A Randomized Double-Blind Clinical Study of Intracavernosal OnabotulinumtoxinA Injection in Patients With Erectile Dysfunction Refractory to Phosphodiesterase-5 Inhibitors

This study aims to evaluate the clinical efficacy of intracavernosal treatment with onabotulinumtoxinA (Botox) in 114 men aged 30 years or older with erectile dysfunction who have not responded to first-line oral pharmacological treatment.

For this purpose, the effects of onabotulinumtoxinA are compared with those of a placebo consisting of an intracavernosal injection of physiological saline. The study is patient-blinded.

Participants in the experimental group receive 100 U of onabotulinumtoxinA diluted in 1 mL of physiological saline, while participants in the control group receive 1 mL of physiological saline.

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Key information

Conditions

Erectile Dysfunction Genital Diseases Genital Diseases, Male Male Urogenital Diseases Mental Disorders Sexual Dysfunction, Physiological Sexual Dysfunctions, Psychological Urogenital Diseases

Age range

30 year and older

Sex eligibility

Male

Study type

Interventional

Phase

Phase 2

Primary location

Clinica Universidad de Navarra

Pamplona, Navarre, 31008, Spain

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patients diagnosed with erectile dysfunction (ED) with an inadequate response to phosphodiesterase type 5 inhibitors (PDE5 inhibitors) or to intracavernosal injections with Caverject or Bimix/Trimix (IIEF-15 questionnaire score ≤12).
Patients aged 30 years or older.
Patients who have provided informed consent to participate in the study.
Patients who, in the investigator's opinion, are able to comply with all clinical trial requirements.
Patients who agree to attend follow-up visits and undergo the required assessments.

Exclusion criteria

Severe infections or diseases, or hepatic, renal, or bone marrow insufficiency, that, in the investigator's opinion, contraindicate participation in the study.
Known hypersensitivity to onabotulinumtoxinA (BoNT-A).
Patients who do not consent to participate in the study.
Patients younger than 30 years.
Patients who underwent robotic radical prostatectomy less than 6 months prior to study enrollment.
Patients with a known history of neurogenic injury.
Patients with a history of radiation therapy.
Patients with a known psychiatric disorder.
Patients with anatomical abnormalities of the penis.
Patients who do not agree to, or are unable to commit to, attending the scheduled follow-up visits.

Treatment and study plan

OnabotulinumtoxinA (Botox ®) Injections

Drug

OnabotulinumtoxinA 100 U diluted in 1 mL of physiological saline, administered by intracavernosal injection

Saline (0.9% NaCl)

Drug

1 mL of physiological saline, administered by intracavernosal injection

Primary outcomes

BOTOX efficacy

Time frame: 6 months

Check if intracavernosal injections of onabotulinum toxin A improve erectile dysfunction in refractory patients to oral medication using questionnaires.

Sponsors and collaborators

Lead sponsor

Clinica Universidad de Navarra, Universidad de Navarra

Other

Registry information

Acronym: BTXDE

Important dates

Study start: 2024
Primary completion: 2026
Study completion: 2026
First posted: Sep 22, 2026
Registry last updated: Sep 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed