Treatment of Erectile Dysfunction I

Inclusion Criteria:

• Male, at least 19 years of age

• Stable monogamous relationship for at least 6 months with a consenting female partnerwho is at least 19 years of age, vaginal intercourse is a required study activity

• History of ED (clinically defined as the inability to attain and maintain an erectionof the penis sufficient to permit satisfactory sexual intercourse) of at least 3months duration

• Partner is not pregnant or lactating

Exclusion Criteria:

• History of new-onset symptomatic coronary artery disease within the last 3 months or ahistory of myocardial infarction or cardiac surgical procedure within six months

• Cardiac arrhythmias requiring antiarrhythmic treatment

• Symptomatic congestive heart failure

• Taking nitrate medication in any form

• Uncontrolled diabetes (HbA1c ≥ 13%)

• Hypersensitivity to phosphodiesterase type 5 (PDE-5) inhibitors such as Viagra®,Cialis® or Levitra®

• Previously failed to respond to PDE-5 inhibitors such as Viagra®, Cialis® or Levitra®