Conditions

Erectile Dysfunction

Outcome Measures

Change From Baseline in the International Index of Erectile Function - Erectile Function Domain (IIEF-EF) at Week 12
Self-reported erectile function over the past 4 weeks. Scores range from 0 (low or no erectile function) to 5 (high erectile function) on 6 questions (1-5, 15 of the IIEF). Total Erectile Function Domain scores range from 0 to 30.
Baseline, Week 12
Change From Baseline in Question 2 of the Patient Sexual Encounter Profile (SEP) Diary at Week 12 in Percentage of Yes Responses
Assessed was the mean change from baseline in the percentage of Yes responses to the SEP diary Question 2. "Were you able to insert your penis into your partner's vagina?" Data are presented as the mean percentage of yes responses per participant.
Baseline, Week 12
Sexual Encounter Profile (SEP) Diary, Question 3 Change From Baseline to Week 12 in Percentage of Yes Responses
Assessed was the mean change from baseline in the percentage of Yes responses to the SEP diary Question 3. "Did your erection last long enough for you to have successful intercourse?" Data are presented as the mean percentage of yes responses per participant.
Baseline, 12 weeks

Change From Baseline to 12 Week Endpoint in Nocturnal Penile Tumescence (NPT) Pattern: Number of Erectile Events Per Night
Baseline, Week 12
Change From Baseline to 12 Week Endpoint in Nocturnal Penile Tumescence (NPT) Pattern: Duration of Erectile Events Per Night
Baseline, Week 12
Change From Baseline to 12 Week Endpoint in Nocturnal Penile Tumescence (NPT) Pattern: Percentage Volumetric Change
Baseline, Week 12
Change From Baseline to 12 Week Endpoint in the Frequency of Spontaneous Morning Erections Captured by Patient Diary
Baseline, 12 weeks
The Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) Questionnaire at 12 Week Endpoint
Week 12
+10 more secondary outcomes

EXPERIMENTAL

Drug: tadalafil

PLACEBO COMPARATOR

Drug: placebo

5 milligrams (mg) administered orally once a day for 12 weeks

Also known as: Cialis, LY450190

Tadalafil

tablet administered orally once a day for 12 weeks.

Placebo

Age18 Years+

Sexmale

Healthy VolunteersNo

Age GroupsAdult (18-64), Older Adult (65+)

You are male and aged at least 18 years.
Have a history of erectile dysfunction (ED)(defined as the consistent inability to achieve and/or maintain an erection sufficient to permit satisfactory sexual intercourse) of at least 3 months duration.
Agree not to use any other treatment for ED, including herbal and over-the-counter (OTC) medications, during the study
You agree to make at least four sexual intercourse attempts with the female sexual study partner during the 4-week run-in period without medication
Your entry laboratory test results and medical tests meet study requirements
You agree to use the study drug only as instructed by your study doctor and staff and to return any unused study drug and containers at the end of the study or as otherwise instructed by the study doctor.
If currently using cholesterol lowering medications (for example: statins) or medications to lower blood pressure (example: angiotensin-converting enzyme (ACE) inhibitors or calcium channel blocker medications), you need to be on a stable dose and you and your study doctor do not expect any dose change during the study.

You have received previous or current treatment with tadalafil or any other PDE5 inhibitor.
Currently receives treatment with doxazosin, nitrates, cancer chemotherapy, or anti-androgens (except finasteride e.g. Propecia™ or Proscar®, or dutasteride e.g. Avodart®).
You have had significant heart disease as determined by your doctor in charge of this study or a member of the doctor's staff.
Have a history of significant central nervous system injuries (including stroke or spinal cord injury) within the last 6 months.
Have a history of loss of vision in one eye because of nonarteritic anterior ischemic optic neuropathy (NAION), regardless of whether this episode was in connection or not with previous PDE5 inhibitor exposure.

Contact the study team to confirm eligibility.