Alprostadil and Penile Fibrosis Risk

Risk Stratification by Route of Administration

• The UK guidelines acknowledge penile fibrosis as a recognized complication of intracavernosal injection with reported incidence ranging from <1% to more than 20% 1
• The American Urological Association recommends intraurethral alprostadil as an alternative option and does not list fibrosis among its adverse effects, distinguishing it from intracavernosal injection 2

Mechanism and Risk Factors

• The AUA/SMSNA guidelines emphasize that corporal fibrosis leading to penile shortening results from untreated ischemic priapism (>36 hours), not from alprostadil itself 3
• Alprostadil alone is actually less prone to cause ischemic priapism compared to papaverine and phentolamine combinations, which counteract normal detumescence pathways 4
• Alprostadil alone is actually less prone to cause ischemic priapism compared to papaverine and phentolamine combinations, which counteract normal detumescence pathways 5

Clinical Monitoring Requirements

• The American Urological Association guidelines require in-office test doses with detailed counseling regarding adverse effects before prescribing either intracavernosal or intraurethral alprostadil 2