Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

This study has been completed.
Sponsor:
Information provided by:
Medical University of Vienna
ClinicalTrials.gov Identifier:
NCT00810381
First received: December 17, 2008
Last updated: NA
Last verified: December 2008
History: No changes posted
  Purpose

Glaucoma, one of the most common causes of blindness, is associated with increased intraocular pressure (IOP) and optic nerve head ischemia. Nitrovasodilators are discussed in the treatment of glaucoma. Nitrates relax smooth muscle cells in the vasculature by liberating the vasodilator nitric oxide.

The IOP lowering potential and the vasodilator action in retinal and choroidal vessels of nitrates is still a matter of controversy. Previous studies on the ocular hemodynamic effects of nitrates showed partially contradicting results. In addition the IOP lowering effect of nitrates is still unclear. However, recent studies show that long acting nitrates may preserve optic nerve deterioration and visual field loss.

Therefore, the role of nitrovasodilators in control of ocular blood flow and intraocular pressure has to be elucidated. For this purpose the investigators plan to test the hypothesis that nitrovasodilators improve ocular blood supply to the optic nerve head at doses which do not affect systemic hemodynamics.


Condition Intervention
Glaucoma
Drug: Nitroglycerin
Drug: Isosorbide-Dinitrate
Drug: Sodium-nitroprusside
Drug: Physiologic saline solution (control substance)

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

Resource links provided by NLM:


Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:
  • Optic disc blood flow (laser Doppler flowmetry) [ Time Frame: in total 24x on 4 study days ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Intraocular pressure [ Time Frame: in total 8x in 4 study days ] [ Designated as safety issue: No ]
  • Choroidal blood flow (laser Doppler flowmetry) [ Time Frame: in total 24x on 4 study days ] [ Designated as safety issue: No ]
  • Fundus pulsation amplitude in the macula (laser interferometry) [ Time Frame: in total 24x on 4 study days ] [ Designated as safety issue: No ]
  • Fundus pulsation amplitude in the optic disc (laser interferometry) [ Time Frame: in total 24x on 4 study days ] [ Designated as safety issue: No ]
  • Blood pressure, pulse rate [ Time Frame: on 4 study days ] [ Designated as safety issue: Yes ]

Enrollment: 14
Study Start Date: January 1999
Study Completion Date: June 1999
Primary Completion Date: June 1999 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1

Nitroglycerin: (Perlinganit, Nycomet Heilmittelwerke, Vienna, Austria):

0, 0.25, 0.5, 1, 1.5 and 2 µg/kg/min, each infusion step for 20 minutes

Drug: Nitroglycerin
intravenous infusion; 0, 0.125, 0.25, 0.5, 1 and 2 µg/kg/min; 20 minutes per infusion step
Active Comparator: 2

Isosorbide-Dinitrate: (Isoket 0,1 %, Gebro Broschek, Fieberbrunn, Austria):

0, 0.5, 1, 2, 4 and 6 µg/kg/min , each infusion step for 20 minutes

Drug: Isosorbide-Dinitrate
intravenous infusion; 0, 0.5, 1, 2, 4, and 6 µg/kg/min; 20 minutes per infusion step
Active Comparator: 3

Sodium-Nitroprusside: (Nipruss, Sanol-Schwarz, Monheim, Germany):

0, 0.25, 0.5, 1, 2 and 4 µg/kg/min, each infusion step for 20 minutes

Drug: Sodium-nitroprusside
intravenous infusion; 0, 0.25, 0.5, 1, 2, and 4 µg/kg/min; 20 minutes per infusion step
Placebo Comparator: 4
Physiologic saline solution
Drug: Physiologic saline solution (control substance)
intravenous infusion, infusion period 120 minutes

  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
  • Body mass index between 15th and 85th percentile (Must et al. 1991)
  • 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, ametropia < 3 Dpt.

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
  • History of migraine
  • Blood donation during the previous 3 weeks
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00810381

Locations
Austria
Department of Clinical Pharmacology, Medical University of Vienna
Vienna, Austria, 1090
Sponsors and Collaborators
Medical University of Vienna
Investigators
Principal Investigator: Hans-Georg Eichler, MD Department of Clinical Pharmacology, Medical University of Vienna
  More Information

No publications provided

Responsible Party: Hans-Georg Eichler, MD, Department of Clinical Pharmacology, Medical University of Vienna
ClinicalTrials.gov Identifier: NCT00810381     History of Changes
Other Study ID Numbers: OPHT-211097
Study First Received: December 17, 2008
Last Updated: December 17, 2008
Health Authority: Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:
Nitrovasodilators
ONH blood flow
Choroidal blood flow
Nitroglycerin
Isosorbide Dinitrate
Sodium nitroprusside
Laser-Doppler Flowmetry
Regional Blood Flow

Additional relevant MeSH terms:
Glaucoma
Ocular Hypertension
Eye Diseases
Isosorbide-5-mononitrate
Nitroglycerin
Isosorbide Dinitrate
Nitroprusside
Isosorbide
Vasodilator Agents
Cardiovascular Agents
Therapeutic Uses
Pharmacologic Actions
Diuretics, Osmotic
Diuretics
Natriuretic Agents
Physiological Effects of Drugs
Nitric Oxide Donors
Molecular Mechanisms of Pharmacological Action
Antihypertensive Agents

ClinicalTrials.gov processed this record on April 23, 2014