- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT00463957
The Pharmacological Basis for the Increase in Visual Time Constants Induced by Single Oral Doses of Sildenafil
January 11, 2010 updated by: University of Cambridge
Sildenafil and similar drugs have been used for several years to treat erectile dysfunction.
It has been noticed that in some people, sildenafil causes a subtle increase in the length of time that visual images that we see are retained by the retina.
It is thought that this might be due to an effect of sildenafil on inhibiting an enzyme called phosphodiesterase type 6 (PDE6) which is present in the retina.
By giving single oral doses of sildenafil and a similar drug called tadalafil which has less effect on PDE6, we hypothesise that this is the mechanism of the change in vision caused by sildenafil.
By performing computerised visual test, we plan to compare the effects of sildenafil, tadalafil and placebo tablets on vision in healthy volunteers.
Study Overview
Status
Unknown
Conditions
Intervention / Treatment
Study Type
Interventional
Enrollment
12
Phase
- Not Applicable
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
-
-
-
Cambridge, United Kingdom
- University of Cambridge
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
18 years to 55 years (Adult)
Accepts Healthy Volunteers
Yes
Genders Eligible for Study
Male
Description
Inclusion Criteria:
- Healthy
- Male
- 18-55 years
Exclusion Criteria:
- Significant medical or psychiatric illness
- Cardiac disease
- Hyper or hypotension
- Renal disease
- Liver disease
- Stroke
- Sickle cell anaemia
- Multiple myeloma
- Leukaemia
- Bleeding disorders
- Peyronie's disease
- Priapism
- Subjects receiving prescribed medications
- Subjects with known visual abnormalities other than refractive errors, including retinitis pigmentosa, optic neuropathy
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Diagnostic
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
---|
reaction time
|
visual persistence
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Investigators
- Principal Investigator: Morris J Brown, University of Cambridge
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start
August 1, 2006
Study Registration Dates
First Submitted
April 19, 2007
First Submitted That Met QC Criteria
April 19, 2007
First Posted (Estimate)
April 20, 2007
Study Record Updates
Last Update Posted (Estimate)
January 12, 2010
Last Update Submitted That Met QC Criteria
January 11, 2010
Last Verified
April 1, 2007
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- REC 06/Q0108/200
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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