A Study to Investigate the Effects on Blood Pressure and Pulse Rate of a Single 100mg Dose of Sildenafil in Patients With Benign Prostatic Hyperplasia Who Are Being Treated With Doxazosin

Study Overview
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Brief Summary
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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.

Official Title
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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

Conditions
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Benign Prostatic Hyperplasia

Intervention / Treatment
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* Drug: placebo
* Drug: sildenafil


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Arm 1<br> | Drug: sildenafil<br>* sildenafil 100 mg by mouth as a single dose<br>|
| Placebo Comparator: Arm 2<br> | Drug: placebo<br>* placebo by mouth as a single dose<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pharmacodynamic parameters of blood pressure and pulse rate |  | immediately predose, 15, 30, and 45 minutes and 1, 1.5, 2, 2.5, 3, 4, 6, and 8 hours postdose | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood samples for doxazosin pharmacokinetic parameters |  | time 0 (pre-dose), and at 1, 2, 3, 4, 6, and 8 hours post-dose | 
| Safety and toleration of simultaneously co-administering sildenafil and doxazosin. |  | continuous |