorphism
Information source: Medical University of Vienna
ClinicalTrials.gov processed this data on August 20, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Ocular Physiology; Intraocular Pressure
Intervention: Brimonidine 0.2 % (Drug)
Phase: N/A
Status: Withdrawn
Sponsored by: Medical University of Vienna
Summary
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.
Clinical Details
Official title: Relation Between Intraocular Pressure Lowering Effects of Topical Brimonidine and Alpha 2 Receptor Polymorphism
Study design: Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Primary outcome: Intraocular pressure (IOP)alpha-2B receptor genotyping
Eligibility
Minimum age: 19 Years.
Maximum age: 35 Years.
Gender(s): Male.
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
Locations and Contacts
Department of Clinical Pharmacology, Vienna 1090, Austria
Additional Information
Starting date: March 2008
Last updated: November 20, 2014
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