Erectile DysfunctionNCT00463957
The Pharmacological Basis for the Increase in Visual Time Constants Induced by Single Oral Doses of Sildenafil
A study testing sildenafil and tadalafil in people with Erectile Dysfunction, run by University of Cambridge at 1 site in United Kingdom.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 55 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Erectile Dysfunction
- What is being tested?
- sildenafil and tadalafil
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Aug 2006to not given
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy
- Male
- 18-55 years
Who cannot join
- Significant medical or psychiatric illness
- Cardiac disease
- Hyper or hypotension
- Renal disease
- Liver disease
- Stroke
Show all 14Show fewer
- 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
Trial locations and contacts
1 site in 1 country.
About this study
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.
- Conditions
- Erectile Dysfunction
- Being tested
- sildenafil, tadalafil, placebo
- Keywords
- sildenafil, tadalafil, phosphodiesterase, visual persistence, reaction time
- Medical subject headings
- Erectile Dysfunction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
sildenafilDrug
tadalafilDrug
placeboDrug
What is being measured
The primary outcome is the main question the study is designed to answer.
visual persistence
reaction time
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Apr 2007 (estimated)
- Study startAug 2006
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Erectile DysfunctionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Enrolment
- 12 participants
Sponsor and investigators
- Lead sponsor
- University of Cambridge
- Sponsor type
- University, hospital or other
- Investigators
- Morris J Brown, Principal investigator, University of Cambridge
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00463957
- Sponsor's protocol ID
- REC 06/Q0108/200
- Status last verified
- Apr 2007
- First submitted
- 19 Apr 2007
- Last updated
- 12 Jan 2010
- Results posted
- No
- Data monitoring committee
- No