Effects of Intravenous Clonidine on Ocular Blood Flow and Intraocular Pressure

NCT00279253 | Completed Phase 4

• 1 other identifier: OPHT-141003
• Study Type: interventional
• Target: 12
• Locations: 0 countries
• Sites: N/A

Brief Summary

Background Clonidine, a derivate of Imidazol, is an antihypertensive drug. It acts by stimulating adrenergic receptors on nerves in the brain and Imidazol-receptors. As a result, clonidine slows the heart rate and reduces blood pressure. Clonidine was approved by the FDA in 1974 and is registered in Austria with the brand name "Catapresan". Alpha2 adrenergic agonists are nowadays used topically as eye drops in glaucoma treatment. In addition to their known effect of lowering intraocular pressure, alpha2 adrenoceptor agonists are neuroprotective. Brimonidine, which is the most commonly used topical alpha-2 agonist, is currently on the market for treatment of glaucoma and is effective in reducing intraocular pressure. 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. Direct investigation of the ocular hemodynamic effects of brimonidine is, however, difficult, because lowering intraocular pressure with brimonidine may confound the results due to the concomitant change in ocular perfusion pressure. The aim of the present study is to assess the effect of intravenous clonidine as model drug of alpha agonists on ocular blood flow and IOP in healthy humans. Study objectives: To investigate effects of clonidine on ocular blood flow and intraocular pressure.

Conditions

Physiology

Keywords

clonidine; glaucoma

Outcome Measures

Primary Outcomes (1)

• ocular blood flow

Interventions

clonidine (drug) intravenously DRUG

Eligibility Criteria

• Age: 19 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Men aged between 19 and 35 years, nonsmokers
• Body mass index between 15th and 85th percentile
• Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
• Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant
• Normal ophthalmic findings, ametropy \< 3 Dpt.

You may not qualify if:

• 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

Sponsors & Collaborators

• Medical University of Vienna: lead

MeSH Terms

Conditions

Glaucoma

Interventions

Clonidine; Pharmaceutical Preparations

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Imidazolines; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Gabriele Fuchsjaeger-Mayrl, MD

  Department of Clinical Pharmacology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: January 18, 2006
• First Posted: January 19, 2006
• Study Start: March 1, 2004
• Study Completion: January 1, 2005
• Last Updated: January 19, 2006

Record last verified: 2006-01