Daily Tadalafil 5 mg Combined With On-Demand Sildenafil 100 mg for Treatment of Erectile Dysfunction in PDE-5I Non Responder Patients
1 other identifier
interventional
500
1 country
11
Brief Summary
The goal of this clinical trial is to evaluate whether daily dosing with tadalafil 5 mg combined with on-demand sildenafil 100 mg can improve erectile function in men with erectile dysfunction (ED) who do not respond to PDE5 inhibitor alone. The main questions it aims to answer are:
- Does the combination of daily tadalafil and on-demand sildenafil lead to a greater improvement in erectile function (measured by the IIEF-EF domain) compared with on-demand sildenafil alone?
- Is the combination therapy safe and well tolerated in this patient population? Researchers will compare:
- Group A: Daily tadalafil 5 mg plus on-demand sildenafil 100 mg
- Group B: Daily placebo plus on-demand sildenafil 100 mg to determine whether the combination regimen provides superior improvement in erectile function and patient satisfaction. Participants will:
- Undergo baseline assessment including medical history, physical examination, and laboratory tests.
- Be randomly assigned to one of the two treatment groups.
- Take the assigned medications for 12 weeks.
- Complete follow-up evaluations at 4, 8, and 12 weeks, including: International Index of Erectile Function (IIEF-15) questionnaire Erection Hardness Score (EHS) assessment Reporting of any adverse effects
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_4
Started Dec 2025
11 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
November 18, 2025
CompletedStudy Start
First participant enrolled
December 1, 2025
CompletedFirst Posted
Study publicly available on registry
February 6, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 1, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
June 1, 2027
February 6, 2026
February 1, 2026
1 year
November 18, 2025
February 2, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Change in International Index of Erectile Function-5 (IIEF-5) total score
The IIEF-5 is a validated 5-item questionnaire assessing erectile function, with total scores ranging from 5 to 25; higher scores indicate better erectile function.
from baseline to 12 weeks after starting treatment
Secondary Outcomes (3)
Change in Erection Hardness Score (EHS), assessed using the validated 4-point Erection Hardness Scale
from baseline to 12 weeks after starting treatment
Change in International Index of Erectile Function (IIEF-15) total score
from baseline to 12 weeks after treatment
Incidence and severity of adverse events graded according to CTCAE version 5.0
from baseline up to 12 weeks after treatment
Study Arms (2)
Group A
EXPERIMENTALDaily tadalafil 5 mg and on-demand sildenafil 100 mg
Group B
PLACEBO COMPARATORdaily Placebo and on demand sildenafil 100 mg
Interventions
daily dosing of Tadalafil 5 mg combined with on demand Sildenafil 100mg
Eligibility Criteria
You may qualify if:
- Sexually active male.
- History of ED for ≥6 months.
- Erectile function domain of IIEF-15 score \<17.
- Documented failure to respond to PDE-5I \[definition of non-responder patients are patients with ED who don't respond to maximum dose of PDE-5I on ≥4 occasions in spite of accurate timing and good sexual stimulation\].
- Stable sexual relationship ≥ 6 months.
You may not qualify if:
- Penile anatomical deformities or Peyronie's disease.
- Pelvic surgery or radiation.
- Active malignancy or severe systemic illness.
- Previous penile surgery of any kind, such as penile prosthesis, penile lengthening, penile cancer surgery, penile plication or grafting.
- Contraindication to PDE5i (High risk cardiac patients, patients on nitrates, hypotension).
- Using other treatments for ED e.g., Intra-cavernoasl prostaglandin injection therapy.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Mansoura Universitylead
- Cairo Universitycollaborator
- Ain Shams Universitycollaborator
- Aswan Universitycollaborator
- Luxor universitycollaborator
- Assiut Universitycollaborator
- Minia Universitycollaborator
- Alexandria Universitycollaborator
- Tanta Universitycollaborator
- October 6 Universitycollaborator
- Al-Azhar Universitycollaborator
Study Sites (11)
Urology and Nephrology Center, Mansoura University
Al Mansurah, Dakahlia Governorate, Egypt
Faculty of medicine, Alexandria University
Alexandria, Egypt
Faculty of medicine, Aswan university
Aswān, Egypt
Faculty of Medicine - Assiut University
Asyut, Egypt
Cairo University, faculty of medicine
Cairo, Egypt
Faculty of medicine, Ain Shams University
Cairo, Egypt
Faculty of medicine, Azhar University
Cairo, Egypt
Faculty of medicine, october 6 Univeristy
Cairo, Egypt
Faculty of medicine, Luxor university
Luxor, Egypt
faculty of medicine, Minya University
Minya, Egypt
Faculty of medicine, Tanta University
Tanta, Egypt
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- STUDY CHAIR
Ahmed A Shokeir, professor of urology
Urology & Nephrology Center, Masnoura university, Egypt
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 4
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
November 18, 2025
First Posted
February 6, 2026
Study Start
December 1, 2025
Primary Completion (Estimated)
December 1, 2026
Study Completion (Estimated)
June 1, 2027
Last Updated
February 6, 2026
Record last verified: 2026-02