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

This study has been completed.
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ClinicalTrials.gov Identifier:
First received: March 20, 2008
Last updated: March 26, 2008
Last verified: March 2008
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.

Condition Intervention Phase
Benign Prostatic Hyperplasia
Drug: placebo
Drug: sildenafil
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
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

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome 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 ] [ Designated as safety issue: No ]

Secondary Outcome 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 ] [ Designated as safety issue: No ]
  • Safety and toleration of simultaneously co-administering sildenafil and doxazosin. [ Time Frame: continuous ] [ Designated as safety issue: Yes ]

Enrollment: 20
Study Start Date: November 2002
Study Completion Date: July 2003
Arms Assigned Interventions
Active Comparator: Arm 1 Drug: sildenafil
sildenafil 100 mg by mouth as a single dose
Placebo Comparator: Arm 2 Drug: placebo
placebo by mouth as a single dose


Ages Eligible for Study:   35 Years to 75 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No

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.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00645034

United States, California
Pfizer Investigational Site
Laguna Woods, California, United States, 92653
Pfizer Investigational Site
Newport Beach, California, United States, 92660
Sponsors and Collaborators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
Responsible Party: Director, Clinical Trial Disclosure Group, Pfizer, Inc.
ClinicalTrials.gov Identifier: NCT00645034     History of Changes
Other Study ID Numbers: A1481163 
Study First Received: March 20, 2008
Last Updated: March 26, 2008
Health Authority: United States: Food and Drug Administration

Additional relevant MeSH terms:
Prostatic Hyperplasia
Genital Diseases, Male
Pathologic Processes
Prostatic Diseases
Cardiovascular Agents
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Phosphodiesterase 5 Inhibitors
Phosphodiesterase Inhibitors
Therapeutic Uses
Urological Agents
Vasodilator Agents

ClinicalTrials.gov processed this record on May 05, 2016