Official Title: “A Double-Blind, Placebo-Controlled, Randomized, 2-Way Crossover Study to Investigate the Hemodynamic Effects of a Single Dose of Sildenafil (100mg) in Subjects With Benign Prostatic Hyperplasia Being Treated With Doxazosin”

To investigate the effects of a single dose of sildenafil (100 mg) or placebo on blood pressure and pulse rate in subjects taking doxazosin for benign prostatic hyperplasia (BPH).

To investigate the pharmacokinetics of doxazosin when co-administered with sildenafil 100 mg, and to investigate the safety and toleration of sildenafil 100 mg when co-administered with doxazosin.

Study Type: Interventional

Study Design: Basic Science, Randomized, Double Blind (Subject, Investigator), Crossover Assignment, Pharmacokinetics/Dynamics Study

Intervention(s) in this Clinical Trial

• Drug: placebo
  • placebo by mouth as a single dose
• Drug: sildenafil
  • sildenafil 100 mg by mouth as a single dose

Arms, Groups and Cohorts in this Clinical Trial

• Active Comparator: Arm 1
• Placebo Comparator: Arm 2

Primary Measures

• Pharmacodynamic parameters of blood pressure and pulse rate
  • Time Frame: immediately predose, 15, 30, and 45 minutes and 1, 1.5, 2, 2.5, 3, 4, 6, and 8 hours postdose
    Safety Issue?: No

Secondary Measures

• Blood samples for doxazosin pharmacokinetic parameters
  • Time Frame: time 0 (pre-dose), and at 1, 2, 3, 4, 6, and 8 hours post-dose
    Safety Issue?: No
• Safety and toleration of simultaneously co-administering sildenafil and doxazosin.
  • Time Frame: continuous
    Safety Issue?: Yes

Inclusion Criteria:

• patients who weighed between 132 and 220 lb (60 and 100 kg) with benign prostatic hyperplasia (BPH)
• a total PSA (prostate specific antigen) measurement of less than or equal to 10 µg/L within the 12 months prior to screening, were currently on doxazosin treatment for
• BPH, had been treated with doxazosin for a minimum of 2 months prior to first dose of study medication, and had received a minimum of 4 mg doxazosin once daily (from doxazosin supplied for this study) for 2 weeks prior to the first dose of study medication.

Exclusion Criteria:

• subjects with a recent history (i.e. within 6 months prior to screening) of stroke or myocardial infarction
• subjects with severe cardiovascular disorders such as unstable angina or severe congestive heart failure
• subjects with known hereditary degenerative retinal disorders, such as retinitis pigmentosa
• subjects with a supine systolic/diastolic blood pressure of >170/100 mmHg or <100/60 mmHg either at screening or at the pre-dose measurements
• subjects receiving any other antihypertensive therapy other than doxazosin in the 3 weeks prior to the first dose of study medication.

Gender Eligibility for this Clinical Trial: Male

Minimum Age for this Clinical Trial: 35 Years

Maximum Age for this Clinical Trial: 75 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: Pfizer

Overall Clinical Trial Officials and Contacts

Pfizer CT.gov Call Center Study Director Pfizer  

Information obtained from ClinicalTrials.gov on September 05, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00645034

Study ID Number: A1481163

ClinicalTrials.gov Identifier: NCT00645034

Health Authority: United States: Food and Drug Administration

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