Trial Review

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12625000738426p
Ethics application status
Submitted, not yet approved
Date submitted
9/04/2025
Date registered
11/07/2025
Date last updated
11/07/2025
Date data sharing statement initially provided
11/07/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
Quantification of retrograde ejaculation secondary to Silodosin and Alfuzosin in adult males: a randomized, blinded, placebo-controlled, crossover study
Scientific title
Quantification of retrograde ejaculation secondary to Silodosin and Alfuzosin in adult males being treated for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a randomized, double-blinded, placebo-controlled, crossover study
Secondary ID [1] 314176 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Retrograde ejaculation 337028 0
Lower urinary tract symptoms 337029 0
Benign prostatic hyperplasia 337030 0
Condition category
Condition code
Renal and Urogenital 333481 333481 0 0
Other renal and urogenital disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Each participant will rotate between each of the 3 crossover groups. Treatment in each crossover group will last 30 days. By the end of the study, each participant will have been treated with 30 days of placebo, Silodosin and Alfuzosin. Between crossover, there will be a washout period of 7 days to allow complete clearance of medication from the participant’s systems.
The interventions being studied are Silodosin and Alfuzosin.
This clinical trial involves 3 crossover groups:
1. Silodosin (8mg, oral capsule, daily, in the morning with meal)
2. Alfuzosin (10mg, oral tablet, daily, in the morning, with meal)
3. Placebo (oral microcellulose capsule)
Intervention code [1] 330777 0
Treatment: Drugs
Comparator / control treatment
The comparator treatment is Alfuzosin (10mg, daily, in the morning with meal).
The control treatment is placebo (oral microcellulose capsule).
Control group
Placebo

Outcomes
Primary outcome [1] 341060 0
Semen analysis for retrograde ejaculation. Parameters within semen analysis consist of Sperm Motility, Morphology, Velocity, Volume, Concentration, Count. This will be assessed as a composite outcome.
Timepoint [1] 341060 0
One baseline measurement prior to treatment, followed by 15 days and 30 days (primary timepoint) post-commence of each treatment (placebo, Alfuzosin, Silodosin). A total of 7 measurement time points (baseline and 2 measurements per treatment).
Secondary outcome [1] 445996 0
Voiding flow rate
Timepoint [1] 445996 0
One baseline measurement prior to treatment, followed by 15 days and 30 days (primary timepoint) post-commence of each treatment (placebo, Prazosin, Silodosin). A total of 7 measurement time points (baseline and 2 measurements per treatment).
Secondary outcome [2] 447355 0
International Prostate Symptom Score
Timepoint [2] 447355 0
One baseline measurement prior to treatment, followed by 15 days and 30 days (primary timepoint) post-commence of each treatment (placebo, Prazosin, Silodosin). A total of 7 measurement time points (baseline and 2 measurements per treatment).
Secondary outcome [3] 447356 0
International Index of Erectile Function
Timepoint [3] 447356 0
One baseline measurement prior to treatment, followed by 15 days and 30 days (primary timepoint) post-commence of each treatment (placebo, Prazosin, Silodosin). A total of 7 measurement time points (baseline and 2 measurements per treatment).
Secondary outcome [4] 447358 0
Men Sexual Health Questionnaire
Timepoint [4] 447358 0
One baseline measurement prior to treatment, followed by 15 days and 30 days (primary timepoint) post-commence of each treatment (placebo, Prazosin, Silodosin). A total of 7 measurement time points (baseline and 2 measurements per treatment).

Eligibility
Key inclusion criteria
Inclusion criteria
• Adult men (18 years and over) diagnosed Obstructive LUTS to be treated with tamsulosin as part of normal clinical treatment
• Normal ejaculatory function prior to starting tamsulosin
• Normal erectile function prior to starting tamsulosin
Minimum age
18 Years
Maximum age
No limit
Sex
Males
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria
• Severe LUTS with post-void residual urine volumes greater than 300ml requiring immediate intervention
• Ejaculatory dysfunction prior to starting tamsulosin
• Erectile dysfunction prior to starting tamsulosin
• Previous exposure to a-1B medications for LUTS
• Previous transurethral resection of prostate, bladder neck incision or radical prostatectomy
• History of hypertension or obstructive sleep apnoea
• History of uncontrolled diabetes (HbA1c >7%)
• History of renal impairment (eGFR < 60mL/min/1.73 m²)
• Morbid obesity (BMI >40)
• Abnormal semen analysis


Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation involves contacting the holder of the allocation schedule who is off-site
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Phase
Phase 4
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
Power analysis assumptions
Significance level (a, one-sided) = 0.05
Power (1-ß) = 0.8
Minimal detectable difference in means = 0.43
Standard deviation was assumed to be paired due to crossover and repeated measures in the same participant, with a value of 1 (as there is currently no data regarding an appropriate standard deviation for sperm count in a population relevant to this study).
Calculations were conducted using: https://hedwig.mgh.harvard.edu/sample_size/js/js_crossover_quant.html

Number of patients required = 35
Considering a 10% drop-out rate = 35/0.9 = 39
Therefore, a minimum number of 39 participants are required, which equates to 13 participants in each of the 3 crossover groups. Toowoomba Hospital will recruit a minimum of 13 participants into each crossover group (totalling 39 participants). For convenience of block randomisation, 15 participants will be recruited into each group, totalling 45 participants.

Minimal detectable difference in means was calculated based on the primary outcome sub-variable, sperm count. A one-sided significance level was assumed as it is expected that sperm count will decrease following intervention. It was assumed that normal sperm count in an Australian male is 69 x10^6 /ejaculate. Subfertility (sperm count <39 x10^6 /ejaculate) was deemed the clinically significant post-intervention outcome.



Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/09/2025
Actual
Date of last participant enrolment
Anticipated
19/12/2025
Actual
Date of last data collection
Anticipated
27/02/2026
Actual
Sample size
Target
45
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
QLD
Recruitment hospital [1] 27737 0
Toowoomba Hospital - Toowoomba
Recruitment postcode(s) [1] 43927 0
4350 - Toowoomba

Funding & Sponsors
Funding source category [1] 318693 0
Charities/Societies/Foundations
Name [1] 318693 0
Toowoomba Hospital Foundation
Country [1] 318693 0
Australia
Funding source category [2] 319433 0
Commercial sector/Industry
Name [2] 319433 0
Sapyen Co
Country [2] 319433 0
Australia
Primary sponsor type
Individual
Name
Dr Benjamin Huang - Toowoomba Hospital, Darling Downs Health, Queensland Health
Address
Country
Australia
Secondary sponsor category [1] 321399 0
None
Name [1] 321399 0
Address [1] 321399 0
Country [1] 321399 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 317302 0
Darling Downs Hospital and Health Service Human Research Ethics Committee
Ethics committee address [1] 317302 0
Ethics committee country [1] 317302 0
Australia
Date submitted for ethics approval [1] 317302 0
29/04/2025
Approval date [1] 317302 0
Ethics approval number [1] 317302 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 140622 0
A/Prof Devang Desai
Address 140622 0
Toowoomba Hospital, Darling Downs Health, Queensland Health - Private Mail Bag 2, Pechey St, Toowoomba City QLD 4350
Country 140622 0
Australia
Phone 140622 0
+61 7 4616 6000
Fax 140622 0
Email 140622 0
[email protected]
Contact person for public queries
Name 140623 0
Benjamin Yili Huang
Address 140623 0
Toowoomba Hospital, Darling Downs Health, Queensland Health - Private Mail Bag 2, Pechey St, Toowoomba City QLD 4350
Country 140623 0
Australia
Phone 140623 0
+61 426502143
Fax 140623 0
Email 140623 0
[email protected]
Contact person for scientific queries
Name 140624 0
Benjamin Yili Huang
Address 140624 0
Toowoomba Hospital, Darling Downs Health, Queensland Health - Private Mail Bag 2, Pechey St, Toowoomba City QLD 4350
Country 140624 0
Australia
Phone 140624 0
+61 426502143
Fax 140624 0
Email 140624 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

TypeCitationLinkEmailOther DetailsAttachment
Study protocol  [email protected] BH1_FINAL_Study_Protocol_Alpha_Blocker_RCT.docx
Informed consent form  [email protected] BH1_FINAL_PICF_Alpha Blocker.docx


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.