Introduction
Priapism is an erection persisting for over four hours, often
associated with pain. Most commonly, priapism is coupled with the
absence or reduction in intracavernosal arterial flow, known as ischemic
priapism, which implicates emergent intervention to prevent fibrosis of
corpora cavernosa and the subsequent risk of long-term erectile
dysfunction. Priapism incidence ranges from 0.3 to 1.5 per 100,000 men,
with approximately 30% drug-induced. Pharmacological interventions for
erectile dysfunction, including intracavernosal injection of erectogenic
agents (e.g., papaverine and alprostadil) as well as oral intake of
phosphodiesterase-5 inhibitors (PDE5i), are known causes of priapism.
While intracavernosal therapy’s role in priapism is well-evidenced,
priapism from PDE5i is only recorded by limited case reports. Recently,
a study demonstrated that priapism accounts for 0.7% of reported
adverse drug reactions (ADR) for PDE5is, suggesting that extensive
patient counseling regarding priapism when prescribing may be
unnecessary.
We aim to verify the low incidence of priapism among PDE5i users in a
large international dataset. Further, we aim to assess the differences
between different PDE5i products and common intracavernosal agents in
the development of priapism. We identify age groups at risk to help
practitioners better counsel their patients.