NCT00463957

Brief 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. 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.

Trial Health

55
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
12

participants targeted

Target at below P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

August 1, 2006

Completed
9 months until next milestone

First Submitted

Initial submission to the registry

April 19, 2007

Completed
1 day until next milestone

First Posted

Study publicly available on registry

April 20, 2007

Completed
Last Updated

January 12, 2010

Status Verified

April 1, 2007

First QC Date

April 19, 2007

Last Update Submit

January 11, 2010

Conditions

Erectile Dysfunction

Keywords

sildenafiltadalafilphosphodiesterasevisual persistencereaction time

Outcome Measures

Primary Outcomes (2)

  • visual persistence

  • reaction time

Interventions

sildenafilDRUG
tadalafilDRUG
placeboDRUG

Eligibility Criteria

Age18 Years - 55 Years
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Healthy
  • Male
  • years

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Cambridge

Cambridge, United Kingdom

Location

MeSH Terms

Conditions

Erectile Dysfunction

Interventions

Sildenafil CitrateTadalafil

Condition Hierarchy (Ancestors)

Genital Diseases, MaleGenital DiseasesUrogenital DiseasesSexual Dysfunction, PhysiologicalMale Urogenital DiseasesSexual Dysfunctions, PsychologicalMental Disorders

Intervention Hierarchy (Ancestors)

SulfonamidesAmidesOrganic ChemicalsSulfonesSulfur CompoundsPiperazinesHeterocyclic Compounds, 1-RingHeterocyclic CompoundsPurinesHeterocyclic Compounds, 2-RingHeterocyclic Compounds, Fused-RingCarbolinesPyridinesIndole AlkaloidsIndolesHeterocyclic Compounds, 3-Ring

Study Officials

  • Morris J Brown

    University of Cambridge

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Purpose
DIAGNOSTIC
Intervention Model
PARALLEL
Sponsor Type
OTHER

Study Record Dates

First Submitted

April 19, 2007

First Posted

April 20, 2007

Study Start

August 1, 2006

Last Updated

January 12, 2010

Record last verified: 2007-04

Locations

GB(1)