The Management of Erectile Dysfunction With Placebo Only (DAFA06)

A Single-Blind, Controlled, Randomized, Parallel-Group Study of the Efficacy of Patients' Awareness on the Composition of the Experimental Drug in the Treatment of Erectile Dysfunction.

Placebo-controlled randomized clinical trials (RCT) are the gold standard to provide applicable evidence for clinical practice. A vast number of RCTs for treatment of several disorders has shown a mean placebo effect of 30%. Erectile dysfunction (ED) is a high prevalent disease and its first-line therapy is oral phosphodiesterase type-5 inhibitor (iPDE5) (i.e., sildenafil, vardenafil and tadalafil). Although the placebo effect in iPDE5 RCT occurred at a rate as high as 50%, in the last decade, with the revolutionary discovery of effective pharmacotherapy for ED, oral iPDE5 has become one of the most common prescribed drugs for men. The objective of this study is to evaluate the influence of patients' awareness on the composition of the therapeutic drug in the outcomes of the oral treatment for ED.

Study Overview

• Status: Completed
• Conditions: Erectile Dysfunction; Impotence
• Intervention / Treatment: Other: Induction to efficient treatment; Other: Doubt to the efficacy of treatment; Other: Induction to ineffective treatment

• Study Type: Interventional
• Enrollment (Actual): 123
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• 18 years of age or older
• Complaint of ED for at least 6 months prior the start of the study, according to medical history and to the questionnaires IIEF, SEAR and QEQ.
• A stable heterosexual relationship.
• To be in good health prior the participation in the study, with no important clinical abnormalities, determined by: clinical history, physical examination, blood chemistry and hematology, urinalysis (If the standard values of the laboratory for these tests are not evidenced, subjects can be included if the researcher consider the changes as not clinically significant).

Exclusion Criteria:

• History of significant cardiovascular, pulmonary, gastrointestinal, hematological, neurological (including epilepsy), locomotor, immunologic, ophthalmic, metabolic, endocrine, thromboembolic, rheumatologic, cancer, kidney or liver disease.
• Diagnosis of psychiatric conditions, e.g. depression, anxiety, dysthymia, mania, panic, agoraphobia, social phobia, suicidal ideation, obsessive-compulsive disorder, post-traumatic stress, psychotic disorders, schizophrenia, alcoholism, dependence on psycho-active substances.
• History of HIV, hepatitis B or hepatitis C.
• Hyperprolactinemia or untreated hypothyroidism.
• Any condition, which, in the opinion of the investigator, may interfere with the participation of the subject in the study (e.g. difficulty to meet the requirements of the study, attend the consultations, answer the questionnaires).
• Report of significant clinical problems by the subject's partner, such as decreased sexual interest, pain during relations or other forms of sexual dysfunction that interfere in the relationship with the sexual partner.
• Patient or partner willing to undergo a surgical procedure during the study period, which may interfere in the results.
• Peyronie's disease, which may lead to impossibility to penetrate or cause pain during the sexual intercourse.
• Use of nitrates.
• Illiterate patient.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: A1; Arm 1 received an informative letter explaining that they were allocated to receive a substance for Erectile Dysfunction treatment.	Other: Induction to efficient treatment; Informative letters.
Placebo Comparator: A2; Arm 2 (A2) was written informed that they could or could not receive an active drug for ED treatment.	Other: Doubt to the efficacy of treatment; Informative letters.
Experimental: A3; Arm 3 (A3) was properly written informed to be using no effective drug for ED treatment.	Other: Induction to ineffective treatment; Informative letters

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
IIEF erectile function domain score	4 AND 8 Weeks
Quality of Erection Questionnaire (QEQ)	4 and 8 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
IIEF orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction domain scores	4 and 8 weeks
SEAR questionnaire	4 and 8 weeks
EDITS questionnaire	4 and 8 weeks
GEAQ questionnaire	4 and 8 weeks

Collaborators and Investigators

• Sponsor: Rio de Janeiro State University
• Investigators: Study Chair: Eloisio Alexsandro da Silva, MD, PhD, Laboratory for Translational Research in Urology

Study record dates

Study Major Dates

• Study Start: October 1, 2006
• Primary Completion (Actual): October 1, 2007
• Study Completion (Actual): January 1, 2008

Study Registration Dates

• First Submitted: April 15, 2009
• First Submitted That Met QC Criteria: April 15, 2009
• First Posted (Estimate): April 17, 2009

Study Record Updates

• Last Update Posted (Estimate): April 17, 2009
• Last Update Submitted That Met QC Criteria: April 15, 2009
• Last Verified: April 1, 2009

More Information

Terms related to this study

• Keywords: Erectile Dysfunction; Clinical Trial; Placebo; Placebo Effect; Sexual Dysfunction
• Additional Relevant MeSH Terms: Mental Disorders; Sexual Dysfunctions, Psychological; Sexual Dysfunction, Physiological; Erectile Dysfunction
• Other Study ID Numbers: DAFA06