Editing Evaluation and Management of Erectile Dysfunction (section)

=== Intraurethral (IU) alprostadil ===

* '''Relies on the absorption of the medication''' into the surrounding corpus spongiosum, with passage via small vascular channels '''into the''' '''corpora cavernosa''', the main erectile bodies
* Known as MUSE (Medicated Urethral System for Erection)
* Uses a suppository inserted into the urethral opening that '''dispenses a semisolid pellet''' (1x3mm) '''of alprostadil''' (125, 250, 500, and 1000mcg dosages) '''into the distal urethra''' (3cm from the external urethral meatus)
* '''Inferior efficacy compared to PDE5 inhibitors and ICI'''
* '''Treatment option when:'''
** '''Patient prefers to avoid oral medication and avoid needles required for ICI medications'''
** '''PDE5i are contraindicated'''
** The main indications are patients who are non-responsive to PDE5 inhibitors resulting from damage of the autonomic penile nerve supply (e.g., radical prostatectomy, cystectomy, and trauma) or those who wish to use the therapy in combination with PDE5 inhibitors.
* '''The most common adverse events are genital pain, minor urethral trauma/bleeding, urethral pain or burning, and dizziness. Episodes of hypotension or syncope are rare. No reports of priapism'''
** Although episodes of priapism were not reported in IU alprostadil trials, the man should be thoroughly educated about priapism and instructed on safe responses and maneuvers in a prolonged erection situation.
* '''Contraindications to MUSE (3):'''
*# '''Hypersensitivity'''
*# '''Abnormal penile anatomy'''
*# '''Conditions that increase the risk of priapism'''
* '''For patients considering the use of IU alprostadil, an in-office test should be performed.'''
** Most studies proceeded with chronic treatment only in men who had erections firm enough for intercourse in response to in-office testing. The success rates among men who used the medication chronically, therefore, are relevant to responsive intra-office testing – not men with ED in general.
** IU alprostadil should not be prescribed until a man has undergone instruction in the method, an initial dose-titration in the office, and detailed counseling regarding possible adverse events and actions to take in response to potentially serious adverse events.
* '''MUSE seems safe for female partners,''' producing only a 5.8% incidence of vaginal burning or itching, '''although it should be used with a condom for intercourse with a pregnant woman'''