Study to Determine Safety and Effectiveness of Tadalafil on Prostate Related Sex Organ/Urinary Tract Problems

A Multicenter, Parallel-Arm, Placebo-Controlled, Double-Blind Study to Evaluate the Efficacy and Safety of Tadalafil Administered Once Daily to Men With Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia

Study to look at safety and effectiveness of different doses of tadalafil on prostate related genital/urinary tract problems.

Inclusion Criteria:

• 6 month history of lower urinary tract symptoms either obstructive and/or irritative secondary to prostate related problems as diagnosed by a urologist.
• Stopped using treatments at least four weeks prior to study and agree to not use any other treatments during the study.
• Meet required prostate symptom score and urine flow rate.

Exclusion Criteria:

• Serum prostate specific antigen (PSA) greater than 10 (between 4 and 10, inclusive, without a negative biopsy w/in the last 6 months.
• Prostate removal and various other pelvic surgeries.
• Neurological disease or condition known to affect the bladder.
• Clinical evidence of prostate cancer, urinary tract inflammation or infection, including prostatitis.
• Have taken medications such as nitrates, finasteride, or dutasteride within the year.