Effects of Yohimbine and Naltrexone on Sexual Function

Effects of Alpha-2 Adrenergic and Opiate Receptor Blockade on Sexual Function in Healthy Male Volunteers

The purpose of this study is to evaluate the safety and effectiveness of the drugs yohimbine and naltrexone in treating men with erectile dysfunction (ED) (the inability to achieve or maintain penile erection for satisfactory sexual performance).

ED is a medical and psychological problem that is usually associated with increased age. Evidence suggests that specific neurotransmitter systems are involved in the regulation of sexual function. Yohimbine and naltrexone are drugs that may influence these neurotransmitter systems. This study will use different doses of yohimbine and fixed doses of naltrexone to determine their effectiveness in treating ED.

Participants in this study will be screened with a medical history, physical examination, blood and urine tests, and an electrocardiogram (ECG). The study will consist of three outpatient visists.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

Erectile dysfunction (ED) is a relevant medical and psychological problem for males, and is usually associated with increased age. There is substantial evidence available suggesting that noadrenergic and opiate transmitter systems are involved in regulation of sexual function. The objective of the present study is to evaluate the effects and safety of a potential novel treatment combination for ED consisting of both, the alpha-adrenoreceptor antagonist yohimbine, and the opiate antagonist naltrexone. The study uses a three-phase, double-blind, placebo-controlled cross-over design. Healthy, male volunteers will participate. The effects of differing dosages of yohimbine (10 mg versus 20 mg) and a fixed dose of naltrexone (50 mg) on penile tumescene and rigidity, and sexual arousal are assessed in a placebo-controlled design. The anticipated risks of the study are considered minimal in relation to the importance of our increased knowledge about regulation of physiological and psychological aspects of regulation of sexual function and dysfunction. This novel treatment combination could be later also applied to patients with ED of different origin, e.g. organic, psychogenic, and mixed causes.

Study Type

Observational

Enrollment

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institute of Mental Health (NIMH)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

INCLUSION CRITERIA

Subjects must be medically healthy and free of mental illness, take no medication, and must report no problems with their sexual function. They are required to be sexually active, including successful penetrative sexual intercourse acts.

For assessments of sexual function before and after the study subjects are required to complete a detailed daily diary recording their erectile activity for 7 days before the first study session, and for 7 days after completion of the study.

EXCLUSION CRITERIA

Persons having taken antidepressant or other medications likely to alter monoamine neurochemistry or cerebrovascular and cardiovascular function within 6 months prior to the study will be excluded.

Individuals will also be excluded if they have: a) evidence for an axis I psychiatric disorder (DSM-IV criteria), b) medical or neurological illnesses likely to affect physiology or anatomy, c) a history of drug (including BZDs) or alcohol abuse within 1 year or a lifetime history of alcohol or drug dependence (DSM IV criteria), d) smokers, e) diagnosis of a sexual disorder, f) criminal history.

Persons must exhibit no or only moderate alcohol use. Persons with current or previous regular use ( more than 4 weeks) of BZDs and excessive use of alcohol (more than 8 ounces/day) in the past or presence are ineligible to participate, as such drug use confound the results.

Individuals beyond age 50 are excluded because subjects beyond age 50 have a far greater likelihood of showing subtile, albeit clinical irrelevant disturbances in erectile function.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2002

Study Completion

April 1, 2004

Study Registration Dates

First Submitted

July 31, 2002

First Submitted That Met QC Criteria

July 31, 2002

First Posted (Estimate)

August 1, 2002

Study Record Updates

Last Update Posted (Estimate)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

April 1, 2004

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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